Citation preview
Essential Questions 4
Lesson 2.1: Genes 5
Objectives Warm-up Learn about It Key
Points Web Links Check Your Understanding
Challenge Yourself
5 5 6
Lesson 2.2: Laws of Heredity and the Punnett Square
14
Objectives Warm-up Learn about It Key
Points Web Links Check Your Understanding
Challenge Yourself
14 14 15 27 27 28
29
Lesson 2.3: Non-Mendelian Inheritance 30
Objectives Warm-up Learn about It Key
Points Web Links Check Your Understanding
Challenge Yourself
30 30 31 40 40 40
42
Lesson 2.4: Multiple Genes 43
Objectives Warm-up Learn about It Key
Points Web Links Check Your Understanding
Challenge Yourself
43 43 44 46 46 46
47
Laboratory Activity 48
Performance Task 50
Self Check 52
Key Words 52
Wrap up 54
At the end of this unit, you should be able to answer the following
questions. How are genes related to heredity? Why are
genes important to human beings and other living organisms?
How can the structure of genes affect the amino acid
sequences? How were the pea plants used to generate the
Mendelian laws? How are Punnett squares used to solve genetic
problems? How did non-Mendelian patterns of inheritance
occur? How are Mendelian laws different from non-Mendelian
inheritance? Why is the environment a significant factor for
traits considered under
multiple genes?
The deoxyribonucleic acid (or DNA) is the molecule responsible for
carrying
the genetic blueprint for the general identity
of living organisms.
During meiosis, DNA is replicated, and the recombination between
pairs of
homologous chromosomes happen. Meiosis allows
the exchange of genetic
materials between chromosomes, leading to
variations in the genetic
makeup of the resulting haploid daughter
cells. These haploid daughter cells
are the gametes or
sex cells.
Have you ever observed yourself in a mirror and
wondered why you are the way
you are? Or maybe, you have been fascinated at times, at how
you are almost a
carbon copy of your father, your mother, or a relative? Most of the
times, people
will tell
you that you have the same traits as your parents because they
passed their
genes to
you. What are genes, why are they important, and how do they
affect
you?
The Folk Hunt In this activity, you
will roam around the room
and guess whose parents are
indicated in the picture.
Materials:
picture of parents notebook
Procedure:
1. Have tables in a circle formation. 2. Take note of the
letter that is assigned to you by your teacher. 3. Make sure
to keep the photos of your parents hidden from your
classmates
and indicate your assigned letter.
4. Randomly put the picture of your parents in different
tables. 5. For five minutes, you will roam around the room
and guess whose parents
are placed on the tables. Remember to indicate the letter for each
picture
that you are
guessing.
Guide Questions:
1. How were you able to identify the parents of your classmates
without
meeting them?
2. What are the things that you have considered to accomplish the
activity?
The gene consists of a specific nucleotide sequence and has a
definite position in a
given chromosome. This particular sequence codes for a specific
protein for
phenotype expression. A gene has
four major units.
Exons are the coding regions, which are translated to a specific
sequence of
amino acids
Introns are the non-coding regions, which do not specify any amino
acid
sequence for protein synthesis.
The promoter region is the regulatory sequence that regulates
the
activation of genes, which also determines when and where
the protein
should be synthesized. The CAT and TATA boxes
are components that are
found in the promoter
region.
Fig. 4. Chromosomes, DNA, and genes
Do not confuse chromosome with chromatin and chromatid. The
chromosome is
just the condensed version of
chromatin. It means that chromatin is only evident
during prophase while chromosome is evident during
metaphase. The one that you
can see in the
microscope is chromosome, not chromatin. On the other hand,
the
chromatid is one version of the
duplicated chromosome. Since there are 46
chromosomes in humans, the number of chromatids is 92. To help you
remember
the difference, bear in mind
that a chromosome is also the same as sister
chromatids.
Fig. 5. Difference of chromatin, chromatid, and
chromosome.
Fig. 6. Chromatin and condensed chromosome
structure
The deoxyribonucleic acid (or DNA) is considered the blueprint of
life. A gene is a segment of the DNA that serves as a unit of
heredity.
In eukaryotes, the genetic material is all stored within the
nucleus
bound by the nuclear membrane. In prokaryotes,
the genetic material
is suspended in the cytoplasm known as
the nucleoid region.
