biology chapter 16

Question 1

evolution

Answer 1

the change in the genetic makeup of a population with time

Question 2

fossils

Answer 2

are the most direct evidence of evolutionary change

Question 3

actual remains

Answer 3

including teeth, bones, etc,. Found in rock, tar pits, ice and amber (the fossil resin of trees)

Question 4

petrification

Answer 4

is the process in which minerals replace the cells of an organism

Question 5

imprints

Answer 5

are impressions left by an organism, i.e. footprints

Question 6

molds

Answer 6

form in hollow spaces of rocks, as the organisms within decays

Question 7

casts

Answer 7

are formed by minerals deposited in molds

Question 8

homologous structures

Answer 8

have the same basic anatomical features and evolutionary origins. They demonstrate similar evolutionary patters with late divergence of form due to differences in exposure to evolutionary forces

Question 9

analogous structure

Answer 9

have similar functions but may have different evolutionary origins and entirely different patterns of development. Analogous organs demonstrate superficial resemblance which cannot be used as a basis for classification

Question 10

vestigial structures

Answer 10

are structures that appear to be useless but apparently had some ancestral function

Question 11

Darwin’s theory of Natural Selection

Answer 11

1. overpopulation 2. variations 3. competition (struggle for survival) 4. natural selection 5. inheritence of the variations 6. evolution of new species

Question 12

population

Answer 12

includes all members of a particular species inhabiting a given location

Question 13

gene pool

Answer 13

of a population is the sum total of all the alleles for any given trait in the population

Question 14

gene frequency

Answer 14

is the decimal fraction representing the presnece of an allele for all memebers of a population that have this particular gene locus.

Question 15

p

Answer 15

is used for the frequency of the dominant allele of a particular gene locus

Question 16

q

Answer 16

represents the frequency of the recessive allele

Question 17

Hardy-Weinberg Principles

Answer 17

1. the population is very large 2. there are no mutations that affect the gene pool 3. mating between individuals in the population is random 4. there is no net migration of individuals into or out of the population 5. the genes in the population are all equally successful at reproducing

Question 18

Hardy-Weinberg equation

Answer 18

p2 + 2pq + q2 = 1

Question 19

agents of microevolutionary change

Answer 19

natural selection, mutation, assortive mating, genetic drift, and gene flow

Question 20

natural selection

Answer 20

genotypes with favorable variations are selected through natural selection, and the frequency of favorable genes increases within the gene pool. Genotypes with low adaptive values tend to disappear

Question 21

mutations

Answer 21

gene mutations change allele frequencies in a population, shifting gene equilibria

Question 22

assortive mating

Answer 22

if mates are not randomly chosen, but rather selected according to criteria such as phenotype and proximity, the relative genotype ratios will be affected, and will depart from the predictions of the Hardy-Weinberg equilibrium. On the average, the allele frequencies in the gene pool remain unchanged

Question 23

genetic drift

Answer 23

refers to changes in the composition of the gene pool due to chance. Genetic drift tends to be more pronounced in small populations, where it is sometimes called the founder effect

Question 24

gene flow

Answer 24

migration of individuals between populations will result in a loss or gain of genes, and thus change the composition of a population’s gene pool

Question 25

speciation

Answer 25

is the evolution of new species, which are groups of individuals who can interbreed freely with each other, but not with members of other species.

Question 26

deme

Answer 26

is a small local population

Question 27

adaptive radiation

Answer 27

is the emergence of a number of lineages from a single ancestral species

Question 28

heterotrophs

Answer 28

depend upon outside sources for food