Albany College of Pharmacy Biology Lab Excises Table and Graph Report All the steps are attached. There are 3 thing that need to be done for this lab. First, Calculate p value with the method provided, Then Produce a graph using p values in excel. Least, answer the two analysis questions. There is one more picture will be added when this gets assign. This can be done in less than 2 hours, I guarantee. All the pictures are mostly steps on how to answer. MICROEVOLUTION AND HARDY-WEINBERG EQUILIBRIUM-EXERCISE 8 |
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4. No immigration or emigration – if there is migration of a large number of individuals into or out
of a population, then the frequency of particular alleles could shift.
5. No natural selection – when selective pressure, such as a change in environmental conditions
or the availability of food sources, acts on a population, individuals with traits adapted to surviv-
ing the selective pressure will be able to pass on their gene to their offspring at greater rates than
those who do not have the adaptive trait(s). When natural selection acts on a population, it can
result in an increase in some alleles and a decrease in others.
If one or more of these conditions are violated, then equilibrium would not occur. In nature it is uncom-
mon for populations of organisms to meet all five of these criteria. Thus, naturally occurring populations
rarely exhibit Hardy-Weinberg equilibrium. If conditions for Hardy-Weinberg equilibrium are violated, then
the population experiences changes allele frequencies over time. This is microevolution.
PART I. MICROEVOLUTION OF MULTIPLE ALLELE TRAIT: HUMAN ABO
BLOOD GROUP
You will model the inheritance of ABO blood types from parent to offspring using poker chips to rep-
resent alleles. There are three alleles, 14, 18, and i, which combine to produce six different genotypes. These
genotypes determine blood type (phenotype) in humans.
Genotype Phenotype
IA JA and lai
type A blood
B B and Bi
type B blood
TALB
type AB blood
ii
type O blood
Predict
What does the Castle-Hardy-Weinberg equilibrium predict for the classroom population?
.
PROCEDURE
1. Choose two poker chips from the gene pool jar – your parent genotype. In this exercise, red chips
= 14; blue chips = 1B; black chips = i. Record parent genotype in Table 1.
2. Randomly select a mate and create an offspring. Lay your two alleles on the table in front of you.
Your mate also will lay their two alleles on the table.
If your alleles are homozygous – do NOT roll the die, simply choose one allele from the
parent to contribute to the offspring
If your alleles are heterozygous – roll the die to determine the allele to contribute to your
offspring. Using dice models random mating – one of the requirements of C-H-W theory!
ODD numbers – donate the right allele to offspring genotype
EVEN numbers – donate the left allele to offspring genotype
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INVESTIGATING LIFE SCIENCE — Laboratory Manual
3. Combine the donated alleles from both you and your mate to generate the genotype of the first
generation. Record this genotype in the first generation in Table 1.
Example #1:
In step #1, you choose two red chips. This parent has a genotype IATA. You’ll write this down in Table
1. Then you choose a mate – 2 blue chips. This parent has the genotype IBIB. Because both parents are
homozygous, you do not need to roll the dice. Simply combine one allele from each parent to determine
the first generation genotype – IA from one parent and IB from the other. Record the offspring genotype
TAIB in Table 1.
–
–
Example #2
In step #1, you choose a red + a black chip. This parent has a genotype Mi. You’ll write this down in
Table 1. Then you choose a mate a blue + a black chip (Bi). Because both parents are heterozygous, you
must roll the dice two times one for each parent – to determine which allele is passed to the offspring.
On the first roll, you get a 6 (an even number), so the left allele in the first parent (IA) gets passed to the first
generation. On the second roll, you get a 3 (odd number), so the right allele in the second parent (i) gets
passed to the first generation. This results in an li genotype for the first generation. You’ll record this in
Table 1.
4. Repeat to produce one offspring for each parent. Each mating pair needs to produce two off-
spring. After the genotypes of both new offspring have been recorded, return the parent chips to
the gene pool jar and collect chips to represent the genotype of the offspring you just produced.
This offspring will now find a mate and reproduce.
5. Repeat steps #1-4 until you’ve completed ten generations. Do not mate with someone you have
already mated with.
6. Tally and record the number of individuals of each genotype in the class for each generation in
Table 2. Each row in this table should equal the number of individuals in the room who are partici-
pating in the game. This is a critical point and you must correct any errors before moving on to
data analysis.
Exercise 8
Microevolution and
Hardy-Weinberg Equilibrium
OBJECTIVES
You will:
model changes in allele frequencies in a population over
time
use Castle-Hardy-Weinberg theory to characterize the
genetic composition of a population
describe how natural selection drives changes in genetic
compositions of populations over time (microevolution)
SAFETY AND WASTE
MANAGEMENT
This lab does not use materials
that require special handling or
disposal.
Please organize lab materials and
clean up your lab table before
leaving.
