OAT Biology 2 — Questions and Answers
Question 1: Which type of RNA carries amino acids to the ribosome during translation?
- mRNA
- rRNA
- tRNA (Correct answer)
- snRNA
Correct answer: tRNA
Transfer RNA (tRNA) carries specific amino acids to the ribosome, matching anticodons to mRNA codons.
Question 2: The sodium-potassium pump moves ions against their concentration gradients using:
- Facilitated diffusion
- ATP hydrolysis (Correct answer)
- Osmosis
- Passive transport
Correct answer: ATP hydrolysis
The Na⁺/K⁺-ATPase pump uses energy from ATP hydrolysis to move 3 Na⁺ out and 2 K⁺ in against their gradients.
Question 3: During meiosis II, what separates to produce haploid daughter cells?
- Homologous chromosomes
- Sister chromatids (Correct answer)
- Bivalents
- Tetrads
Correct answer: Sister chromatids
Meiosis II resembles mitosis; sister chromatids separate at the centromere to yield haploid cells.
Question 4: Which organelle is primarily responsible for modifying and sorting proteins destined for secretion?
- Smooth ER
- Rough ER
- Golgi apparatus (Correct answer)
- Lysosome
Correct answer: Golgi apparatus
The Golgi apparatus processes, packages, and sorts proteins received from the rough ER for secretion or intracellular use.
Question 5: A frameshift mutation caused by a single nucleotide deletion would MOST likely result in:
- A conservative amino acid change
- A premature stop codon only
- Altered amino acids from the deletion point onward (Correct answer)
- No change in the protein
Correct answer: Altered amino acids from the deletion point onward
Deleting one nucleotide shifts the reading frame, changing every codon downstream of the mutation.
Question 6: Which phase of mitosis is characterized by chromosomes aligning along the cell's equatorial plate?
- Prophase
- Anaphase
- Metaphase (Correct answer)
- Telophase
Correct answer: Metaphase
During metaphase, spindle fibers attach to kinetochores and align chromosomes at the metaphase plate.
Question 7: In a Hardy-Weinberg population, if the frequency of the recessive allele (q) is 0.3, what is the expected frequency of heterozygotes?
- 0.09
- 0.42 (Correct answer)
- 0.49
- 0.21
Correct answer: 0.42
Heterozygote frequency = 2pq = 2(0.7)(0.3) = 0.42.
OAT Biology 2
Which type of RNA carries amino acids to the ribosome during translation?