The DNA wrapped in histones is termed as the
chromosomes. The chromatid is one version of the
duplicated chromosome. The chromatin is just the uncondensed
counterpart of chromosomes. A genotype is a set of genes that
influence and control the expression of
biological traits. A phenotypes is an observable trait
expressed in an individual. A gene has four major units:
exons, introns, promoter region, and enhancer
region.
A. Arrange the following levels of organization in the genetic
materials within
organisms. Write your answer inside the stacked Venn below.
B. Match the following parts of a gene with their respective
function. 1. Enhancer region a. coding region
of the gene
2. Promoter region b. non-coding region of the gene 3.
Introns c. regulates the activation of a gene 4. Extrons d.
interacts to the transcription factor
5. Gene e. controls phenotypes
phosphate group
sugar group
4.
9.
Read the following questions carefully. Then, answer
briefly.
With his work on the pea plant, an Austrian monk,
Gregor Mendel, discovered the
basic principles of inheritance. He spent a lot of his time
crossing pea plants and
noticed some patterns of inheritance of traits coming from one
generation to the
next. With his
experiments, he was able to establish concepts known today as
the
laws of heredity. What are these
laws of heredity?
Who Am I? Through this activity you will get to know
yourself better through your classmates
eyes. Materials:
bond paper pen clear tape
Procedure:
1. Using clear tape, place a whole sheet of paper on your back.
(You may ask
your classmates to
help you with this.)
2. Try to scan the faces and physical attributes of your
classmates. 3. On the papers placed on your classmates’
backs, write a specific physical
attribute for each of them. (Remember you are not allowed to give
hurtful
remarks.)
5. Remove the papers from your backs after the activity. 6.
Compare the answers on your paper with a seatmate and make
conclusions
per pair by answering the following questions below:
Guide Questions:
1. Looking at your papers, were there traits that are similar? What
are those?
Infer some reasons as to why it
is possible.
2. What are the traits that are different? List them down. What do
you think
contributes to your
differences?
3. How can these similarities and differences benefit
us?
with the terms below so that so you could understand the experiment
very well.
Parental generation (P generation) – the initial generation.
First filial generation (F1 generation) – the first set of
offsprings from parent
generation. The F1 generation can reproduce to make the F2
generation and
so on.
Pure-bred plants - these refer to plants that “always” produce an
offspring
with identical trait as the parent for
many generations. For example, a parent
plant with a tall trait crossed by a plant with the same trait will
produce a
100%
offspring with the tall trait.
Self-fertilization – some plants can fertilize by themselves. It is
possible
because some plants such as pea plants possess
both reproductive organs
(stamen and pistil)
Mendel did the pea plant experiment by first crossing two
pure-bred plants. In
Fig. 7., the
purebred purple flower is crossed by a purebred white
flower.
Fig. 8. The process on how Mendel did the pea plant
experiment
two flowers using a paintbrush. He planted the seeds from the
resulting matured
pod. If the blending
theory of inheritance is correct, the offspring should be a
pea
plant with a color in
between the purple and white since the trait is mixed.
However, the result of Mendel’s
experiment after the cross, also called the F1
generation, is a 100% purple flower. As a result, this
experiment disproved the
former blending
theory of inheritance. The resulting plants in the F1
generation were allowed to self-fertilize. If the
blending theory of inheritance is correct, the result
should be 100% purple flowers
since the
parent is just one which is the purple flower. However, the result
is 75%
purple and
25% white flower. This result is another proof that the blending
theory
of inheritance is
incorrect.
Fig. 9. Result of the pea plant experiment
A dominant trait exists when a dominant allele masks the expression
of the
recessive allele, if present.
Dominant alleles are often denoted by two
uppercase
letters or one uppercase, one lowercase letter. For example, tall
is
dominant for the height trait. Therefore, it
is represented by TT or Tt.
A recessive trait exists if the dominant allele is not present.
This trait has a
pair of
recessive alleles. It is written in small letters. For example,
short is
dominant for the height
trait. Therefore, it is represented by tt.
In his pea plant experiment, Mendel found out the following
dominant and
recessive traits of pea plants.
The law of dominance states that a pure line (homozygous) dominant
trait
crossed with a recessive trait will result in
the expression of the dominant
trait for
all the resulting offsprings. It is shown in the F1 generation of
Mendel’s
pea plant
experiment. Purebred tall crossed by short pea plant result to
the
expression of the dominant trait which
is tall in all the resulting offsprings.
