Can personalised learning strategies such as concept

mapping and cooperative learning be used to

overcome blocks to learning caused by difficult to

understand topics in biology.

Candidate number: 120127735

Supervisor: Dr Jonathan Graves

Word count: 4997

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Table of contents

Biological introduction ………………………………………………………………………………… 2 - 5

Pathogens and antibiotic resistance …………………………………………………………….. 2 - 3

Case studies …………………………………………………………………………………………………4 - 5

Educational introduction ………………………………………………………………………………6- 10

Educational placement ………………………………………………………………………………… 6 - 7

Educational background ……………………………………………………………………………… 7 - 10

Educational aims and objectives …………………………………………………………………...10

Assessment of effectiveness …………………………………………………………………………..10 - 12

References ……………………………………………………………………………………………………..13-15

Appendix …..……………………………………………………………………………………………………16 – 53

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Biological Introduction

Pathogens

The Oxford Dictionary definition of a pathogen is “a bacterium, virus, or other microorganism

that can cause disease”(Stevenson, 2010), with the link between diseases and pathogens often

being highly specific (Singleton, 1997). Pathogens are of major interest to biologists, especially

those that directly or indirectly impact humans. There is vast research into how to treat

pathogens, but also interest in their biochemistry, microbiology and evolution. Pathogens have

incredible phylogenetic diversity (Alberts et al, 2002); also within each group of pathogens

there is huge diversity in size, shape and lifestyle. Pathogens can be obligate, where they only

replicate within the cells of the human body; or facultative, where they replicate in the

environment then infect their host. To survive and replicate pathogens must complete the five

stages of pathogenicity which are; adhere to host tissues, invade host tissues, multiply in host

tissues, evade host defences, and cause damage (Williams, Ketley and Salmond, 1998; Alberts et

al, 2002). All pathogens evolve specific ways to enter the host, and avoid their immune system.

Bacteria are tiny, single-celled organisms, which are found everywhere on earth (Singleton,

1997). They are the only known pathogenic prokaryotes (Campbell and Reece, 2011).

Prokaryotes are different from eukaryotes in several ways (Singleton, 1997). They have no

nuclear membrane, and contain simple chromosomes. They don’t reproduce by mitosis or

meiosis, but by binary fission or gene transmission. They lack internal, membrane bound

organelles, and are devoid of mitochondria and chloroplasts. The cell walls are made of

peptidoglycan, which is why antibiotics only destroy bacterial cells and not human cells. Illness

is caused by bacteria producing either exo or endotoxins (Campbell and Reece, 2011). The

difference being exotoxins are proteins secreted by certain bacteria, where as endotoxins are

the lipopolysaccaride parts of the bacterial cell walls, and are only released when the bacteria

begins to break down after death.

Viruses are even smaller than bacteria; they range from 10-300 µm (Wyss and Eklund, 1971).

They are simply nucleic acid surrounded by a protein coat, known as the capsid, which is

sometimes enclosed by a lipid envelope (Voyles, 1993). Their genomes are unconventional and

can be double or single stranded DNA or RNA, but never both. They are intracellular parasites

(Voyles, 1993), they have no metabolic machinery of their own (Wyss and Eklund, 1971), and

manipulate hosts enzymatic apparatus to produce more viruses, thus are reliant on host cells to

survive and replicate. They’re effective pathogens as a single viron which infects a host cell can

produce thousands of new virons (Alberts et al, 2002). Viruses are different from all other

microorganisms for two reasons; firstly they have no ribosomes or other cellular organelles,

secondly in RNA viruses all genetic information is encoded in RNA (Fenner et al, 1974).

Pathogenic fungi make up around 30% of all known species of fungi (Campbell and Reece, 2011).

They tend to be pathogens of plants, and can produce compounds in crop plants which are toxic

to humans. This is of high interest to researchers due to food security issues. Fungi tend not to

infect animals as much as they do plants, but there are around 500 species of fungi that are

pathogens to animals. Mycosis is the term used for an infection caused by a fungus; systemic

mycoses can cause very serious illnesses by spreading throughout the body. Pathogenic fungi

are difficult to treat without harming the host, as many antifungal treatments are damaging.

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They also have complex life cycles and drugs don’t typically treat all stages, meaning pathogenic

fungi can evade treatment (Alberts et al 2002).

Host defences

Pathogens enter the body via any interface with the environment. The skin often acts as a

protective barrier from pathogens (Singleton, 1997), meaning that they mainly gain entrance

via the mouth, leading to mucous membranes which are vulnerable to infection. However if the

skin is broken via a wound or bite, the pathogen can enter directly into the body.

Pathogens cause disease by many different mechanisms, for example producing toxins that stop

specific physiological processes; or invading cells and tissues, where toxins may also be

produced (Singleton, 1997). The body’s physiological response to an infection is known as

sepsis. The body defends itself against attack from pathogens through several mechanisms. The

body’s first barrier to pathogens is the skin. Then mucous membrane secretions discourage

pathogens due to their antibacterial qualities. Specialised cells called phagocytes then destroy

anything that is seen as foreign to the body. Finally antibodies are released by the body’s

immune system as a response to specific pathogens. Hosts can also have immunity to pathogens

and artificial immunity can be produced via the use of vaccines (Wyss and Eklund, 1971).

Antibiotic resistance

Evolution of bacterial strains to be resistant to antibiotics is a huge threat to public health. Due

to the rapid reproduction of bacteria, resistant bacteria can produce huge resistant populations

in very short time periods (Campbell and Reece, 2011). Antibiotics stop the peptidoglycan

bacterial cell wall from forming, causing osmotic lysis, and cell destruction. There is a selection

pressure for bacteria which are not destroyed by antibiotics; this enhances the production of

large resistant populations. Both vertical and horizontal gene transfer can spread resistant

genes throughout populations. A mutation can cause resistance by either altering a target

protein or enzyme within the bacterial cell so the antibiotic can no longer affect it, or by

preventing the antibiotic from entering the cell (Boyle and Senior, 2008).

