CSET CSET Subtest II Life Sciences 5 — Questions and Answers
Question 1: Which process produces the most ATP per molecule of glucose during aerobic respiration?
- Glycolysis
- Pyruvate oxidation
- The citric acid cycle
- Oxidative phosphorylation (Correct answer)
Correct answer: Oxidative phosphorylation
Oxidative phosphorylation via the electron transport chain produces approximately 32–34 of the ~36–38 ATP per glucose.
Question 2: What term describes the movement of a substance from an area of lower concentration to higher concentration, requiring energy?
- Osmosis
- Facilitated diffusion
- Active transport (Correct answer)
- Simple diffusion
Correct answer: Active transport
Active transport uses ATP to move substances against their concentration gradient across a membrane.
Question 3: In the nitrogen cycle, which bacteria convert atmospheric nitrogen (N₂) into ammonia (NH₃)?
- Nitrifying bacteria
- Denitrifying bacteria
- Nitrogen-fixing bacteria (Correct answer)
- Decomposing bacteria
Correct answer: Nitrogen-fixing bacteria
Nitrogen-fixing bacteria (e.g., Rhizobium) convert inert N₂ gas into ammonia, making nitrogen available to plants.
Question 4: Which type of RNA carries amino acids to the ribosome during translation?
- mRNA
- rRNA
- tRNA (Correct answer)
- snRNA
Correct answer: tRNA
Transfer RNA (tRNA) has an anticodon that matches mRNA codons and carries the corresponding amino acid to the ribosome.
Question 5: A species found only in one specific location on Earth is described as which of the following?
- Invasive
- Endangered
- Endemic (Correct answer)
- Keystone
Correct answer: Endemic
An endemic species is native to and restricted to a particular geographic area and found nowhere else naturally.
Question 6: Which part of the brain regulates heart rate, breathing, and blood pressure as autonomic functions?
- Cerebellum
- Medulla oblongata (Correct answer)
- Cerebral cortex
- Hypothalamus
Correct answer: Medulla oblongata
The medulla oblongata contains vital autonomic centers that control heartbeat, respiration, and blood pressure.
Question 7: Which of the following best describes the role of enzymes in biological reactions?
- They increase the activation energy needed for reactions
- They are consumed during the reaction and must be replenished
- They lower the activation energy, speeding up reactions without being consumed (Correct answer)
- They change the overall free energy of the reaction
Correct answer: They lower the activation energy, speeding up reactions without being consumed
Enzymes are biological catalysts that lower activation energy and are not consumed, so they can catalyze many reaction cycles.
CSET CSET Subtest II Life Sciences 5
Which process produces the most ATP per molecule of glucose during aerobic respiration?