Biology 1013 Launchpad 13.3-13.5, 13.6, & 13.7

Why is gene transfer among bacteria significant to human health?

A gene carrying antibiotic resistance can be transferred among bacteria, decreasing the likelihood that the antibiotic is effective in treating certain diseases.

Select the statement that describes how fitness and natural selection interact to lead to adaptation.

Alleles well-suited to the environment increase the fitness of organisms, allowing for higher survival and reproduction so that the beneficial alleles are passed on to future generations and increase in incidence in the population over time.

What happens to the parent cell during binary fission?

It elongates, replicates its DNA, and divides in two.

Select the statement that describes how an organism's fitness level and environment relate to one another.

The more suitable an environment is for an organism's phenotype, the higher the organism's fitness level.

Select the explanation for why a phenotype is selected for in the first environment but selected against in the second environment.

The phenotype leads to higher rates of survival and reproduction in the first environment but lower rates of both in the second environment.

What is the result of binary fission?

two daughter cells with genetic material identical to that of the parent cell

Select the scenarios that show how an organism's fitness is dependent on the environment. Select the TWO answers that are correct.

~A population of field mice in the forest has lower survival rates than the population in the state park. ~A butterfly living in a wildflower field has higher reproduction rates than the same butterfly living in a wooded area.

Select the scenarios that describe stabilizing selection. Select the TWO answers that are correct.

~Cats with short tails do not balance well, and cats with long tails are clumsy. ~In chickens, eggs of intermediate weight show the highest rate of hatching.

Select the scenarios that describe diversifying selection. Select the TWO answers that are correct.

~In a patchy underwater habitat, light-colored oysters blend into the rocks and dark-colored oysters blend into the shadows. ~In a species of butterfly, both the white- and black-winged adults are toxic to predators, but the gray-winged butterflies are not.

If bacteria reproduce through asexual reproduction, how does genetic variation occur?

~mutations ~gene transfer