Bio 112 Lab Exam 1 TAMU Questions
with Complete Solutions.
population - Answer All organisms of the same group or species that inhabit the same area
and can interbreed
genetics - Answer The study of how the characteristics of one generation are passed on to the
next
genetic structure - Answer Distribution of genotype frequencies within a population
evolution - Answer The change in heritable characteristics of a population over generations
selection - Answer The process whereby a genotype increases or decreases in frequency
because it confers a benefit or a detriment to the organism, which results in differential survival.
genes - Answer Consist of a specific DNA sequence the encodes the synthesis of a product
(usually a protein)
allele - Answer Different forms of a gene
genotype - Answer The genetic make-up of an organism (i.e., AA or aa)
phenotype - Answer The physical trait, appearance, or other characteristic of an organism as a
result of genotype and the environment (i.e. black or red)
What is Hardy-Weinberg equilibrium? - Answer HWE is observed when a population's allelic
and genotypic frequencies do NOT change. In other words, there is no evolutionary force acting
on the population
What are the assumption of HWE? - Answer No Selection, No Gene flow, Random mating,
Infinite population size, No mutation
Is it really possible for a population to be in HWE? - Answer no
Why is Hardy-Weinberg used in population genetics? - Answer It is used as a null model, or, in
other words, as a point of comparison. By comparing real populations to HW, we can determine
if they are evolving (and generally, at what rate)
, What are the five evolutionary processes? - Answer mutation, gene flow, genetic drift, natural
selection, and sexual selection
Classify each of the five evolutionary processes as random or non-random. - Answer Random:
Mutation, Genetic Drift, (Gene Flow)
Non-Random: Natural and Sexual Selection, (Gene Flow)
Individuals that reproduce poorly in a population tend to emigrate the next year. In this
scenario, is gene flow random or non-random? - Answer This would imply that individuals
with specific genotypes are emigrating. Thus, this is a NON RANDOM example of Gene Flow,
which can be random or nonrandom.
Which of the evolutionary processes require genetic variation within a population in order to
work? - Answer Natural and Sexual Selection
The Founder's effect is an extreme type of which evolutionary process? - Answer Genetic drift
Describe how you would expect the allelic and genotypic frequencies of a population to change
when subjected to each of the five evolutionary processes (Genetic drift) - Answer frequencies
will change randomly - if the population is small enough, it may lead to the fixation of one of the
alleles.
Describe how you would expect the allelic and genotypic frequencies of a population to change
when subjected to each of the five evolutionary processes (Natural selection) - Answer
frequencies will change specifically to favour the "most fit" genotype, increasing the allele
frequencies associated with that genotype. If homozygous recessive individuals have better
camouflage, then the aa genotype will increase and the a frequency will increase.
Describe how you would expect the allelic and genotypic frequencies of a population to change
when subjected to each of the five evolutionary processes( sexual selection) - Answer like
natural selection, but instead, imagine that the homozygous recessive has more colorful
plumage.
Describe how you would expect the allelic and genotypic frequencies of a population to change
when subjected to each of the five evolutionary processes (gene flow) - Answer If gene flow is
random, population frequencies will shift randomly after the loss/intake of individuals. Consider
a population where AA reproduce poorly and emigrate. Over time, even if some AA individuals
are produced, they will leave the population, causing allelic frequencies for AA in the "source"
population to drop. However, AA will increase in the destination population (as well as A
frequency).
with Complete Solutions.
population - Answer All organisms of the same group or species that inhabit the same area
and can interbreed
genetics - Answer The study of how the characteristics of one generation are passed on to the
next
genetic structure - Answer Distribution of genotype frequencies within a population
evolution - Answer The change in heritable characteristics of a population over generations
selection - Answer The process whereby a genotype increases or decreases in frequency
because it confers a benefit or a detriment to the organism, which results in differential survival.
genes - Answer Consist of a specific DNA sequence the encodes the synthesis of a product
(usually a protein)
allele - Answer Different forms of a gene
genotype - Answer The genetic make-up of an organism (i.e., AA or aa)
phenotype - Answer The physical trait, appearance, or other characteristic of an organism as a
result of genotype and the environment (i.e. black or red)
What is Hardy-Weinberg equilibrium? - Answer HWE is observed when a population's allelic
and genotypic frequencies do NOT change. In other words, there is no evolutionary force acting
on the population
What are the assumption of HWE? - Answer No Selection, No Gene flow, Random mating,
Infinite population size, No mutation
Is it really possible for a population to be in HWE? - Answer no
Why is Hardy-Weinberg used in population genetics? - Answer It is used as a null model, or, in
other words, as a point of comparison. By comparing real populations to HW, we can determine
if they are evolving (and generally, at what rate)
, What are the five evolutionary processes? - Answer mutation, gene flow, genetic drift, natural
selection, and sexual selection
Classify each of the five evolutionary processes as random or non-random. - Answer Random:
Mutation, Genetic Drift, (Gene Flow)
Non-Random: Natural and Sexual Selection, (Gene Flow)
Individuals that reproduce poorly in a population tend to emigrate the next year. In this
scenario, is gene flow random or non-random? - Answer This would imply that individuals
with specific genotypes are emigrating. Thus, this is a NON RANDOM example of Gene Flow,
which can be random or nonrandom.
Which of the evolutionary processes require genetic variation within a population in order to
work? - Answer Natural and Sexual Selection
The Founder's effect is an extreme type of which evolutionary process? - Answer Genetic drift
Describe how you would expect the allelic and genotypic frequencies of a population to change
when subjected to each of the five evolutionary processes (Genetic drift) - Answer frequencies
will change randomly - if the population is small enough, it may lead to the fixation of one of the
alleles.
Describe how you would expect the allelic and genotypic frequencies of a population to change
when subjected to each of the five evolutionary processes (Natural selection) - Answer
frequencies will change specifically to favour the "most fit" genotype, increasing the allele
frequencies associated with that genotype. If homozygous recessive individuals have better
camouflage, then the aa genotype will increase and the a frequency will increase.
Describe how you would expect the allelic and genotypic frequencies of a population to change
when subjected to each of the five evolutionary processes( sexual selection) - Answer like
natural selection, but instead, imagine that the homozygous recessive has more colorful
plumage.
Describe how you would expect the allelic and genotypic frequencies of a population to change
when subjected to each of the five evolutionary processes (gene flow) - Answer If gene flow is
random, population frequencies will shift randomly after the loss/intake of individuals. Consider
a population where AA reproduce poorly and emigrate. Over time, even if some AA individuals
are produced, they will leave the population, causing allelic frequencies for AA in the "source"
population to drop. However, AA will increase in the destination population (as well as A
frequency).
