HiSET Science: Life Science Practice Test 5 — Questions and Answers
Question 1: Which of the following is NOT a function of the skeletal system?
- Producing red blood cells in bone marrow
- Providing structural support for the body
- Regulating blood glucose levels (Correct answer)
- Protecting internal organs
Correct answer: Regulating blood glucose levels
Blood glucose regulation is a function of the endocrine system (insulin/glucagon), not the skeletal system.
Question 2: What happens during the light-dependent reactions of photosynthesis?
- CO2 is fixed into glucose using ATP and NADPH
- Oxygen is consumed and water is produced
- Light energy is used to split water and produce ATP and NADPH (Correct answer)
- Glucose is broken down to release energy
Correct answer: Light energy is used to split water and produce ATP and NADPH
Light-dependent reactions capture solar energy to split water molecules, releasing oxygen and producing ATP and NADPH for the Calvin cycle.
Question 3: A scientist discovers a new organism that has no nucleus, no membrane-bound organelles, and a single circular chromosome. This organism is best classified as:
- A eukaryote
- A prokaryote (Correct answer)
- A protist
- A fungus
Correct answer: A prokaryote
Prokaryotes lack a membrane-bound nucleus and organelles and typically have a single circular chromosome.
Question 4: Which hormone is responsible for stimulating the fight-or-flight response in the human body?
- Insulin
- Estrogen
- Adrenaline (epinephrine) (Correct answer)
- Thyroxine
Correct answer: Adrenaline (epinephrine)
Adrenaline (epinephrine) is released by the adrenal glands in response to stress, triggering increased heart rate, blood flow, and alertness.
Question 5: What evidence best supports the theory that all modern species share a common ancestor?
- All organisms live in similar environments
- All organisms share a nearly universal genetic code (DNA/RNA) (Correct answer)
- All organisms have the same number of chromosomes
- All organisms reproduce sexually
Correct answer: All organisms share a nearly universal genetic code (DNA/RNA)
The near-universal genetic code (DNA → RNA → protein) shared by all life strongly supports descent from a common ancestor.
Question 6: In an experiment, root tips are treated with a chemical that prevents spindle fiber formation. Which cellular process would be most directly disrupted?
- DNA replication
- Transcription
- Cell division (mitosis) (Correct answer)
- Protein synthesis
Correct answer: Cell division (mitosis)
Spindle fibers pull chromosomes apart during mitosis; without them, chromosomes cannot separate and cell division fails.
Question 7: Which of the following best explains why biodiversity is important for ecosystem stability?
- More species means more competition, reducing population sizes
- Diverse ecosystems have more redundancy, so the loss of one species has less overall impact (Correct answer)
- All species in an ecosystem perform identical functions
- High biodiversity always leads to faster energy transfer
Correct answer: Diverse ecosystems have more redundancy, so the loss of one species has less overall impact
Biodiversity provides functional redundancy — if one species disappears, others can fulfill similar roles, making the ecosystem more resilient.
HiSET Science: Life Science Practice Test 5
Which of the following is NOT a function of the skeletal system?