which organelle is responsible for the synthesis of lipids and steroid hormones

HESI RN

Biology Test

1. Which organelle is responsible for the synthesis of lipids and steroid hormones?

A. Rough endoplasmic reticulum
B. Smooth endoplasmic reticulum
C. Golgi apparatus
D. Ribosomes

Correct answer: B

Rationale: The smooth endoplasmic reticulum is the correct organelle responsible for the synthesis of lipids, including phospholipids, cholesterol, and steroid hormones. The rough endoplasmic reticulum is primarily involved in protein synthesis and processing, making choice A incorrect. The Golgi apparatus is responsible for modifying, sorting, and packaging proteins and lipids for transportation, so it is not directly involved in lipid and steroid hormone synthesis, making choice C incorrect. Ribosomes are responsible for protein synthesis and are not involved in lipid or steroid hormone synthesis, making choice D incorrect.

2. Proteins are polymers of 20 molecules called:

A. Amino acids
B. Phospholipids
C. Carbohydrates
D. Fatty acids

Correct answer: A

Rationale: Proteins are indeed polymers made up of amino acids. Amino acids are the building blocks of proteins, where each protein has a unique sequence of amino acids that determines its structure and function. Phospholipids, carbohydrates, and fatty acids are not molecules that make up proteins. Phospholipids are the main components of cell membranes, carbohydrates are sugars used for energy and structural purposes, and fatty acids are building blocks of lipids.

3. Which of the following best describes phenotype?

A. The hereditary potentials and limitations of an individual
B. The genetic makeup of an individual organism
C. The entire complex of genes inherited from both parents
D. All the observable characteristics of an organism

Correct answer: D

Rationale: The correct answer is D: 'All the observable characteristics of an organism.' Phenotype refers to all the observable characteristics of an organism, such as physical appearance, behavior, and other traits, which result from the interaction of its genotype with the environment. Choice A is incorrect because it describes genotype. Choice B is incorrect as it defines genotype, not phenotype. Choice C is incorrect as it refers to the genotype, the genetic information inherited from both parents, rather than the observable traits.

4. Which of the following describes the set of metabolic reactions and processes that take place in the cells of organisms to convert biochemical energy from nutrients into adenosine triphosphate (ATP), and then release waste products?

A. Cellular respiration
B. Meiosis
C. Photosynthesis
D. Mitosis

Correct answer: A

Rationale: The correct answer is A: Cellular respiration. Cellular respiration is the process in cells that converts biochemical energy from nutrients into ATP and releases waste products. This process occurs in the mitochondria of the cell. Choice B, Meiosis, is a type of cell division that produces gametes with half the chromosome number. Choice C, Photosynthesis, is the process by which plants, algae, and some bacteria convert light energy into chemical energy to produce glucose. Choice D, Mitosis, is a type of cell division that results in two daughter cells with identical sets of chromosomes as the parent cell.

5. Protein synthesis begins with a process known as transcription. What is produced during this process?

A. A codon
B. A DNA helix
C. A DNA strand
D. An RNA strand

Correct answer: D

Rationale: The correct answer is D: An RNA strand. During transcription, the DNA template is used to produce an RNA strand, not a codon, DNA helix, or another DNA strand. A codon is a sequence of nucleotides that specifies a particular amino acid during translation, not produced during transcription. A DNA helix refers to the double-stranded structure of DNA, which is not produced during transcription. Another DNA strand is not produced during transcription since the process involves creating an RNA copy of a specific gene.