Table 1. Pairing of alleles for genes controlling certain
traits.
Genotype symbol Genotype classification
Phenotype*
TT homozygous dominant tall
Tt heterozygous dominant tall
tt homozygous recessive short
* assuming that “t” is the gene that controls the height
phenotype
Fig. 11. Resulting genes in each gametes after
meiosis.
During sex cell formation, two alleles that code for a
certain trait separate from one
another to form sex cells that contain only one gene of the
pair. During fertilization,
the offspring tend to get one genetic allele from each
parent, the egg and the
sperm cells. The cell with the combined alleles from both parents
now forms the
offspring.
Law of Independent Assortment With Mendel’s
work on several cross breeds of pea plants, he observed that
the
height of the plant (T), color
(Y) and shape (R) of the seeds did not affect the
inheritance of one
another. A plant which is tall does not automatically mean
that
the plant will have yellow pods,
nor did yellow seeds to have round shape. Mendel
derived a conclusion that the different
traits are inherited independently. The law of
independent assortment explains that genes responsible for
the
expression of different traits are sorted
independently from each other. This
means that the
inheritance of each trait is highly independent of the inheritance
of
other traits.
Fig. 13. Independent inheritance of pod shape (round = R;
wrinkled = r) and
Color (yellow = Y; green = y) in pea plants.
Fig. 13 shows that different genes controlling for different traits
such as pod shape
and pod color are
distributed in each gamete independently. One trait does not
affect the inheritance of the other.
The three laws of Mendel explain how meiosis works.
If you have a deep
understanding on
meiosis, the laws of Mendel are not a problem to you. Fig.
14.
summarizes the three laws
using the meiosis model.
Fig. 14. Meiosis and the laws of Mendel
A Punnett square is a graphical representation for predicting all
possible resulting
genotype combination of a
specific cross or breeding experiment. To
predict the resulting genotype combination, follow the steps
below. Step 1 Draw a Punnett square by setting up a grid of
perpendicular lines. Step 2 Place the genotype of one parent
on the top. Step 3 Place the genotype of the other parent
down the left side. Step 4 Fill the spaces at the center by
copying the letters on the row and
column headings across or down into the empty squares.
Example 1 One dog is heterozygous for black haired trait
(Bb), and its partner is homozygous
white-haired trait (bb). Using the Punnett square, determine
the ratio for the
phenotype of their
offspring. Solution Step 1 Identify the
genotype both parents.
heterozygous black-haired traits × homozygous white-haired
traits Bb × bb
Step 2 Construct the Punnett square for the
cross.
2 Bb = Heterozygous black-haired trait 2 bb = Homozygous
white-haired trait
Let us Practice Mendel crossed red flowered pea plants with
white flowered pea plants. (Red
flowers are
dominant to white.) Both stocks of plants were homozygous.
What
color flowers will the offspring plants
have?
Example 2 A red and a white flower were crossed and it
resulted to a 0% probability for a
white color flower. Red is dominant
over white. Using the Punnett square,
determine
the possible phenotype of parents.
Solution
Step 1 Identify the genotype of the offspring. There
are two genotype RR and Rr will result to red.
Step 3 Interpret the result.
Example 3 Two individuals who are carriers of the
recessive allele for cystic fibrosis were
crossed. Determine the probability of the offspring to
inherit the said disease. Solution Step
1 Identify the genotype of both parents. Both of them are
carrier of a recessive disease. Therefore, their
genotype is heterozygous for the expression of cystic
fibrosis.
Step 3: Interpret the result. 25% chance of having the cystic
fibrosis (cc) 50% chance of to be a carrier of the disease
(Cc) 25% chance of being healthy and not carrier of the
recessive allele (CC)
Therefore, 25% of their offspring can inherit cystic
fibrosis.
Mendel proposed three laws of heredity: the law of dominance, the
law of
segregation, and the law of independent assortment. An
allele controls similar traits but exhibits different
phenotypes. A Punnett square is a graphical representation
for predicting all possible
resulting genotype combination of a specific cross or breeding
experiment.