Antibiotic resistance has led to such public health scares as MRSA, where there are no

antibiotics to treat them (Boyle and Senior, 2008). It is generally caused by over-prescription of

antibiotics by doctors, to treat infections that may not even be caused by bacteria. Made worse

when patients don’t finish their courses of antibiotics, meaning even partially resistant bacteria

can cause an infection.

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Further your learning HIV – Will science ever find a cure?

Human immune- odeficiency virus (HIV), the virus that causes AIDS, targets specific cells in the immune system, known as T cells (Boyle and Senior, 2008).

HIV is a retrovirus, carrying the enzyme reverse transcriptase. Once the virus enters the host cell it uses this enzyme to make viral DNA from viral RNA. The viral DNA is incorporated into the hosts own DNA, allowing the production of thousands of new viruses. This process causes the weakening of the immune system (Campbell and Reece, 2010) that leaves sufferers vulnerable to other infections such as tuberculosis and malaria. The main issue in the treatment of HIV is the fast evolution of the viruses’ surface proteins meaning that anti-viral drugs rapidly lose effectiveness (Boyle and Senior, 2008).

However there have been recent developments by scientists (Hayden, 2015), who have discovered an antibody (3BNC117) that reduces levels of the virus in humans. In clinical trials, 29 participants were tested, 8 of them were given the highest dose of 3BNC117, and this was found to reduce virus levels by between 8 and 250 times. However there are still issues; this treatment is incredibly expensive, with one course of antibodies costing thousands of dollars and most sufferers live in poorer countries. Also the rapid evolution of HIV still effects this treatment with patients who received the highest dose of antibody finding it was 80% less effective after 28 days. Scientists suggest that this new antibody will need to be used in conjunction with other antibodies to combat this problem.

The Ebola epidemic - here to stay?

The infamous Ebola virus has caused over 10,000 deaths in 2014 alone (CDC, 2014). The recent outbreak was caused by the Zaire species (Nice, 2014). With a fatality percentage of 69%, it is thought to be the most virulent species, begging urgent research attention.

The Ebola virus owes its virulence to the mechanisms it uses to disarm the immune response. The virus inhibits cells that signal for the T-cells to destroy them before infection spreads. With no T-cell activation, there is no activation of antibodies. From here the virus travels in the blood to the organs, and causes macrophages to release coagulants to clot the blood causing haemorrhaging (Servick, 2013).

Current treatments for Ebola include blood transfusions from Ebola survivors, but research is also looking into two vaccines that may be able to stop the disease (Nice, 2014). Research also shows that survival may be down to genetics, as survivors have more activated T-cells due to possessing a different gene variant (Servick, 2013). Much research is also going into making the diagnosis of Ebola easier with the creation of a rapid diagnostic kit.

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Can bacteria really control behaviour?

Weird Wolbacia

Wolbacia bacteria which live inside the reproductive tissues of Arthropods are famous for being able to change their hosts’ physiology to increase their chance of being passed on to offspring (Werren, 1997). The Wolbacia bacteria are only passed on via female hosts, this leads them to change their hosts to make sure that they maximise their population. In parasitic wasps Wolbacia induce parthenogenesis in hosts. This means that offspring can form from unfertilised eggs; this guarantees that the bacteria will be present in the offspring. It has also been seen in crustaceans that Wolbacia causes the feminization of genetic males. The bacterium converts males into reproductively competent females. All of these mechanisms give a selection advantage to the bacterium that has led to them being widespread throughout the animal kingdom.

Bizarre Buchnera

Buchnera are round-shaped bacteria which live in specific cells called bacteriocytes in most aphid species (Shigenobu et al, 2000). These bacteria are maternally transmitted to eggs, and neither the aphid nor buchnera can reproduce alone. These bacteria provision the aphids with essential amino acids (Douglas, 1998), which are not present in the sticky phloem sap on which the aphids feed. In return the bacteria live within the aphid, and are passed on generation after generation.

Bacteria and the dinosaurs

Bacteria are important in a process called exceptional preservation, where structures like skin, feathers and organs which are not normally preserved are fossilised (Franzen, 1985). This has led to major discoveries such as theropod dinosaurs were actually covered in feathers.

The process of exceptional preservation occurs when an organism dies in environments with certain characteristics, for example, places where scavengers can’t eat the carcasses and anoxic environments so that bacteria can’t degrade it. These tend to be lakes or ash falls from volcanoes. However microbial mats have also been found to allow exceptional preservation.

In Grube Messel site in Germany there are fossils which are fully articulated, and some soft tissue even remains. When a PhD student examined the fossils with an electron microscope, they found the fossil to be made up of rod and spherical microbes. From this they deduced that there was a layer of bacteria on the underside of the body, which had become petrified when the carcass landed on them. These bacteria were then cemented in place by organic material from plants. These sorts of discoveries can tell us a lot about the past, and evolution.

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Educational introduction

Educational placement

High Storrs School is an above average sized school with 1596 students, aged 11-18. It has been

designated a specialist school in Performing Arts, Maths and Computing. The 2013 Ofsted

inspection deemed the school “good” due to the above average GCSE attainment of students and

the good and sometimes outstanding teaching. Students’ behaviour was deemed “outstanding”,

which is consistent with my observations. I observed 17 lessons; six year 8 lessons, with pupils

aged 12-13 years, where I saw a mix of sets, from the highest set to the lowest set. Eleven year

12 lessons, with pupils aged 16-17, of the same class.

