Download Biology 123 SI Chapter 22 and 23 What is a fossil? An imprint of a

Biology 123 SI Chapter 22 and 23
1.
What is a fossil? An imprint of a past organism left in rock
layers within the earth. The older ones are deeper.
2.
What is the meaning of descent with modification? It means
that natural selection functions through different generations
with gradual modifications overtime. This means that the animal
that is most fit for life in a specific environment will pass its
genes on more readily to future generations.
3.
What animal is Darwin famous for studying, and what did he
notice about them? Finches, and he noticed that they were all
similar, but adapted differently for life on the different islands
of the Galapagos.
4.
What are the three broad observations that Darwin studied?
The unity of life, the diversity of life, and the match between
animals and their environment.
5.
What is an evolutionary tree? It starts with a base organism
and continues to divide as new organisms adapt from it.
6.
What is artificial selection? When humans breed organisms to
have favorable characteristics that they might not normally
have in the wild. Ex. Small dogs and bigger produce.
7.
What are two observations that Darwin made that make
evolution possible? There is a wide variation even in a
particular inherited characteristic. And There are often more
offspring produced than can be supported by the environment.
This means that there is actually chance for bad traits to die off
and thus for good traits to accumulate in the environment.
8.
What is camouflage? When an organism blends into its
environment to fool predators or prey.
9.
What are homologous structures? They are similar
characteristic traits that were derived from common ancestry.
This is seen in the bones of the forelimbs of humans, wales, cats,
and bats. Also, the pharyngeal pouches and post-anal tail are
seen in both human and chick embryos.
10.
What are vestigial structures? Structures that are remnants of
features that had important functions in an organisms
ancestors.
11.
Describe the difference between convergent and analogous
evolution? Convergent evolution is the evolution of similar or
analogous features in distally related groups. Analogous
evolution is when traits arise when groups independently adapt
to similar environments. They are not distally related.
12.
What are the two hardy Weinberg equations and what do the
variables represent? P+q = 1 and p^2+q^2+2pq = 1. The p and
the q of the first equation represent the percentage of dominant
or recessive alleles. The p^2 and q^2 terms of the second
equation represent the percent frequency of the two
homozygous conditions and the 2pq term represents the
frequency of heterozygotes.
13.
What are the conditions required for a Hardy-Weinberg
population? No mutations, random mating, no natural
selection, extremely large population size, and no gene flow.
14.
A population has 2 alleles, A and a. The frequency of A is 30%.
What percentage of the population is heterozygous if the
population is in Hardy-Weinberg equilibrium.
42%
15.
What is microevolution? A change in allele frequencies in a
population over generations due to natural selection, genetic
drift (chance events that alter allelic frequencies), or gene flow
(moving alleles into or out of populations). This is all possible
because of genetic variation.
16.
What must be mutated in order for a mutation to be passed on
to an offspring? The DNA of gametes must be changed.
17.
What are two main things that help increase genetic variability?
Formation of new alleles, alternation of gene number or
position, Rapid reproduction because it makes populations
change faster because of evolution and it increases the chance
of mutations. Sexual reproduction because crossing over,
independent assortment, and fertilization.
18.
How can Hardy-Weinberg be used to tell if a population is
evolving? If allele and genotype frequencies hold constant for a
long time, the population is not evolving.
19. What are the founder and bottleneck effects?
Founder effect occurs when a few individuals become isolated in a
population
Bottleneck effect is a sudden drastic reduction in population usually
due to climate changes.
20. What is genetic drift?
Genetic drift is more significant in small populations, and it can cause
to a loss in genetic variation, and it can also cause bad alleles to
become fixed. (chance events that alter allelic frequencies)
21. What is gene flow?
Movements of alleles through different populations. (like pollen
traveling) This reduces genetic variablilty overall.
22. What are three types of selection and how are they different?
directional favors individuals on one end of the spectrum,
disruptive favors individuals at the two opposite ends of the
spectrum of phenotype, and stabilizing favors individuals of
intermediate phenotype.
23. What is phylogeny? The evolutionary history of a species.
24.
What is Systematics? It is a discipline that classifies organisms
and determines evolutionary relationships
25.
What is taxonomy? An ordered naming scheme
26.
What are the different naming classifications of organisms?
Domain kingdom phylum class order family genus species