Question 1

Which of the following best describes the relationship between a signaling molecule (ligand) and its receptor in cellular communication?

Accepted Answer

The ligand and receptor interact through a lock-and-key mechanism, where the ligand's shape is complementary to the receptor's binding site.

Question 2

During a signal transduction cascade, phosphorylation is a key event. What is the primary role of phosphorylation in this process?

Accepted Answer

It activates or deactivates proteins by adding a phosphate group, thereby propagating the signal.

Question 3

Which of the following is an example of long-distance signaling in animals?

Accepted Answer

Hormones released into the bloodstream affecting distant organs

Question 4

A mutation causes a cell to skip the G1 checkpoint in the cell cycle. Which of the following is a likely consequence?

Accepted Answer

The cell may divide uncontrollably, potentially leading to cancer.

Question 5

During which phase of meiosis does crossing over occur, and what is its significance?

Accepted Answer

Prophase I; it increases genetic variation by exchanging genetic material between homologous chromosomes.

Question 6

A woman with genotype $$X^N X^n ($$where $$N is $$normal vision and $$n is $$colorblindness) and a man with genotype $$X^n Y$$ have a child. What is the probability that their son will be colorblind?

Accepted Answer

$$0.50$$

Question 7

Which of the following best explains Mendel’s law of independent assortment?

Accepted Answer

Alleles for different genes segregate independently of one another during gamete formation.

Question 8

A plant with genotype $$RrYy ($$where $$R = $$round, $$r = $$wrinkled, $$Y = $$yellow, $$y = $$green) is self-crossed. What is the expected phenotypic ratio among the offspring?

Accepted Answer

$$9$$ round yellow : $$3$$ round green : $$3$$ wrinkled yellow : $$1$$ wrinkled green

Question 9

Which of the following is an example of incomplete dominance?

Accepted Answer

A red-flowered plant crossed with a white-flowered plant produces pink-flowered offspring.

Question 10

A geneticist is studying a trait controlled by two genes that interact so that one gene masks the expression of the other. This is an example of:

Accepted Answer

Epistasis

Question 11

Which of the following best describes the difference between chromatin and chromosomes?

Accepted Answer

Chromatin is DNA wrapped around proteins during interphase, while chromosomes are the highly condensed form of DNA visible during mitosis.

Question 12

A couple has a child with Down syndrome (trisomy 21). Which of the following best explains how this condition arises?

Accepted Answer

Non-disjunction during meiosis leads to an extra copy of chromosome 21 in the gamete.

Question 13

Which of the following statements about sex determination in humans is correct?

Accepted Answer

The presence of a Y chromosome, specifically the SRY gene, determines maleness.

Question 14

A testcross is performed between a plant with an unknown genotype and a homozygous recessive plant. If all offspring display the dominant phenotype, what is the genotype of the unknown parent?

Accepted Answer

Homozygous dominant

Question 15

Which of the following best describes the product rule in genetics?

Accepted Answer

The probability of two independent events both occurring is the product of their individual probabilities.

Question 16

Which of the following is a real-world example of pleiotropy?

Accepted Answer

A single gene mutation causing both sickle-shaped red blood cells and increased resistance to malaria.

Question 17

Which of the following best explains how we know that genes are located on chromosomes?

Accepted Answer

Experiments showing that traits are inherited together with specific chromosomes during meiosis.

Question 18

A woman who is heterozygous for a mitochondrial disorder marries a man who is unaffected. What is the probability that their children will inherit the disorder?

Accepted Answer

All children will inherit the disorder.

Question 19

Which of the following scenarios best illustrates polygenic inheritance?

Accepted Answer

Human skin color is determined by the additive effects of several genes.

Question 20

A cell in metaphase of mitosis has 8 chromosomes. How many chromosomes will each daughter cell have after cytokinesis?

Accepted Answer

8

General Biology Study Guide: Cell Communication, Cell Cycle, Meiosis, and Mendelian Genetics (Ch. 11-15)

스터디 가이드 - 연습 문제

학습 가이드 - 플래시카드