I taught one lesson to the year 12 class that I had been observing; there were 17 mixed ability

students in this class. During my time at the school they were preparing for their exams and

there practical exam (EMPA) so I was asked to teach a revision session. As I wanted this to be a

useful lesson for them I asked them what topics they would like to revise. They suggested

mitosis and meiosis or antibiotics. I later was asked to teach them a topic that would be on their

EMPA so I ended up teaching a lesson on pathogens and antibiotics.

From my observations of classes across all age ranges I saw that students had better

engagement when:

1) They were given short activities to do and then move on quickly to the next activity. This

reduced boredom with an activity and increased engagement.

2) When lessons were made interactive, whether it be that students were involved in a

discussion, or there was a practical. Students remained engaged when they were

allowed to physically do things in lessons.

Students tended to lose interest:

1) During cross over between activities, if the next activity wasn’t immediately ready.

2) When they spent too long on activities or the teacher spent too long explaining an idea.

From this I could see that it was necessary to make sure that all activities are ready for the

students one after another. To make sure that there are short introductions and instructions to

each topic. To make sure that activities are interactive and engaging. It is also important for

students to feel that they are in charge of their learning.

Implementation

From observations of both year 12 and year 8 classes I saw that students learn information via

rote learning. Students tend to recall information, not necessarily make links between concepts.

When year 12’s answered practice exam questions they would often struggle and need help

when a question was asking them to apply their knowledge, rather than just recall. The students

suggested they struggled with antibiotic resistance – this may be due to the fact that this

concept draws from other areas of biology, such as evolution, and without making those links it

could be a confusing concept. I will incorporate concept mapping into my lesson plan. This could

help the students make the transition from rote learning to meaningful learning that is

necessary for higher education.

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I also observed that students were most engaged with a task when they were allowed to work in

groups. They would discuss ideas with each other and so were better able to understand and

answer questions during and after these activities. I will incorporate collaborative learning into

my lesson in the form of study groups. By getting students to study together and explain

challenging concepts to each other I hope that confusing concepts become clearer, and more

memorable, when explained by a group member.

Educational background

Introduction

Blocks to learning are especially detrimental in the sciences; this is due the inter-relatedness

between topics and concepts within science disciplines. Within Biology it is important to be able

to draw knowledge from many different areas to allow interpretation of information. It is

integral to progression in biology that individuals can form these links between ideas and

different topics. When this does not occur, it is often difficult for students to understand certain

concepts, due to these blocks to learning. Less students’ progress into science subjects at

tertiary education, this may be due to these blocks to learning that are hard to overcome

without the necessary learning strategies. Strategies such as concept mapping and collaborative

learning could help students to understand difficult topics in biology, by helping them to make

connections between different topics, and draw information from many different areas of

biology.

Blocks to learning faced by students

Blocks to learning can be detrimental to students especially in science, often inhibiting their

progression into tertiary education. It is important to understand what blocks to learning are

faced by students; once the blocks are understood then learning mechanisms can be put in to

place to overcome them. Students often find topics difficult to understand if they have

previously misinterpreted or have not assimilated information related to the topic (Williams et

al 2012). There is also a suggestion that students struggle with ideas that relate to other

information within the topic or even outside the topic (Shanahan, Fisher and Frey, 2012), this is

because understanding difficult concepts is centred on an individual’s prior knowledge of the

subject. Students also struggle to understand ideas if they are complex with many components

(Graesser, Leon and Otero, 2002), especially where there are connections between components.

This is due to students learning primarily through rote learning, which is centred around

memorisation of information, this makes it difficult for students to make connections between

different topics.

Constructivist theory

Constructivist theory and learning approaches such as scaffolded knowledge integration

framework can be used to address blocks to learning, as are directly linked to the issues

surrounding accumulation of previous knowledge. The theory of constructivism was founded in

the 1980’s due to Jean Piaget’s work (Glynn, Yeany and Britton, 1991). He suggested that

humans construct knowledge based on previous information and experiences with the

environment. Individuals thus construct new knowledge by adding or modifying existing ideas

that they possess (Keogh and Naylor, 1996). However previous knowledge can be detrimental

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to students learning, especially misconceptions, which make it difficult for students to

understand or incorporate new information (Thompson and Zamboanaga, 2003).

Scaffolded knowledge integration framework is a teaching approach within the constructivist

theory (Williams et al 2012) that emphasises the importance of learning by adding, sorting and

reorganising scientific ideas. The key aims behind this theory are; using activities which prompt

students to think about how ideas are connected, learning from others using discussion and

debates, and allowing for a learning technique which can be applied to numerous problems.

Concept maps

Concept maps are a technique that can be implemented to allow students to overcome blocks in

their learning caused by difficult to understand ideas. Concept maps which were first proposed

by Joseph Novak, are thought to facilitate meaningful learning (Okebukola and Jegede, 1989),

where a person purposely relates new knowledge to relevant knowledge they already have.

Rather than rote learning where knowledge is randomly incorporated into the cognitive

structure (Novak, Gowin and Johansen, 1983). Concept maps are graphical representations of

knowledge (Novak and Cañas, 2008). They include “concepts” which are placed inside circles;

relationships between concepts which are represented by a connecting line, and a word is

placed on the line to identify the relationship between concepts. Constructivist theory suggests

that knowledge is constructed based on what an individual already knows (Novak 1991), and

concept maps can be used to organise knowledge and relate it to what is already known by the

student, which allows meaningful learning. However students must choose to learn

meaningfully (Novak and Cañas, 2006); the teacher only has indirect control over this by

motivating students. Students need to attempt to incorporate new meanings into their prior

knowledge rather than just memorising the information on a superficial basis. They initially

struggle with concept mapping due to previous rote learning, the transfer to meaningful

learning is problematic for students (Heige, 2012).

