Chapter 23 Flashcards
What is polygenetic inheritance?
A characteristic that is controlled by more than one gene.
What is a genotype?
Is defined as the composition of genes which also includes both expressed and unexpressed
What is a phenotype?
It is the physical outcome of genes, the expressed allele.
how does natural selection work on a population?
A population can have natural selection work on their GENOTYPES. As individuals they only work on phenotypes.
Can natural selection work on individual genotypes?
Only on the alleles that are expressed and only on a population.
What is an example of a polygenic inheritance?
The two caterpillars that look very different but turn into the same type of moth. They are different in appearances to chemicals in their diets, not differences in their genotypes.
How is microevolutionary change measure?
It can be measured in the difference of allele frequencies over time. (Rabbit diagram with white and brown bunnies)
What is the Hardy-Weinberg equilibrium equation? what does each part represent?
P^2 + 2pq + q^2 = 1;
P^2 = the frequency of the dominant allele in a population. (Homozygous Dominant)
q^2 = the frequency of the recessive allele in a population. (Homozygous Recessive)
2pq = Heterozygous
Does the Hardy-Weinberg equation have to equal 1?
Yes the frequencies of the three genotypes must equal 1 (100%) in any population.
What are the conditions or assumptions of Hardy-Weinberg Equilibrium?
- No mutations
- Random mating
- No natural selection
- Extremely large population size
- No gene flow
What was talked about about the Underwing Moths?
They camouflage in with the tree but if they are ever scared they will open up their wings where bright colors will show. It will scare predators away.
Why are peppered moths so famous?
Their experiments were said to “prove” evolution wrong because they saw that one moth lands on the tops of trees, while the black moths would land on the trunks of tree that turned black from soot.
What are the two types of genetic drift?
Founder effect and the bottle neck
What is the founder effect?
The founder effect is when a few individuals from a population start a new population with a different allele frequency than the original population. (When a storm blows some bugs from one island to another and they start to breed.)
What is the bottle neck effect?
It could happen because of diseases and disasters etc. A bottle can be full of diverse alleles but through bottle necking only a few survive. (examples of bottle neck is the cheetah and the prairie chicken) Bottle Neck causes allele pools to become a lot smaller and most wont be able to survive.
