1. What is the neurotransmitter involved in muscle movement?

A. Dopamine
B. Acetylcholine
C. Serotonin
D. GABA

Correct answer: B

Rationale: The correct answer is B: Acetylcholine. Acetylcholine is the neurotransmitter involved in muscle movement. It is released by motor neurons at the neuromuscular junction to stimulate muscle contraction. Dopamine is involved in reward and pleasure pathways in the brain, serotonin plays a role in mood regulation, and GABA is an inhibitory neurotransmitter that helps to reduce neural activity. Understanding the specific roles of neurotransmitters is crucial in grasping their functions in the nervous system.

2. What is the term for the particles moving around within a substance?

A. Ions
B. Atoms
C. Molecules
D. Kinetic energy

Correct answer: C

Rationale: In most cases, the particles moving within a substance are individual molecules or atoms, depending on the state of matter.

3. What is a lifestyle practice that can weaken the immune system?

A. Getting enough sleep
B. Eating a balanced diet rich in fruits and vegetables
C. Managing stress levels
D. Frequent smoking

Correct answer: D

Rationale: Frequent smoking is a lifestyle practice that can weaken the immune system. Smoking has been linked to various health issues, including suppressing the immune system's ability to fight off infections and diseases. The chemicals in tobacco smoke can impair immune function, making smokers more susceptible to illnesses. On the other hand, getting enough sleep, eating a balanced diet rich in fruits and vegetables, and managing stress levels are practices that support a healthy immune system, rather than weaken it.

4. A study finds a specific gene linked to increased risk of heart disease. Does this mean everyone with that gene will develop heart disease?

A. Yes, the gene deterministically causes heart disease.
B. No, other factors also influence heart disease risk.
C. We need more research to clarify the gene's exact role.
D. Only people with a family history of heart disease need to worry.

Correct answer: B

Rationale: The presence of a specific gene linked to an increased risk of heart disease does not guarantee that everyone with that gene will develop the condition. Other factors such as lifestyle, environment, and overall health also play a significant role in determining an individual's risk of heart disease. Therefore, it is essential to consider these additional factors rather than solely attributing the risk to the gene itself.

5. What is the significance of studying pedigrees in human genetics?

A. Predicting the exact outcome of genetic crosses in humans.
B. Tracing the inheritance of complex traits with multiple contributing genes.
C. Identifying carriers of dominant genetic disorders.
D. Determining the risk of acquiring a specific mutation de novo.

Correct answer: B

Rationale: Rationale: Pedigrees are diagrams that show the relationships within a family and can be used to track the inheritance patterns of specific traits or diseases. While pedigrees can provide information on the inheritance of single gene disorders (such as identifying carriers of dominant genetic disorders, as mentioned in option C), their primary significance lies in studying complex traits with multiple contributing genes. These traits do not follow simple Mendelian inheritance patterns and are influenced by both genetic and environmental factors. By analyzing pedigrees, researchers can identify patterns of inheritance for complex traits, such as polygenic diseases or traits influenced by gene-environment interactions. Therefore, option B is the most appropriate choice as it captures the main significance of studying pedigrees in human genetics.