Concept maps can be used as an effective revision tool. To create new knowledge, information

must be moved from the short-term into the long-term memory (Watson and Gable 2010); the

working memory facilitates this. The working memory has a limited capacity of 5-9 pieces of

information, once the working memory is overloaded there are negative effects on learning and

understanding. Concept maps can help students to learn more information and increase

understanding as the concepts are linked, creating chunks of information, (Heige 2012) which

make large amounts of information more manageable, meaningful and memorable. As well as

making relationships between new and old information, concept maps allow more to be

remembered by the working memory (Novak and Cañas, 2006). Concept mapping has also been

found to reduce anxiety in students when they were learning difficult concepts (Okebukola and

Jegede, 1989). Unfortunately exams don’t necessarily require anything more than rote learning,

for example recalling statements or definitions. Meaningful learning can actually make these

exams difficult as the assimilation of information into frameworks stops them being able to

recall things such as definitions (Novak and Cañas, 2006).

Current studies into the effectiveness of concept mapping

A meta-analysis of studies (Heige, 2012) which used concept mapping as a learning technique

reported that it is a more effective technique for retention of information than ‘traditional’

learning methods such as reading text, lecture style lessons or discussions. Heige (2012) also

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found that 54% of 171 kinesiology undergraduates ranked concept maps as the most beneficial

learning technique, and 71% ranked them as one of the top three learning techniques. 2/3rds of

students said they used concept maps to help them answer exam questions. Conceiҫão and

Taylor (2007) looked at concept mapping with student nurses. They found that concept

mapping allowed students to make new connections to information, integrate previous

knowledge and validate existing knowledge. Briscoe and LaMaster (1991) introduced concept

mapping to Biology college students. They found that it helped students to solve novel problems,

and answer questions that required synthesis of information. However they found that whether

students chose to learn meaningfully depended on what kind of exam questions students

anticipated. Regis and Albertazzi (1996) looked into using concept maps with chemistry

students aged 16-18. They found that on average students needed four to six 45 minute sessions

to understand how to construct a concept map. As the students went on their concept maps

developed and became more complex, leading to better linkages between information. They

also allowed for teachers to see where there were misconceptions in students’ previous

knowledge. They encouraged students to discuss their maps and be critical of them to

encourage active learning. They found that students found concept maps so useful they started

using them in other subjects.

Collaborative learning

Learning with others can be particularly helpful when students face blocks in their learning. By

discussing the difficult to understand concepts in biology students can start to build up links

between other concepts and integrate them into their previous knowledge. “Cooperative

learning is when students work together in small heterogeneous groups performing group tasks

set by the teacher” (Shoval and Shulruf, 2011). Children build their own understandings and

meanings about information through activity, where they can discover and internalise new

information (Glynn, Yeany and Britton, 1991). Children also learn though social interaction

(Nyikos and Hashimoto, 1997). Social constructivism emphasises that social interaction is

incredibly important in individuals cognitive development as information experience through

social activity is internalised. Nyikos and Hashimoto (1997) wanted to see if collaborative

learning was useful in adults. They observed a graduate teacher education class where there

was a collaboratively written paper. They found that group members with more knowledge

helped their less knowledgeable colleagues. They found that discussing problems made them

easier to solve. In general cooperative learning was successful as rated by the students.

Conclusion

It is clear that students struggle due to difficulty understanding complex concepts. These blocks

in learning are caused when previous knowledge is either misinterpreted or not assimilated

correctly, this causes new information to become challenging to students. Constructivists

suggest this is because the ease at which students learn new information is based on what

knowledge they already possess. It has been shown in previous studies that concept mapping

and collaborative learning are effective techniques in overcoming these difficult ideas, and are

useful to students tackling these blocks to learning. Secondary education exams don’t often ask

for more than rote learning, so students tend to memorise information, and then struggle in

analytical questions. However students need to progress to learning meaningfully and have

strategies to overcome blocks in their learning to advance to tertiary education, without this we

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find a decrease in the number of students progressing into more complex subjects like science

and maths.

Educational aims and objectives

Aims:

- Tackle the issue of blocks to learning in challenging topics such as antibiotics.

- To use concept maps to encourage students to understand how different areas of

biology interact.

- To use collaborative learning to reinforce learning in a social context.

- To encourage students to start assimilating information in a meaningful way, rather

than by rote learning.

- To allow students the mechanisms to approach revision using meaningful learning.

Objectives:

- To be able to say how pathogens cause disease.

- To be able to explain how pathogens enter the body, and what pathogens infect different

systems of the body.

- To understand how antibiotics destroy bacteria.

- To understand what antibiotic resistance is and how it evolves.

- To have drawn a concept map, and to understand why they are useful in terms of

meaningful learning.

- To understand how different revision techniques can be effective.

Assessment of effectiveness

Starter and introduction of the topic:

The starter was received well by the students. It was good to see what they already knew, and

they understood that that is how they should approach their future revision. In general I spent

too much time explaining the background information for a revision session and there should

have been more time spent focusing on interpreting the information instead. Students were able

to recall the information, and didn’t need it explained again. The teacher suggested that I should

have asked the students to feedback their ideas or answers more so they were actively

contributing to the lesson.

Activity 1 – Concept mapping:

The students found concept mapping difficult to do, this is because they are used to rote

learning, and for example they suggested that they preferred using lists to revise. It is difficult to

change the students’ technique of learning in one lesson, especially as studies suggest they need

4-6 sessions to fully understand how to use of concept maps. When asked if they would use it in

their revision again only one student said yes. However they did understand how to use them,

and why they were useful, and by the end of the task they were all able to see how different

concepts linked together.

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The teacher suggested that I should have given more detailed instruction on how to construct a

concept map; I could have been more thorough in my explanation. I also didn’t fully explain the

concept map I constructed myself, and they teacher suggested it would have been useful for the

students to understand why and how I constructed it.