For further information, you can check the following
links:
A. Identify which Mendelian principle is being
described below. Use A-law of
dominance, B-law of segregation, and C-law of independent
assortment. 1. It states that the recessive trait is being
masked. 2. Two alleles that code for a certain trait separate
from one another during
sex cell formation. 3. The cell with the combined alleles
from both parents forms the offspring. 4. There is a stronger
gene in heterozygous pairing. 5. The inheritance of each
trait is highly independent on the inheritance of
other traits. 6. The height of the plant (T), color (Y) and
shape (R) of the seeds had no
effect on the inheritance of one another. 7. Alleles must
segregate somewhere between the production of sex cells
and fertilization. 8. When there is a dominant homozygous
gene, the resulting offspring will
only exhibit the dominant trait. 9. In the process of
fertilization, the offspring tend to get one genetic allele
from each parent when the egg cell and the sperm cell unite.
10. Mendel derived a conclusion that the different traits are
inherited
independently. B. Determine the resulting
offspring and the percentage of the genotype based on
the parents’ alleles.
Trait Parents’ Alleles Resulting
Offspring
Percentage of the Genotype
Widow’s Peak E (widow’s peak) e (without widow’s
peak)
EE × ee
Ll × ll
DD × dd
Hh × Hh
Read the following questions carefully. Then, answer
briefly.
1. What are the differences among the Mendelian principles?
2. How do these principles help in the study of genetics? 3.
Why did Mendel choose pea plants for his experiment on
inheritance? 4. Green seed color is dominant over yellow. If
you conducted a cross between
homozygous yellow plants (gg) and heterozygous green plants (Gg),
what are
the resulting genotypic and phenotypic ratios
of the offspring?
pen and paper Procedure:
1. Find a partner. 2. Observe the flowers shown. List
down your observations on a piece of
paper. 3. After 2 to 3 minutes, exchange papers with your
partner and identify the
similar answers from your observations. Guide
Questions:
1. What are your observations from the three pictures below ?
2. What are the possible reasons for your observation? Identify
their
advantages.
Shown below is a cross through a Punnett square that exhibits the
equal chances of
having a
female and a male offspring.
X Y
When the trait is linked to the X chromosome, it is
called X-linked trait while if the
trait is linked to the Y chromosome, it
is called Y-linked trait. The x-linked trait is
most common in males than females. It is because the males
only have one X chromosome.
Therefore, if a trait is linked to their single X
chromosome, they will already exhibit
it in their phenotype. In the case of females,
it is less common since females have two X
chromosome. It means that before the
female express the X-linked trait, the trait should
be linked in both X chromosomes.
If
only one of the chromosome is affected, the female is just a
carrier of the trait but
does not possess it in their phenotype. As a
whole, the X-linked trait is more
common in males because they have 1/2 or 50% chance for them
to express the
trait while
females only have 1/3 or 33.3% chance of acquiring the
trait. Table 2. Possible color blindness
genotypes and phenotypes of males and females.
Female Male
XCX Carrier female XCY Colorblind
male
XCXC Colorblind female
An example of a recessive x-linked trait in humans is hemophilia
and
colorblindness. Hemophilia is a genetic
disorder that disallows the body to make
blood
clots. Hence, bleeding will not stop. On the other hand, color
blindness is a
trait
wherein a person cannot distinguish colors properly. Both traits
are found on
the X chromosome, not on the Y.
Table 2 shows the possible color blindness
genotypes and phenotypes of males and females. Same
genotypes could be used if
dealing with the
hemophilia trait. Just change the letter ‘C’ to ‘H’ to avoid
confusion. The Y-linked trait is only common in males
since only males have Y chromosome.
Therefore, if the father possessed the Y-linked trait, all
the male offsprings will
acquire the trait.
The female offspring will never acquire the trait. An example is
the
hypertrichosis pinnae
auris trait. This trait is characterized by having a hairy
ear. Sex-Influenced Trait Sex-influenced
trait is an autosomal trait. As opposed to sex-linked trait,
sex-influenced trait is not located on the sex chromosomes.
However, the sex of a
person
influences the trait. It means that sex-influenced trait can be
found in
both sexes but expressed more in
one sex than the other. An example of this is
the baldness trait. Baldness is more
common in males than females because they
have 2/3 or 66.7 % chance of acquiring the trait. As shown
in Table 3, the possibility
of a male to acquire the trait is 2 (XBYB and
XBXb) out of 3 genotypes. On the other
hand, females only have
1/3 or 33.3 % chance of acquiring the trait. It is because
the possibility of a
female to acquire the trait is 1 (XBXB) out of 3 genotypes.
