Download Unit 1 Rev 4 - Mr. Lesiuk

Name : ________________
Date: _______
Biology 11 Unit 1 - : Review #4
UNIT # 1 ADAPTATION AND EVOLUTION – Read pp.299-302
(Learning Outcome : Allelic Frequencies of a Population Can Change/Disrupting
Genetic Equilibrium.
____1. The following data was collected from a representative sample of a larger
population: In this population of wild hamsters there is a gene for tail length. For
this gene there are two alleles "L" is dominant for "long tailed"; while "l" is
recessive for "short tailed". 25 Hamsters are trapped and their DNA is taken back
to the lab, after running DNA fingerprinting (Gel Electrophoresis) each hamsters
genotype was determined. Use the data below to answer the rest of question #1.
Ll
ll
Ll
Ll
ll
ll
ll
Ll
Ll
ll
ll
ll
Ll
ll
ll
Ll
Ll
Ll
ll
LL
Ll
Ll
ll
Ll
Ll
A) What are the allelic frequencies
B) What is the Genotypic Ratio for this population
C) What is the Phenotypic Ration for this population
_____2. Use a punnett square to run a test cross between a heterozygous long tailed
hamster and a short-tailed hamster. Give the F1 Genotypic Ratio.
___ 3. What state (condition) has been established when the proportion of an allele
(allelic frequencies) in a gene pool for a population remains the same from
one generation to another for a long period of time.
____4. List 5 key conditions that must be maintained in order for this gene pool to
remain in this condition of no change? (see the bulleted points in the
population equilibrium handout)
___ 5. List six different types of pressures or forces that can be put on a population
leading to a disturbance to its gene pool allowing evolution to take place. (see
notes "Factors Affecting Gene Frequency" handout)
___ 6. State the "Hardy Weinberg Principle"
___ 7. What is the process called in which mates are chosen by a particular
phenotype?
___ 8. Regardless of genetic equilibrium; in reality the conditions to maintain
genetic equilibrium are rarely maintained for very long, so what will usually
happen to the frequency of an allele which codes for a “desired/favored”
phenotype?
OVER 
___ 9. Give an example of how differential migration in the hamster population
that was used in question #1 could alter the allelic frequencies in the gene
pool, use the words immigrate and
emigrate..
____10. What is the process called in which a small group of individuals is
separated from the main population?
____11. What affect does natural selection have on two different competing alleles?
___12. Why is it that most mutations that arise are usually not as successful as the
existing genes in the gene pool.
___13. Describe Random Genetic Drift? (Think back to flipping pennies)
___14. What happened in class to the allelic frequencies for the “Penny” gene,
which originally started with a 0.5 (heads) : 0.5 (tails) allelic frequencies.
____15. Of the six main forces/factors that work to disrupt Genetic Equilibrium,
name the THREE that are considered the biggest drivers of evolution. (think
back to the DVD we watched "Mechanisms of Evolution"
____16. Write out the definition for “GENE POOL”
For ENTERTAINMENT purposes only:
DARWIN AWARDS – Cleaning up the Human Gene Pool