UNIT 7: BIODIVERSITY. THE LEAST COMPLEX LIVING THINGS

1. What is the origin of biodiversity?

2. Classifying biodiversity

3. The simplest living things: bacteria

4. Algae and protozoan

5. Fungi

1. WHAT IS THE ORIGIN OF BIODIVERSITY?

BIODIVERSITY: refers to the many species of living beings that live on Earth.

BIOLOGICAL EVOLUTION: process of gradual change in living beings

that have survived in different environments.

THEORY OF EVOLUTION: was formulated by Charles Darwin:

“a new species originates from a pre-existing one”.

Species that do not envolve or adapt to new environmental conditions

become extinct: NATURAL SELECTION.

VOCABULARY: biodiversity, biological evolution, natural selection, overcome (superar), adaptations, allow, fossil, provide.

Human evolution Small dinosaurs Bird

VÍDEO ABOUT NATURAL SELECTION

https://www.youtube.com/watch?v=0SCjhI86grU

Fossils Remains of living things that have been transformed by a

long process called fossilisation.

Fossils are found in sedimentary rocks and show us what organisms were originally like and how they changed over time.

Fossils provide us with valuable clues about the evolution and transformation of living beings

Fossilisation

Activity. Answer the questions:

a) Which types of cell was the first cell?

b) Which type of living things, according to the number of cells, were the first living

beings?

c) Who was the British scientist that proposed the theory of evolution?

d) What does theory of evolution say?

e) What are fossils made of?

f) In which type of rocks can we find fossils?

g) What information do fossils provide us?

h) When did first land plants emerge? And first flowering plants?

2. CLASSIFYING BIODIVERSITY

TAXONOMY: science of classifying living beings.

Currently, all organisms are grouped into five kingdoms

Prokaryotic

According to the type of cell

Eukaryotic

According to the number of cells

Unicellular Multicellular

According to the type of nutrition

LIVING BEINGS

Autotrophic Heterotrophic

ANIMALIA KINGDOM

PROTISTA* KINGDOM

PLANTAE KINGDOM

FUNGI* KINGDOM

MONERA KINGDOM

Bacteria Protozoa (unicellular)

Algae (uni and multicellular) Yeasts (unicellular)

Mushrooms and moulds (multicellular)

Plants Animals

¿POR QUÉ ES IMPORTANTE PROTEGER LA BIODIVERSIDAD?

¿CÓMO SE NOMBRAN LOS SERES VIVOS?

Todos los seres vivos presentan dos nombres:

1. Nombre vulgar, que es el nombre de un ser vivo característico de un país, ciudad o pueblo. Ejemplo: tomillo, liebre…

2. Nombre científico, que es el nombre que presenta cada ser vivo y es común a todos los países. Fue propuesto por Carl Von Linneo y constituye la NOMECLATURA BINOMIAL. El nombre científico de un ser vivo está formado por dos palabras en latín y en cursiva:

- la primera palabra se escribe en mayúscula (la primera letra) y hace referencia al género.

- la segunda palabra se escribe en minúscula y hace referencia a la especie.

Ejemplo: Lepus europaeus (liebre europea), Lepus es el género y europaeus la especie.

3. THE SIMPLEST LIVING THINGS: BACTERIA

Bacteria belong to the Monera Kingdom, they are unicellular organisms with a prokaryotic cell structure.

The structure of bacteria is very simple:

1. Capsule (optional)

2. Cell wall

3. CELL MEMBRANE

4. CYTOPLASM

5. Ribosomes

6. GENETIC MATERIAL (DNA)

7. Flagellum

CLASSIFICATION OF BACTERIA

According to their shape According to their nutrition

Cocci (cocos) Spherical shape

Bacilli (bacilos) Elongated shape

Spirilla (espirilos) Spiral shape

Vibrio (vibrios) Comma - shaped

Bacteria de la meningitis

Bacteria de la salmonelosis

Bacteria de la sífilis

Bacteria del cólera

Autotrophic (autótrofa)

According to the origin to their food

Saprophytes (saprófitas)

Mutualistic (mutualistas)

Parasitic (parásitos)

They make their own food They obtain their food from outside

They live on decomposing organic material

They work together with other organisms for mutual benefit

They can cause diseases in other living beings

EXAMPLES: dental plaque and bacteria living in soil

EXAMPLES: intestinal flora

EXAMPLES: bacteria de la meningitis,

bacteria de la salmonelosis, bacteria del cólera…

Heterotrophic (heterótrofa)

Bacteria de la meningitis: Neisseria menigitidis (meningococo)

Bacteria del cólera: Vibrio cholerae

Bacteria de la salmonelosis: Salmonella enterica

Bacteria de la sífilis: Treponema pallidum

BACTERIA

Benefits Damage

1. Intestinal or gut flora - they produce substances that act

against bacteria that cause illnesses

- they produce vitamins B and K

- they activate defences

2. Making dairy products: yogurt and cheese

Causing diseases Examples: meningitis and

salmonelosis.

Some diseases are produced by

viruses: measles, AIDS.

Antibiotics only attack bacteria so they should not be taken to treat

an illness caused by virus

4. ALGAE AND PROTOZOA

Protozoa

Paramecium Protozoan with many cilia

surrounding

Amoeba Protozoan with pseudopods

Leishmania Protozoan with flagellum

Plasmodium Immobile protozoan

Unicellular algae

Unicellular flagellate algae Diatomeas

Multicellular algae (Green, red and brown algae)

Activities 12 and 13 on page 72

5. FUNGI VOCABULARY: skin, bread, wine, beer, filamentous structure, hyphae, strip of cells, mycelium, spore, bark of trees, manufacture (fabricar).

Moulds. Penicillium Yeasts

Mushrooms

Activity 16 on page 73

Activity. Where do lichens live?

Activities on page 74