Table 3. Possible baldness genotypes and phenotypes of males
and females
Female Male
XBXB Bald XBYB Bald
XBXb Non-bald (normal) XBYb
Bald
XbXb Non-bald (normal) XbYb Non-bald
(normal)
Sex-Limited Trait Sex-limited trait is also an
autosomal trait. Similar to sex-influenced trait, the sex
of a person has something to do with the
expression of the trait. It means that
sex-limited traits could be found in both
sexes but only one sex expresses it
on their phenotype. An example of this trait is the
lactation trait. This trait is both
Copyright © 2018 Quipper Limited 35
found in males and females. However, only the females express it on
their
phenotype. Table 4 shows that the trait
is found in male genotypes but any
genotype could not express the lactation trait in the
phenotype of males. Table 4. Possible Lactation
Genotypes and Phenotypes of Males and Females
Female Male
Genotypes Phenotypes Genotypes
Phenotypes
XLXl Lactating XLYl Not
lactating
XLXl Lactating XLYl Not
lactating
XlXl Not lactating XlYl Not
lactating
Multiple Alleles In some traits, a certain gene can
have more than a pair of alleles that controls the
expression of traits.
This is evident in the patterns of inheritance in human blood
type. The ABO blood type has three
alleles (A, B, and O) governing this
characteristic.
Table 5. Blood types and their corresponding genotypes
Blood Type Genotype
As shown in Table 5, genetic inheritance of blood type works in
this manner:
Both the A and B are dominant alleles over O. Blood type O
can be expressed by homozygous recessive, OO. Blood type A
can have a homozygous dominant AA or heterozygous
dominant AO
Blood type B can have homozygous dominant BB or heterozygous
dominant BO.
Blood type AB has codominant AB alleles because both are
expressed
equally in the phenotype of the individual
with heterozygous gene.
Fig. 18. Multiple alleles controlling human blood type
inheritance.
Example 1 Cross two pink snapdragons. Using the
Punnett square, determine the percentage
for the pink
genotypic and phenotypic traits.
Solution Step 1 Identify the genotype of
both parents.
heterozygous pink × heterozygous pink Rr × Rr
Step 3 Interpret the results.
2 Rr = Heterozygous pink snapdragons 1 rr = Homozygous white
snapdragons 1 RR = Homozygous red snapdragons
The percentage for pink phenotype and genotype is both
50%.
Let us Practice What is the result of a cross between a pink
snapdragon and a white snapdragon? Follow the same concept
above.
Example 2 A woman who is a carrier of colorblindness
trait marries a man who is colorblind (a
recessive sex-linked trait). What are the
chances of them having a son or daughter
who is colorblind? Using the Punnett square, determine the
probability of the
offspring that is colorblind.
Express your answer in percentage. Solution Step
1 Identify the genotype both parents.
Heterozygous normal vision × Homozygous colorblind XC X ×
XCY
Step 2: Construct the Punnett square for the
cross.
X XC X XY
Step 3: Interpret the result.
1 XC XC = color blind daughter 1 XC X = carrier of
colorblindness trait daughter 1 XC Y= color blind
son 1 XY = son with normal vision
There is a 50% probability that the offspring will be
colorblind.
Let us Practice Both parents have normal color vision. They
had a daughter with normal vision
and a son
who is colorblind. What is the probability that the daughter is a
carrier
for the
color-blindness allele?
Example 3 Mr. Anderson has straight hair while Mrs.
Anderson has wavy hair. (The curly hair
gene shows incomplete dominance. There are two alleles,
curly- dominant and
straight- recessive. The heterozygote
has wavy hair.) The Andersons have a child
with
curly hair. Mr. Anderson accuses Mrs. Anderson of being unfaithful
to him. Is
he necessarily justified?
Why or why not? Show your Punnett square and the
corresponding solutions.
Solution Step 1 Identify the genotype of both parents.
Remember that Mr. Anderson has straight hair and Mrs
Anderson has wavy hair.
Step 3 Interpret the result.
Mr. Anderson’s justification could justified since
they have 0% chance of having a
child with
curly hair.
A non-Mendelian inheritance is a complex pattern of inheritance
that does
not follow the laws of heredity by Gregor
Mendel.
Incomplete dominance is a pattern of inheritance characterized by
the
formation of a trait that is in between the phenotypes of
the parents.
Codominance is a non-Mendelian type of dominance where the alleles
of a
gene pair in a heterozygote are fully
expressed.
