BS Bachelor of Science: Intro to Life Sciences 2

Question 1

Which organelle is primarily responsible for ATP production through cellular respiration in eukaryotic cells?

Accepted Answer

Mitochondria

Answer

Mitochondria carry out oxidative phosphorylation to produce the majority of a cell's ATP.

Question 2

During meiosis, crossing over (recombination) occurs between homologous chromosomes at which stage?

Accepted Answer

Prophase I

Answer

Crossing over occurs during Prophase I when homologous chromosomes form bivalents and exchange segments.

Question 3

Which type of bond holds the two strands of a DNA double helix together?

Accepted Answer

Hydrogen bonds

Answer

Hydrogen bonds between complementary base pairs (A-T and G-C) hold the two DNA strands together.

Question 4

A population of bacteria doubles every 20 minutes. Starting with 100 cells, approximately how many cells are present after 1 hour?

Accepted Answer

800

Answer

After 3 doublings (60 min ÷ 20 min), the population is 100 × 2³ = 800 cells.

Question 5

Which process converts light energy into chemical energy stored in glucose?

Accepted Answer

Photosynthesis

Answer

Photosynthesis uses light energy to synthesize glucose from CO₂ and water in chloroplasts.

BS - Bachelor of Science Practice Test