Unit 3 Flashcards
All mutations are harmful (T/F)
false. mutations can be good, bad, or neutral
What process is responsible for moving mutations around to different copies of a chromosome?
recombination
What process influences how the chromosomes after recombination are packed into gametes?
independent assortment
Most gametes have different genetic combinations (T/F)
True
Most people have never seen ___ % of the individuals of a species, including their own
99%
Variation can be easily categorized as good or bad (T/F)
false
Outliers and variations are a source of new combinations for nature to work with and therefore should not be considered problematic (T/F)
True
Types of sorting variation
stabilizing selection
directional selection
disruptive selection
Stabilizing selection (definition)
the process that explains the pattern of decreasing variance while the mean stays the same
Directional selection (definition)
the process that explains the pattern of the mean value of the characteristic changes
Disruptive selection (definition)
the process that explains the pattern of increasing variance and increasing extremes
Sexual dimorphism (definition)
distinct difference in phenotypes between the sexes of animals within the same species
What three processes make up the variation factory?
mutation
genetic recombination
independent assortment
Needs and environments can cause variation (T/F)
False. ONLY the variation factory is responsible for variation
Sexual selection (definition)
the process that explains differences in sexes within the same species
Sexual selection sorts heritable variation in non-random ways (T/F)
true
Sexual selection is a random process (T/F)
False
The production of variation is random but the sorting process is not (T/F)
True
Natural selection and sexual selection can only work independently of one another (T/F)
False. They can (and often do) work together
Random/Chance (definition)
lack of pattern or predictability
Non-random (definition)
presence of pattern or predictable event
How does chance relate to the sorting process? Could some biological patterns be due to chance?
Mutation occurs randomly by chance
Natural and sexual selection are non-random
Genetic drift occurs randomly by chance
Genetic drift (definition)
sorting of individuals/alleles due to chance
refers to random sorting NOT the event that is responsible for the sorting
In what cases is genetic drift more likely?
in small populations
for rare alleles
If males and females in a population are similar in their body form, size, and color, then this is evidence that sexual selection is not occurring in this population (T/F)
False
What process can explain bright coloration in male and female butterflies that helps to avoid predation?
sexual selection
Behaviors can be affected by differences in protein structure (T/F)
True
Behaviors can influence reproductive success (T/F)
True
Scientists have not directly observed the vast majority of variation that exists in living organisms (T/F)
true
What is something that you have in your body that is heritable?
Alleles
How can offspring inherit alleles that are not present in the body cells of their parents?
Mutations during DNA replication when gametes were made in their parents
There is selective pressure for organisms to have few or no new mutations in their genomes (T/F)
False
Which of the following is true about the “factory of variation production’?
- it is constantly occurring in all organisms undergoing cell division
- it is an unpreventable process
- it is originally responsible for the production of new alleles
all of the above are true
Genetic variants that are now common first originated as common variants in a large number of individuals (T/F)
false
Environmental conditions determine which mutations are most likely to occur (T/F)
false
In an evolutionary context, fitness refers to
the reproductive output of an individual
What is the random component of natural selection?
the occurrence and types of mutations
Which of the following is not necessary for natural selection?
- genetic variation
- environmental change
- differences among individuals in survival or reproduction
- transmission of alleles from parents to offspring
environmental change
Allele frequencies in a very large population of antelope changing by chance from one year to the next is due to genetic drift (T/F)
true
Can natural selection decrease the average fitness of individuals in the population?
No.
Can natural selection increase the degree to which a population’s average phenotype fits its environment?
Yes.
Genetic variation can be increased in a population by genetic drift (T/F)
false
The direction of an allele frequency change that occurs when a population is suddenly reduced to a very small size is not predictable (T/F)
true (it is not predictable)