Genes that go along with either sex chromosome is said to be
sex-linked.
For further information, you can check the following
links:
A. Identify the phenotypes of the given
genotypes.
10. XY
__________________________________________________
B. Compute for the possible blood type of child based from
the given data below.
Family name
Possible blood type of the child
Read the following questions carefully. Then, answer briefly.
1. How did the concept of non-Mendelian genetics come about?
2. What type of inheritance results in long radishes crossed with
round
radishes results in all oval radishes? Explain your answer.
3. Hemophilia is a recessive sex-linked trait associated with the
X
chromosomes in humans. If an unaffected male and carrier female
were
crossed, what is the probability of their children
inheriting the disease?
4. A woman has a daughter and she claims that one of the three men
is the
biological
father of her child. A paternity judge in the court requested
that
the woman, the daughter, and all three
men have their blood types
identified. The results
are mother, Heterozygous Type A; Daughter, Type O;
Man
#1, Type AB; Man #2, Homozygous Type B; Man #3, Type O based
on
the blood types. The
mother affirms that the results confirm that Man #3
is her daughter's father. Is she right? Why or why
not?
Not all traits are governed by a single gene. Most of
the time, the control in the
expression of a single trait is affected by
multiple genes. These genes may have a
single or multiple pairs of alleles responsible for
the high variation in the
phenotype. How
does multiple gene inheritance work?
Around and Around Materials:
color wheel Procedure:
1. Create a color wheel. Make a circle and
divide it into four parts. Use
the colors red,
blue, yellow and green for each part. Fasten
one arrow to a
metal brad and place at the
center of the
circle.
2. Record the color for each time the wheel
stopped.
1 2 3 4 5 6 7 8
9 10
Color
A monogenic inheritance involves only one gene and gives two
possible
Compare polygenic traits to other non-mendelian inheritance
traits by watching this
video.
User: Amoeba Sisters. 2015. ‘Incomplete dominance, codominance,
polygenic traits, and epistasis.’
https://www.youtube.com/watch?v=YJHGfbW55l0
Wondering how polygenic traits work? Click on this link.
User: Great Pacific Media. 2009. ‘Polygenic Inheritance.’
https://www.youtube.com/watch?v=gouqTq5p168
A. Put a check on the traits that are considered under polygenic
inheritance. 1. dimples 2. fur color 3. flower
color 4. seed shape 5. weight 6. height 7.
hemophilia 8. eye color 9. spots on animals
10. behavior B. Analyze the given statements below.
Write MGI for monogenic inheritance, PGI
8. Genes are inherited independently from each other. 9. The
inheritance that greatly contributes to very high variation
among
Read the following questions carefully. Then, answer
briefly.
1. Genes undergo a series of processes to be utilized in
controlling the
expression of traits among
individuals. Is it possible for living organisms to
have the same genes?
2. How do genes located on a single chromosome affect
heredity? 3. Is eye color controlled by a single gene?
Explain your answer. 4. Two different foster parents adopted
a monozygotic identical twins at birth.
One child raised by a wealthy family in Canada while a low-income
family
adopted the other child in the
Philippines. After 30 years, they met each
other and observed differences in their phenotypes. What are
the possible
factors that have caused these differences in
the identical twins?
Activity 2.1
Modelling Probability of Allele Inheritance
Objectives At the end of this laboratory activity, the
students should be able to:
determine how the parent’s alleles are segregated in the resulting
gametes
of the offsprings.
Materials and Equipment
2 small ziplock bags chocolate candies (2 red and 2
white)
Procedure
1. Put one red and one white chocolate candy on the first bag. The
red candy represents a dominant allele while the white
represents recessive allele. Label the bag as "mother's
allele".
Table 1. F1 Generation.
Draw Allele from Mom Allele from Dad F1
Genotype F1 Phenotype
1
2
Class Total
Guide Questions
1. What does each bean represent? 2. What trait is being
studied in this experiment? 3. Which genotype and phenotype
would most likely be expressed by the
offspring of F1 generation.
Tracing the Cause of Genetic Disorder Goal
You are tasked to do a case study for a family who would wish to
trace one
genetic disorder.
Role
You are a geneticist in a hospital who specializes with family
heredity. Audience
Your audience include the students and teachers from your
school. Situation
You were assigned to work on case study of a family who would wish
to
determine their family’s
genetic disorder. You are to assess the prevailing
problem of the disorder and find solution/s to the stated dilemma.