Activity 2 – Study groups:

The students worked reasonably well in study groups and all managed to get something

prepared to show each other. There were many different ways that students used to

demonstrate the topic they had been given. Several students drew storyboards, several just gave

explanations, several turned their topic into a story, creating characters, and one student made

a rap about his topic and one played charades and made her group guess what pathogen it was.

It worked well in that several students said they would remember the topic because of how it

had been portrayed to them by their peers, but also because they had to fully understand it to

then teach it to others. Collaborative learning is extremely important in internalising

information and knowledge, especially when it is done in a memorable way. The teacher felt I

should have taken advantage of the fact that the students were of differing abilities and put

them in groups myself so that they are in groups of the same ability. Although this would be

beneficial as higher ability groups could have been given harder work, I feel that for two reasons

it was better to let them choose their own groups; 1) if they were to form study groups

themselves they would do so in friendship groups, 2) if the groups are mixed ability that means

that higher ability students could help lower ability students to understand concepts, and they

would be forced to think about the idea in an easily explainable way.

Activity 3 – Who wants to be a millionaire quiz:

The students really enjoyed this part of the lesson, and were engaged though out. It was good to

see how much they had learnt through the lesson or how much they remembered. I was starting

to run out of time during this part of the lesson and I would have liked to have taken more time

to explain the answers thoroughly.

Conclusion:

I think that the lesson was a success overall, and the students enjoyed the lesson on the whole.

Due to the nature of the lesson it probably wasn’t the best lesson at conveying the topic, it was

primarily a lesson to teach students how to deal with challenging concepts and how to approach

revision in a meaningful way, and I feel the lesson did this well. By the end of the lesson

students seemed to be able to apply knowledge to questions they were asked, as well as being

able to compose their own learning resources to effectively teach other students. The teacher

was very positive about my lesson, and said I was confident in my delivery and the students

were responsive to me. They were happy to get involved in discussions and activities, and there

were no behaviour issues.

Her final feedback was “A great, entertaining lesson. Students really enjoyed the interactive

nature of the lesson. All students were engaged and focussed throughout. You could have done

something on interpreting exam questions, structuring long answer questions.” I think that

having an exam question in the last 10 minutes of the lesson would have been useful, especially

questions that involved linking concepts. In retrospect I should have put some other worksheets

or exam questions in their resource pack.

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Students were hesitant towards both concept mapping and collaborative learning, this may be

due to the way they have always learnt, and it is difficult to change their entire learning process

in one lesson. However they could all see the benefits of learning in this way. In secondary

learning they aren’t always pushed to learn meaningfully and often exams favour rote learning,

however I hope I equipped them with the skills to go further into tertiary learning where rote

learning is no longer enough.

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<http://cmap.ihmc.us/Publications/ResearchPapers/TheoryUnderlyingConceptMaps.pdf>

[Accessed 11 April 2015].

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Figure 2. Sakurai, M., Koga, R., Tsuchida, T., Meng, X., and Fukatsu, T., 2005. Whole-mount in situ

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Appendix 1:

Lesson plan 17/04/2015 – Lesson on the genetic variation of bacteria and pathogens.

Start time: 12.55pm - Starter activity

5 minutes to settle down and get seated.

With starter activity; ask students to write down what they remember of the topics from

what they learnt.

1.00pm – Introduction to topics

10 minutes to introduce the topics.

1.10pm – Concept map explanation

15 minutes. How to construct a concept map – giving an example of an easy concept

map.

1.25pm – Construct concept maps

20 minutes. Give them A4 paper and ask them to construct concept maps on genetic

variation of bacteria and pathogens.

Run through the concept maps with students.

1.45pm – Study groups

15 minutes. Split students into groups of 4. Give each student a part of the topic to

research and create resources.

10 minutes. They then have to use these resources to explain the topic to each other.

From each group one person will come up and explain it.

10 minutes. Explanations.

2.20pm – Who wants to be a millionaire quiz

30 minutes. Who wants to be a millionaire.

Split into groups of 4 again. Each group will have a whiteboard and put answers to

questions.

2 minutes for reading and answering of each question.

2.50pm

5 minutes. Pack away and handing out of resource packs.

Resource packs contain three pages with concepts for concept maps and two further

learning pages, one on mitosis and meiosis, and one on pathogens.

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Slide 1

Revision Techniques: focussing on pathogens

and the genetic variation of bacteria.

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Slide 2

Aims and objectives

To recap these two topics

To understand concept mapping as a revision technique

To use study groups as an effective revision technique

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Slide 3

What do you remember?

How do pathogens harm humans?

How can pathogens enter the human body?

What is the difference between a virus and a bacteria?

How do antibiotics effect bacteria?

How is antibiotic resistance caused?

Slide notes

- Ask students to think about the answers to the questions for 5 minutes. - Explain when they start revision they need to write down what they remember about a

topic before continuing. - This is how students should approach revision with a clear understanding of what they

already know.

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Slide 4

What you need to know• Bacteria, viruses and fungi.

• Cause disease, by producing toxins that damage host cells.

• Viruses – made up of DNA/RNA, a protein coat and lipid envelope.

• Bacteria – are prokaryotes

• Fungal – are eukaryotes.

Slide notes

- Explain they need to then go through what they need to know from the syllabus. This is the approach they should take before beginning revision.

- As it was revision I would ask them related questions such as “how do pathogens cause disease?” before I put the slide up.

- I asked them to tell me how a prokaryote was different to a eukaryote.

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Slide 5

• Enter the body via any interface with the environment.

• Contaminated food and water- E.coli and cholera

• Airborne infections- flu, measles, tuberculosis and meningitis

• Via the skin- Tetanus and malaria

• Direct contact- HIV and STDs

Slide notes

- I asked students what famous pathogens they could think of for each pathway into the body.

- I also asked students what symptoms they knew for each disease. - We also discussed the symptoms of meningitis.

