Question 1

Which of the following best describes the main purpose of mitosis in multicellular organisms?

Accepted Answer

To generate new diploid cells that are genetically identical to the parent cell

Question 2

During which phase of the cell cycle does DNA replication occur?

Accepted Answer

S phase

Question 3

A mutation occurs in a gene coding for a DNA repair enzyme. What is the most likely consequence?

Accepted Answer

Increased risk of cancer due to accumulation of DNA errors

Question 4

Which of the following statements about meiosis is correct?

Accepted Answer

It results in four non-identical haploid gametes

Question 5

What is the role of tRNA during translation?

Accepted Answer

To escort specific amino acids to the ribosome and match them to the mRNA codon

Question 6

Which of the following codons serves as the universal start codon for translation?

Accepted Answer

$$\mathrm{AUG}$$

Question 7

A cell is observed to have 23 pairs of chromosomes, with one pair being XY. Which statement is true about this cell?

Accepted Answer

It is a diploid somatic cell from a male

Question 8

Which process is responsible for the genetic variation observed in offspring produced by sexual reproduction?

Accepted Answer

Crossing over during prophase I of meiosis

Question 9

If a mutation occurs in a somatic cell, what is the most likely outcome?

Accepted Answer

The mutation may affect tissue function or cause cancer, but will not be inherited by offspring

Question 10

Which of the following best explains why all cells in the human body (except gametes) have the same DNA but different functions?

Accepted Answer

Different genes are expressed in different cell types due to environmental and developmental factors

Question 11

A researcher is attempting to clone a sheep using somatic cell nuclear transfer. Which of the following steps is essential for this process?

Accepted Answer

Inserting a somatic cell nucleus into an enucleated egg

Question 12

Which checkpoint in the cell cycle ensures that DNA has been accurately replicated before mitosis begins?

Accepted Answer

G2 checkpoint

Question 13

A patient is exposed to a chemical that inhibits the activity of DNA polymerase. What is the most immediate effect on the cell cycle?

Accepted Answer

DNA replication will not occur, preventing the cell from entering mitosis

Question 14

Which of the following is a direct result of unequal cytokinesis during female meiosis?

Accepted Answer

One viable egg and three polar bodies are produced

Question 15

A zygote divides several times without growing, forming a ball of 16 cells. What is the significance of this stage in development?

Accepted Answer

Cells are not yet differentiated and can be used for embryo splitting to produce clones

Question 16

Which of the following environmental factors is most likely to cause physical deformities if exposure occurs during late fetal development?

Accepted Answer

Prescription medications that cross the placenta

Question 17

Which of the following best describes the process of transcription?

Accepted Answer

Copying DNA of a gene into mRNA within the nucleus

Question 18

A cell is observed in metaphase during mitosis. Which of the following best describes what is occurring?

Accepted Answer

Duplicated chromosomes are aligned in a single line at the cell's equator

Question 19

Which of the following is a key ethical concern associated with therapeutic cloning?

Accepted Answer

The creation and destruction of human embryos

Question 20

A mutation in a gamete is most likely to result in which of the following?

Accepted Answer

Transmission of the mutation to future generations

Cell Reproduction and Differentiation: Study Notes for Human Biology

Study Guide - Practice Questions