It will also
require a survey
questionnaire for the family’s interview. The case study
should consider one genetic disease. The proposed study
should be feasible
and supported by scientific research.
The final paper should be compiled in a
long
folder and should follow the guidelines for an academic
paper.
Product, Performance, and Purpose:
Standards and Criteria: Your performance will be
graded based on the rubric below.
Criteria Below
Exemplary 100%
Content Contents are related to the tasks
Less than 49% of the required components of
assigned contents were presented in the case
study.
50% - 70% of the the required components of
assigned contents were presented in the case
study.
75% - 90%of the required components of assigned
contents were presented in the case study.
100%.of the required components of assigned
contents were presented in the case study.
Organization Detailed facts are presented
completely and in a cohesive flow.
Details shown in the plan were few and not
cohesive throughout the submitted paper.
Details shown in the plan were few and began to
show cohesiveness throughout the submitted
paper.
Details shown in the plan were mostly complete
and showed cohesiveness throughout the submitted
paper.
Details shown in the plan were completed,
provided additional details, and shows
cohesiveness throughout the submitted
paper.
Quality The paper has complete components and
is neatly presented.
The product had incomplete components and
relationships are inaccurately
represented.
The product had components and relationships
represented.
The product was neat, components and
relationships are well represented.
The product was neat, components and
relationships are accurately detailed and
clearly represented.
Integrating concepts in Genetics Subject matter
is integrated and properly used in presenting
facts.
No concept of Genetics is not discussed in the
tasks.
Reflect on your understanding of the topic by
completing the sentences below.
Reflect
Chromatin This is a thread-like structure made up of
DNA.
Chromosome It is a condensed structure that came about due to
the
coiling of chromatin structures.
Codominance This is a form of dominance wherein the gene pair
is
expressed simultaneously in an
individual.
Deoxyribonucleic acid (DNA)
This is a long chain of nucleotide comprising of a
phosphate
group, a sugar group and nitrogenous bases
(adenine, thymine, guanine and
cytosine).
Dominant trait It is an allele that masks recessive traits.
This is
represented by a capital letter.
Enhancer region This is the one that interacts with the
transcription factor
to help the promoter region becomes
activated
Exons These are coding regions of a gene.
Gene This is a unit of heredity that contains DNA
segments.
Genotype These are set of genes that influences the
expression of
traits (phenotype)
Hemophilia It is a recessive genetic disorder that disables
blood clot
to occur.
Heterozygous It is also called as hybrids. This comprises of
one
dominant and one recessive allele.
Homozygous This set of allele is composed of both dominant or
both
recessive traits.
Incomplete dominance
It is a pattern of inheritance where the dominant alleles
are
not fully expressed and traits are blended.
Introns These are non-coding regions of a gene.
Law of dominance It is a mendelian principle that states that
dominant traits
will always masks the recessive
traits.
Law of independent assortment
This states that traits are independently inherited from
one
another.
Law of segregation It is a law that states that alleles are
segregated during
gamete formation and
fertilization.
Monogenic inheritance
It is a pattern of inheritance that involves only one gene.
Multiple gene inheritance
This is also called as polygenic inheritance. It is a trait
of
an individual controlled by more than one
gene.
Multiple allele These are genes that have more than a pair of
allele that
controls the expression of
traits.
Phenotype This is the observable traits which are controlled
by
genotype.
Promoter region It is a the regulatory sequences that
regulate the
activation of genes, which determine when and where
the
protein should be synthesized.
Punnett square This is a graphical representation used for
predicting
possible genotype and phenotypes.
Johnson, G.B., and Raven, P.H. 2001. Biology: Principles &
Explorations. Austin:
Holt, Rinehart and Winston. Klug, W.S., Spencer, C.A.,
and Cummings, M.R. 2016. Concepts of Genetics. Boston:
Pearson. Mader, S.S. 2014. Concepts of Biology. New
York: McGraw-Hill Education. Reece, J.B. and Campbell,
N.A. 2011. Campbell Biology. Boston: Benjamin
Cummings/Pearson.
Tamarin, R.H. 2004. Principles of Genetics. Boston:
McGraw-Hill. "Facts About Genetics: Chromosome18".
2018. Chromosome18.Org.
https://www.chromosome18.org/facts-about-genetics/.
Table of Contents
Objectives
Warm-Up