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Slide 6

Bacteria and antibiotics

• Antibiotics only affect bacteria

• They don’t affect host cells

• Cause death of bacteria via many pathways

• Prevent cell walls from forming causing osmotic lysis

Slide notes

- Asked students what osmotic lysis was, and to explain how it would cause cell death.

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Slide 7

Antibiotic resistance

• Bacteria become resistant to antibiotics when there is a mutation in the DNA

• If it is adaptive it is selected for

• It can be passed on via horizontal or vertical transmission

• MRSA

Slide notes

- I asked students to tell me the difference between horizontal and vertical gene transmission.

- I asked students to tell me what MRSA was and why it is such a big problem.

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Slide 8

Concept maps

• To tie together information in a meaningful way.

• Concepts are linked together by words, generally verbs.

• Try to really think about how concepts relate to each other.

• On an A3 piece of paper create a concept map, use pictures and colours to make it memorable.

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Slide 9

Slide notes

- Explain to students that the concept map starts at DNA. Get them to take some time to look at how the concept map is constructed.

- Make sure they pay attention to the joining words on the arrows.

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Slide 10

Virus Bacteria Disease Digestive tract

Fungal E.coli Infection Cholera

Gas exchange Antibiotics Cells HIV

Cells Toxins Protein coat MRSA

Prokaryote Lipid envelope Cell wall

Narrow spectrum Eukaryote Osmotic lysis

Selection pressure Broad spectrum

Mutations Resistant Horizontal gene transfer

Vertical gene transfer

Slide notes

- Ask students to construct a concept map using these concepts.

- Make it clear that they can use concepts more than once or not at all. They can also use

their own concepts.

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Slide 11

Slide notes

- Go through the example with them. Ask them how it is different to theirs.

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Slide 12

Study groups

• Study groups are a really good way to revise!

• In groups of 4 you will be given a section of this topic to research

• You will then explain it to the rest of your group

• Try and make it as interesting as possible, draw a poster with pictures, tell a story, make them act it out – anything!

Slide notes

- Give each member of the group a different set of questions from the study group sheet

(see page 30).

- Make sure to give lots of examples of how they could present the topics to the other

students ie. Drawings, a story, acting it out.

- Get students to use their revision notes and textbooks to find the information.

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Explain antibiotic resistance:

How does it occur?

What problems can this cause?

How does it relate to evolution?

Explain what viruses are:

What are they made of?

How do they cause infections?

How can they be treated?

Explain how antibiotics destroy bacteria:

What are the different ways antibiotics destroy bacteria?

Why don’t they harm human cells?

Why don’t they work on viruses?

Explain how pathogens enter the body:

What are the different ways pathogens enter the body?

What are some famous pathogens and their symptoms?

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Slide 13

A. They cause virusesB. They stunt organisms

growth

C. They destroy tissue and produce toxins

D. They cause red tides

How do bacteria cause disease?

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Slide 14

A. Viral infections B. Binary fission

C. Fungal infections D. Bacterial resistance

Overuse and improper use of antibiotics may cause:

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Slide 15

A. Neither bacterial nor viral infections

B. Viral infections only

C. Bacterial infections onlyD. Bacterial and viral

infections

The use of antibiotics is an effective treatment for:

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Slide 16

A. Binary fission B. Budding

C. Spore formation D. Parthenogenesis

How do bacteria reproduce asexually?

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Slide 17

A. An antibiotic B. A virus

C. A vaccine D. Water

A chemical that can kill bacteria without harming the human body is:

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Slide 18

A. Conjugate with other viruses

B. Invade a host cell

C. Manufacture extra food D. Remain hidden

In order to multiply, a virus must:

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Slide 19

A. Immune B. Endocrine

C. Reproductive D. Digestive

HIV virus affects what system of the body?

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Slide 20

A. Flagella B. Cell wall

C. Pilli D. Capsule

During conjugation how do bacteria exchange information?

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Slide 21

A. A nucleoid region B. An endospore

C. A nucleus D. A heterospore

Bacteria normally contain their genome in:

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Slide 22

A. Eukaryotes generally are larger than bacteria

B. Bacteria lack internal compartmentalisation

C. Both types of organisms reproduce by mitosis

D. Bacteria are single-celled

Which one of the following statements is false about bacteria and eukaryotes?

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Slide 23

A. Flagella B. Pilli

C. Capsule D. Rough ER

Which of the following does a prokaryotic cell not contain?

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Slide 24

A. Lentivirus B. Retrovirus

C. Adenovirus D. Adeno-associated virus

What type of virus is HIV?

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Slide 25

A. E.coli B. Salmonella

C. V. cholerae D. C.botulinum

Which of these pathogens does not affect the digestive system?

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Slide 26

A. Photoautotrophs B. Chemoautotrophs

C. Detrtivores D. Heterotrophs

Organisms that obtain their energy by oxidising inorganic chemical sources are called:

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Slide 27

A. Mycosis B. Sepsis

C. Campylobacter D. Encephalitus

What is the term used for an infection caused by a fungal parasite?

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GENES

Locus DNA Base sequence Polypeptides Mutation

Alleles Triplet Amino acid Amino acid sequence

Introns Non-functional proteins Base sequence differences

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ENZYMES

Protein Denature Active site Specific pH Optimum

Temperature Inactive Activation energy Saturation Inhibitors

Competitive Non-competitive Enzyme concentration Rate of reaction

Substrate concentration Enzyme-substrate complex

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CELL REPRODUCTION

Meiosis Meiosis 1 Meiosis 2 Chromatin Chromosome

Prophase 1 Homologous chromosomes Crossing over

Sister Chromatids Tetrads Metaphase 1 Anaphase 1

Independent assortment Telophase 1 Cytokinesis Prophase 2

Chromosomes Metaphase 2 Anaphase 2 Telophase 2

Genetic variation Gametes Mitosis Growth and repair

Interphase G1 G2 S-phase Growth

DNA synthesis Prophase Metaphase Anaphase Telophase

Cytokinesis Mitotic spindle Centromere Microtubules

Two daughter cells Four non-identical cells

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Further your learning HIV – Will science ever find a cure?

