Chapter 23 AP biology – Flashcards

Natural selection changes allele frequencies because some _______ survive and reproduce more successfully than others.

No two people are genetically identical, except for identical twins. The main source of genetic variation among human individuals is

Sparrows with average-sized wings survive severe storms better than those with longer or shorter wings, illustrating

If the nucleotide variability of a locus equals 0%, what is the gene variability and number of alleles at that locus?

There are 40 individuals in population 1, all with genotype A1A1, and there are 25 individuals in population 2, all with genotype A2A2. Assume that these populations are located far from each other and that their environmental conditions are very similar. Based on the information given here, the observed genetic variation is most likely an example of

In the context of populations, how do we define evolution?

The mechanisms that can alter allele frequencies

Which example below correctly describes average heterozygosity?

Which example below would most likely exhibit a cline?

Which of the following can form entirely new alleles?

Sexual recombination includes the shuffling of chromosomes in _____ and fertilization.

Which type of mutation plays the most important role in increasing the number of genes in the gene pool?

In the Hardy-Weinberg equation, p2 represents _____.

In the equation for Hardy-Weinberg equilibrium, 1 represents _____.

conditions required for Hardy-Weinberg equilibrium?

_____ and _____ generate variation, whereas _____ results in an adaptation to the environment.

A population of 15 birds inhabits a fairly new island. Ten of the birds are dark brown and five of them are light brown. By chance, two of the dark brown birds and three of the light brown birds die before producing any offspring. All of the birds in the next generation are dark brown. This change in phenotypic frequency can be attributed to _____.

An earthquake hits a small island. All but a small group of closely related lizards are eliminated, and the survivors spread out over the island. This is an instance of _____.

Which of the following scenarios would most likely result in the microevolution of a population of humans?

Which of the following is the best example of gene flow?

Which of the following most accurately measures an organism's fitness?

Antibiotic resistance in bacteria is an example of which of the following?

For several years, scientists have warned doctors of the danger of overprescribing antibiotics such as penicillin. Scientists are concerned because _____.

A population of squirrels is preyed on by small hawks. The smaller squirrels can escape into burrows. The larger squirrels can fight off the hawks. After several generations, the squirrels in the area tend to be very small or very large. What process is responsible for this outcome?

Stabilizing selection _____.

Birds with average-size wings survived a severe storm more successfully than other birds in the same population with longer or shorter wings. If severe storms occur regularly, then over time, one should expect these storms to bring about _____. (

Which type of selection maintains stable frequencies of two or more phenotypic forms in a population?

neutral variation

What is the importance of neutral variation in evolution?

Selection that acts over evolutionary time to preserve traits that increase an individual's ability to mate is known as _____.

Which statement below is true about sexual selection?

How does natural selection fashion organisms?