1. What is the main function of calcitonin, a hormone produced by the thyroid gland?

A. Stimulate metabolism and heat production
B. Increase calcium absorption from the intestines
C. Enhance bone growth and development
D. Lower blood calcium levels

Correct answer: D

Rationale: The correct answer is D: 'Lower blood calcium levels.' Calcitonin is a hormone produced by the thyroid gland that helps regulate calcium levels in the blood. It works by inhibiting the breakdown of bone, which in turn lowers the amount of calcium released into the bloodstream. This process helps to decrease blood calcium levels when they are too high. Options A, B, and C are not functions of calcitonin; instead, they are more closely associated with other hormones such as thyroid hormones, vitamin D, and growth hormone, respectively.

2. A patient needs to take 2 tablets for every 30 pounds of body weight. If they weigh 150 pounds, how many tablets should they take?

A. 5
B. 10
C. 15
D. 20

Correct answer: A

Rationale: Divide the patient's weight (150 pounds) by the ratio denominator (30 pounds/tablet) to get 5 tablets.

3. The author expresses concern about the...

A. high cost and limited efficiency of traditional fossil fuel power plants.
B. unpredictable weather patterns and their impact on renewable energy production.
C. increasing dependence on technology and potential cybersecurity risks.
D. negative environmental consequences of renewable energy infrastructure.

Correct answer: B

Rationale: The passage's focus on managing the intermittency of renewable energy due to weather conditions implies concern about B.

4. What is the role of RNA in protein synthesis?

A. Stores genetic information
B. Decodes genetic information
C. Provides energy for the process
D. Transports amino acids to the ribosomes

Correct answer: B

Rationale: Rationale: RNA plays a crucial role in protein synthesis by decoding the genetic information stored in DNA and carrying it to the ribosomes where proteins are synthesized. This process involves transcription, where RNA is synthesized from DNA, and translation, where the information in RNA is used to assemble amino acids into proteins. RNA acts as a messenger between DNA and the ribosomes, ensuring that the correct sequence of amino acids is used to build proteins according to the genetic code. Therefore, option B is the most appropriate choice as it accurately describes the role of RNA in protein synthesis.

5. The process of a gas changing into a liquid is called:

A. Evaporation
B. Boiling
C. Condensation
D. Sublimation

Correct answer: C

Rationale: Condensation happens when gas particles lose energy and slow down, transitioning into the liquid state.

6. What is the difference between a homozygous recessive genotype and a homozygous dominant genotype?

A. Both have the same phenotype, but different genotypes.
B. Both have the same genotype, but different phenotypes.
C. Homozygous recessive has two dominant alleles, while homozygous dominant has two recessive alleles.
D. Homozygous recessive has two identical recessive alleles, while homozygous dominant has two identical dominant alleles.

Correct answer: D

Rationale: Rationale: - Homozygous recessive genotype refers to an individual having two identical recessive alleles for a particular gene (e.g., rr for a trait where r represents the recessive allele). - Homozygous dominant genotype refers to an individual having two identical dominant alleles for a particular gene (e.g., RR for a trait where R represents the dominant allele). - The difference between the two genotypes lies in the specific alleles present in each case, with homozygous recessive having two recessive alleles and homozygous dominant having two dominant alleles. - This genetic difference results in different phenotypes being expressed, as the dominant allele typically masks the expression of the recessive allele in heterozygous individuals.