Human immune- odeficiency virus (HIV), the virus that causes AIDS, targets specific cells in the immune system, known as T cells [2].

HIV is a retrovirus, carrying the enzyme reverse transcriptase. Once the virus enters the host cell it uses this enzyme to make viral DNA from viral RNA. The viral DNA is incorporated into the hosts own DNA, allowing the production of thousands of new viruses. This process causes the weakening of the immune system [3] that leaves sufferers vulnerable to other infections such as tuberculosis and malaria. The main issue in the treatment of HIV is the fast evolution of the viruses’ surface proteins meaning that anti-viral drugs lose effectiveness fast [2].

However there have been recent developments by scientists [7], who have discovered an antibody (3BNC117) that reduces levels of the virus in humans. In clinical trials, 29 participants were tested, 8 of them were given the highest dose of 3BNC117, and this was found to reduce virus levels by between 8 and 250 times. However there are still issues; this treatment is incredibly expensive, with one course of antibodies costing thousands of dollars and most sufferers live in poorer countries. Also the rapid evolution of HIV still effects this treatment with patients who received the highest dose of antibody finding it was 80% less effective after 28 days. Scientists suggest that this new antibody will need to be used in conjunction with other antibodies to combat this problem.

The Ebola epidemic - here to stay?

The infamous Ebola virus has caused over 10,000 deaths in 2014 alone [4]. The recent outbreak was caused by the Zaire species [9]. With a fatality percentage of 69%, it is thought to be the most virulent species, begging urgent research attention.

The Ebola virus owes its virulence to the mechanisms it uses to disarm the immune response. The virus inhibits cells that signal for the T-cells to destroy them before infection spreads. With no T-cell activation, there is no activation of antibodies. From here the virus travels in the blood to the organs, and causes macrophages to release coagulants to clot the blood causing haemorrhaging [11].

Current treatments for Ebola include blood transfusions from Ebola survivors, but research is also looking into two vaccines that may be able to stop the disease [9]. Research also shows that survival may be down to genetics, as survivors have more activated T-cells due to possessing a different gene variant [11]. Much research is also going into making the diagnosis of Ebola easier with the creation of a rapid diagnostic kit.

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1.

Bacteria and the dinosaurs

Bacteria are important in a process called exceptional preservation, where structures like skin, feathers and organs which are not normally preserved are fossilised [6]. This has led to major discoveries such as theropod dinosaurs were actually covered in feathers.

The process of exceptional preservation occurs when an organism dies in environments with certain characteristics, for example, places where scavengers can’t eat the carcasses and anoxic environments so that bacteria can’t degrade it. These tend to be lakes or ash falls from volcanoes. However microbial mats have also been found to allow exceptional preservation.

In Grube Messel sit in Germany there are fossils which are fully articulated, and some soft tissue even remains. When a PhD student examined the fossils with a electron microscope, they found the fossil to be made up of rod and spherical microbes. From this they deduced that there was a layer of bacteria on the underside of the body, which had become petrified when the carcass landed on them. These bacteria were then cemented in place by organic material from plants. These sorts of discoveries can tell us lots about the past, and evolution.

Can bacteria really control behaviour?

Is it crazy to think that tiny single-celled bacteria could control an organism’s behaviour? Well they do!

Weird Wolbacia

Wolbacia bacteria which live inside the reproductive tissues of Arthropods are famous for being able to change their hosts’ physiology to increase their chance of being passed on to offspring [15]. The Wolbacia bacteria are only passed on via female hosts, this leads them to change their hosts to make sure that they maximise their population. In parasitic wasps Wolbacia induce parthenogenesis in hosts. This means that offspring can form from unfertilised eggs; this guarantees that the bacteria will be present in the offspring. It has also been seen in crustaceans that Wolbacia causes the feminization of genetic males. The bacterium converts males into reproductively competent females. All of these mechanisms give a selection advantage to the bacterium that has led to them being widespread throughout the animal kingdom.

Bizarre Buchnera

Buchnera are round-shaped bacteria which live in specific cells called bacteriocytes in most aphid species [13]. These bacteria are maternally transmitted to eggs, and neither the aphid nor buchnera can reproduce alone. These bacteria provision the aphids with essential amino acids [5], which are not present in the sticky phloem sap on which the aphids feed. In return the bacteria live within the aphid.

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The future of cancer research

Cancer is caused by the uncontrolled division of cells, [3] this is due to a malfunction in mitosis. The University of Bath researchers have been looking at ways to stop cells dividing. They have discovered a target protein, RASSF7, which is essential for building microtubules. Without microtubules cell division doesn’t occur properly [14].

The University of Wisconsin has also been researching ways to stop cancer [8]. They have found a new form of cell division in humans known as klerokinesis. They believe it is a natural back up mechanism to faulty cell division, which prevents calls causing cancer. By placing two nuclei in the cells they found the cells split without mitosis, and normally during interphase. If scientists could find a way to carry out this cell division it could help stop cancer.

Cancer can be caused by mitotic spindles failing to divide genetic material equally. At Warwick Medical School [10], researchers have discovered a protein complex called TACC3-ch-TOG-clathrin which holds the spindles microtubules together. Some anti-cancer drugs inhibit mitotic spindles from forming, but don’t distinguish between normal and cancerous cells. Recent studies have found that if the TACC3 protein is removed then spindles don’t form. By targeting the mitotic spindle protein complex, an effective anti-cancer drug could be produced.

Further your learning New discoveries in meiosis

Meiosis is incredibly important for generating genetic variation via crossing over and independent assortment. However faults in these processes can lead to birth defects.

