Biology Semester 2 Review

Which statement BEST describes the role of gene expression in cells?

• Cells destroy the DNA of genes that they do not use.

• To become specialized, cells need to control the production of proteins coded for in their DNA.

• When cells divide in mitosis, they pass on the genes that are required.

• All genetic information in a cell's DNA is fully expressed all the time.

Scientists have developed methods that allow the insertion of a gene into a bacterium. How might this biotechnology be helpful to someone who has diabetes?

• A person with diabetes can regulate insulin production by eating products the contain the special bacterium and the new gene.

• When the bacterium reproduces, it passes the gene for human insulin to its offspring. The offspring form a colony of bacteria that contain the gene for human insulin, which can then be used to produce insulin for a person with diabetes.

• The bacterium itself can be used as a treatment for a person with diabetes because it can deliver the genes for human insulin to that person's cells.

Cells in your hair follicles produce the protein keratin. Cells in your liver do not produce keratin. Which statement explains these differences?

• Hair follicles contain recombinant DNA, which creates the protein keratin.

• Hair follicle cells contain different genes from liver cells.

• Hair follicle cells do not produce DNA, but liver cells do.

• Genes are expressed differently in liver cells and hair follicles.

Which statement BEST explains how an embryo can produce a different type of hemoglobin from that of an infant, child, or adult?

• Human genes change slowly as a person ages.

• As the embryo develops and cells differentiate, certain genes are lost.

• An embryo and an adult have different genes for hemoglobin.

• Humans have genes for different types of hemoglobin, and they are expressed at different times.

Cells control gene expression at which steps?

• mitosis, meiosis, and the formation of the final protein

• transcription, translation, and the formation of the final protein

• interphase, prophase, and metaphase

• transcription, mitosis, and DNA replication

After which event could you say that evolution has occurred?

• An allele frequency in a population changes over time.

• A new predator comes into an environment.

• An animal's white winter coat is replaced by a darker coat in the spring.

• An individual is born with six fingers on one hand instead of five.

Which situation would MOST LIKELY result in evolution?

• A single individual dies in a large population.

• A butterfly predator sees yellow more easily than it does green, and a population of butterflies includes both phenotypes.

• A green parrot has an allele for green feathers and an allele for blue feathers.

• A large population continues to grow.

A population of snails is experiencing disruptive selection in terms of their shell patterns. Which graph represents the population?

• Graph A

• Graph B

• Graph C

• Graph D

A bat wing, an alligator leg, and a human arm are homologous structures. Which fact about those structures BEST supports one aspect of the theory of evolution?

• The fact that the bone structures are completely different supports the concept that those organisms shared a common ancestor.

• The fact that the bone structures are similar supports the concept that birds evolved from mammals.

• The fact that the bone structures are similar supports the concept that the animals shared a common ancestor.

Which outcome can occur when two segments of a population become geographically isolated?

• Both group most likely become extinct.

• They eventually become separate species.

• The two segments continue to freely exchange genetic material.

• They can only share some types of genes.