Question 1

A couple is concerned about the risk of genetic disorders in their unborn child. Which prenatal test involves sampling placental tissue to analyze the fetus's chromosomes?

Accepted Answer

Chorionic villus sampling

Question 2

A woman is diagnosed with Turner syndrome. Which of the following best describes her chromosomal composition?

Accepted Answer

45, X

Question 3

Which of the following genetic disorders is caused by a dominant allele and leads to progressive nervous system degeneration?

Accepted Answer

Huntington's disease

Question 4

A scientist is studying a gene that affects both skin color and vision in mice. This is an example of which genetic phenomenon?

Accepted Answer

Pleiotropy

Question 5

In a dihybrid cross between two heterozygous pea plants ($$RrYy 	imes RrYy$$), what is the expected phenotypic ratio of the offspring if the genes assort independently?

Accepted Answer

$$9:3:3:1$$

Question 6

Which process during meiosis increases genetic variation by exchanging genetic material between homologous chromosomes?

Accepted Answer

Crossing over

Question 7

A mutation changes a codon from $$UAC ($$tyrosine) to $$UAA ($$stop codon). What type of mutation is this?

Accepted Answer

Nonsense mutation

Question 8

Which enzyme is responsible for synthesizing new DNA strands during DNA replication?

Accepted Answer

DNA polymerase

Question 9

A researcher uses PCR (Polymerase Chain Reaction) in a forensic investigation. What is the main purpose of PCR in this context?

Accepted Answer

To amplify specific DNA sequences

Question 10

Which of the following best explains why males are more likely to express X-linked recessive disorders than females?

Accepted Answer

Males inherit only one X chromosome, so a single recessive allele will be expressed

Question 11

A cell is observed to have DNA wrapped around histone proteins. What is the resulting structure called?

Accepted Answer

Nucleosome

Question 12

Which of the following best describes the function of a repressor protein in gene regulation?

Accepted Answer

It blocks gene expression by binding to the operator

Question 13

A patient is diagnosed with a malignant tumor that has spread to other organs. What is the term for this process?

Accepted Answer

Metastasis

Question 14

During protein synthesis, which type of RNA brings amino acids to the ribosome?

Accepted Answer

tRNA

Question 15

A DNA sequence is changed from $$5'-ATG CCG TAA-3' to$$ $$5'-ATC CGT AA-3'. $$What type of mutation has occurred?

Accepted Answer

Frameshift mutation

Question 16

Which of the following best describes the role of the promoter region in gene expression?

Accepted Answer

It is the site where RNA polymerase binds to initiate transcription

Question 17

A woman with blood type AB and a man with blood type O have a child. Which blood types are possible for their child?

Accepted Answer

A or B

Question 18

Which of the following best explains why sickle-cell anemia persists at high frequencies in some populations?

Accepted Answer

Heterozygotes have increased resistance to malaria

Question 19

Which of the following is a real-world application of gel electrophoresis?

Accepted Answer

Separating DNA fragments by size for forensic analysis

Question 20

A geneticist is mapping the relative positions of genes on a chromosome. Which tool is she most likely using?

Accepted Answer

Chromosome map

General Biology Study Guide: Genetics, Molecular Biology, Gene Regulation, Biotechnology, and Reproductive Anatomy

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