A PhD student at Cornell University [12] have found a protein, Mlh3, which checks the quality of cell’s DNA during replication, repairing it if necessary. It also allows communication between overlapping chromosomes during crossing over. If this process goes wrong the chromosomes won’t pull apart, causing birth defects. Now that the protein controlling this is found research can be aimed at reducing faults.

New York University [1] have also been researching meiosis. During meiosis DNA replicates and is then recombined to give genetic variation. Disruption to this process causes birth defects. They have established two enzymes necessary for meiosis, Mec1 and DDK.

Mec1 senses when chromosomes are being replicated and sends a molecular “wait” signal to the second enzyme DDK, which coordinates chromosome reshuffling. Understanding this process is the first step to establishing how to stop birth defects.

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Appendix references:

Amos, J., 2003. Fossil of Archaeopterix. [photograph] Available at:

<http://www.sciencephoto.com/media/172092/view> [Accessed 4 April 2015].

Boyle, M., and Senior, K., 2008. Biology. 3rd ed. London: Collins.

Campbell, N., and Reece, J., 2011. Campbell Biology. 9th ed. San Francisco: Benjamin Cummings.

Davidson, M., 2013. Human Immunodeficiency Virus (HIV) Anatomy. [image] Available at:

<http://micro.magnet.fsu.edu/cells/viruses/hivvirus.html> [Accessed 4 April 2015].

Fox, C., 1987. Cancer cells. [photograph] Available at:

<https://visualsonline.cancer.gov/details.cfm?imageid=2306> [Accessed 4 April 2015].

Gerber, G., 2011. Small Parasitic Wasp. [photograph]. Available

at:<http://bugguide.net/node/view/512635/bgimage> [Accessed 4 April 2015].

Meiosis interphase microscope. [Photograph] Available at: <http://imgkid.com/meiosis-

interphase-microscope.shtml> [Accessed 4 April 2015].

Mitosis under microscope. [Photograph] <Available at: http://imgkid.com/mitosis-under-

microscope.shtml> [Accessed 4 April 2015].

Novak, J., and Cañas, A., 2006. The Theory Underlying Concept Maps and How to Construct them

[pdf]. Institute for Human and Machine Cognition. Available at:

<http://cmap.ihmc.us/Publications/ResearchPapers/TheoryUnderlyingConceptMaps.pdf>

[Accessed 11 April 2015].

Figure 2. Sakurai, M., Koga, R., Tsuchida, T., Meng, X., and Fukatsu, T., 2005. Whole-mount in situ

hybridisation of aphid embryos targeting Rickettsia and Buchnera. [microscope image]. Applied

and Environmental Microbiology. 71(7), 4069 – 4075.

Timmer, J., 2014. The ebola virus, magnified 108,000 times. [photograph] Available at:

<http://arstechnica.com/science/2014/11/understanding-the-ebola-virus/> [Accessed 4 April

2015].

[1] Blitzblau, H., and Hochwagen, A., 2013. ATR/Mec1 prevents lethal meiotic recombination

initiation on partially replicated chromosomes in budding yeast. Elife. 2: e00844.

[2] Boyle, M., and Senior, K., 2008. Biology. 3rd ed. London: Collins.

[3] Campbell, N., and Reece, J., 2011. Campbell Biology. 9th ed. San Francisco: Benjamin

Cummings.

[4] Centers for Disease Control and Prevention, 2014. 2014 Ebola Outbreak in West Africa –

Case counts [online] Accessed at <http://www.cdc.gov/vhf/ebola/outbreaks/2014-west-

africa/case-counts.html> [Accessed 4 April 2015].

[5] Douglas, A., 1998. Nutritional interactions in insect-microbial symbioses: aphids and their

symbiotic bacteria Buchnera. Annual Review of Entomology. 43, 17-37.

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[6] Franzen, J., 1985. Exceptional preservation of Eocene vertebrates in the lake deposit of

Grube Messel (West Germany). Philosophical Transactions of the Royal Society of London. 311,

181-186.

[7] Hayden, E. 2015. Antibody shows promise as treatment for HIV. Nature News, [online]

Available at: <http://www.nature.com/news/antibody-shows-promise-as-treatment-for-hiv-

1.17260> [Accessed 4 April 2015].

[8] Land, D., 2012. New form of cell division found. University of Wisconsin-Madison News.

[online] Available at: <http://www.news.wisc.edu/21364> [Accessed 4 April 2015].

[9] Nice, K., 2014. Ebola: What is Ebola, outbreaks and current research. AbD Serotec, A Bio-Rad

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[Accessed 4 April 2015].

[10] Scowcroft, H., 2013. ‘Mitotic spindles’ could help develop better chemo drugs. Cancer

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[11] Servick, K., 2013. What does Ebola actually do? Science Insider, [online] Available at:

<http://news.sciencemag.org/health/2014/08/what-does-ebola-actually-

do?intcmp=collection-ebola> [Accessed 4 April 2015].

[12] Shackford, S., 2014. Grad student may have found ‘missing link’ of meiosis. Cornell Chronicle,

[online] Available at: <http://www.news.cornell.edu/stories/2014/03/grad-student-may-have-

found-missing-link-meiosis> [Accessed 4 April 2015].

[13] Shigenobu, S., Watanabe, H., Hattori, M., Sakaki, Y., and Ishikawa, H., 2000. Genome

sequence of the endocellular bacterial symbiont of aphids Buchnera sp. Nature. 407, 81-86.

[14] University of Bath. 2008. Mitosis Gets Harder Thanks To New Gene Discovery. ScienceDaily.

[online] Available at: <www.sciencedaily.com/releases/2008/04/080403104400.htm>

[Accessed 4 April 2015].

[15] Werren, J., 1997. Biology of Wolbacia. Annual Review of Entomology. 42, 587-609.