BACKGROUND INFORMATION
Early in the twentieth century, W.E. Castle, G.H. Hardy and W. Weinberg separately devised a mathemati-
cal expression for predicting frequencies of genotypes in populations. They theorized that if one knows the
frequency of the alleles for a particular trait within a population, the frequencies of the genotypes and phe-
notypes could be predicted for the entire population and the frequencies of genotypes and alleles would
remain constant over time.
If a particular trait has two alleles, a dominant allele (A) and a recessive allele (a), then the frequencies
of all dominant alleles can be determined. The frequency of the dominant allele is assigned the value p.
The frequency of the recessive allele is assigned the value q. There are two expressions used to calculate
allele frequency:
Castle-Hardy-Weinberg Equation #1: P+= 1.0
This equation deals with the alleles in a population. It means that the total number of dominant alleles
(p) added to he total number of recessive alleles (q) equals the entire gene pool for that population (100%).
Castle-Hardy-Weinberg Equation #2:p2 + 2pq+q? = 1.0
This equation deals with the genotypes in a population. It means that the total number of homozygous
dominant individuals (p2) plus the total number of heterozygous individuals (2pq) plus the total number of
homozygous recessive individuals (q?) equals the entire population (100%).
Example: In a class of 24 students, four have curly hair, twelve have wavy hair and eight have straight
hair. In this example, A represents the curly hair allele and a represents the straight hair allele. Curly hair is
incompletely dominant over straight hair. This means the heterozygous genotype (Aa) will result in a phe-
notype that in intermediate between the dominant and recessive phenotype – in this case, wavy hair. Since
each student has two alleles for hair texture, there are 48 total alleles in the gene pool – 20 A alleles and 28
a alleles.
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INVESTIGATING LIFE SCIENCE – Laboratory Manual
Number of students
4
12
A alleles
8
Phenotype
curly hair
Genotype
AA
Аа
aa
Total alleles
Total alleles
8 A
12 A and 12 a
16 a
48
wavy hair
8
12
0
20
straight hair
Use Castle-Hardy-Weinberg Equation #1: p+q = 1.0 to determine the allele frequency in the student
population.
To determine the allele frequency (p) of the A allele:
p= number of A alleles present / total alleles in the gene pool
p = = 20/48 = 0.42 or 42% of the total alleles in the population are A alleles
To determine the frequency (q) of the a allele,
q=number of a alleles present/total alleles in the gene pool
q = 28/48 = 0.58 or 58% of the total alleles in the population are a alleles
Use Castle-Hardy-Weinberg Equation #2: p2 + 2pq+q? = 1.0 to determine the frequency of genotypes
in the population.
AA genotype: p? (0.42)2 = 0.18 (18%)
Aa genotype: 2pq = 2(0.42)(0.58) = 0.49 (49%)
aa genotype: q² = (0.58)2 = 0.34 (34%)
In other words, 18% of the population is homozygous dominant (AA), 49% of the population is hetero-
zygous (Aa) and 34% of the population is homozygous recessive (aa).
Castle, Hardy and Weinberg theorized that the frequencies of alleles in a population, and thus the
frequencies of the genotypes, will remain the same across generations of a population over time – what
is now called Castle-Hardy-Weinberg equilibrium. In order for a population to achieve Castle-Hardy-
Weinberg equilibrium, the following five conditions must be met.
1. Large population size – when there is a large number of individuals in a population, the loss of a
few does not significantly affect the proportion of alleles. If the population size is small, however,
then the loss of a few individuals can have a significant effect on allele frequency, and may lead to
genetic drift.
2. Totally random mating – in order for the proportion of alleles to remain constant over time, the
selection of mates must be random. When there is non-random mating, or sexual selection based
on some preferred characteristics of a mate, then the allele linked to that trait will be come more
common.
3. No mutations or mutation rates must be equal – in other words, the number of A → a mutations
must equal the number of a → A mutations
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INVESTIGATING LIFE SCIENCE — Laboratory Manual
Data Analysis
Calculate p value for 14 allele for each generation in class data. In Table 3, record the total number of IA
alleles for the class population and p value you calculate using the Castle-Hardy-Weinberg equation. Once
you have completed the table, use Excel to produce a graph using p values recorded in Table 3.
p value
Table 3: Calculation of p
Total 1A
Generation
in population
Parent
ou
First
13 tot 修域
Second
Third
(प
Fourth
18
Fifth
17
Sixth
(7 ㅋ
Seventh
(8
Eighth
15
Ninth
B 22
Tenth
21
ANALYSIS QUESTIONS
1. What does your graph mean in terms of the frequency of the l^ allele across generations?
2. Based on the trends in your graph, does our class population exhibit Hardy-Weinberg equilibrium?
Cite evidence from your graph and refer to at least 2 of the 5 conditions (listed in the background
section) required for equilibrium in your explanation.
WHAT YOU NEED TO TURN IN
For this lab, you need to turn in the data tables, your graph, and your responses to the analysis
questions. Be sure to write your name at the top of the page.
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