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. 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.

3. What do prokaryotic cells lack in comparison to eukaryotic cells?

A. A defined nucleus and a series of membrane-bound organelles
B. A defined nucleus and no membrane-bound organelles
C. No defined nucleus and a series of membrane-bound organelles
D. No defined nucleus and no membrane-bound organelles

Correct answer: D

Rationale: Prokaryotic cells are characterized by the absence of a defined nucleus and membrane-bound organelles. Choice A is incorrect because prokaryotic cells lack membrane-bound organelles. Choice B is incorrect because prokaryotic cells lack both a defined nucleus and membrane-bound organelles. Choice C is incorrect as prokaryotic cells have no defined nucleus. Therefore, the correct answer is D.

4. Which of the following is not true of mitosis?

A. Mitosis produces daughter cells
B. Mitosis has five main stages
C. Mitosis can only be done by haploids
D. Following mitosis, daughter cells are identical to parent cells

Correct answer: C

Rationale: The correct answer is C. Mitosis occurs in diploid cells and involves stages that result in the production of two identical daughter cells. Haploids do not undergo mitosis, as mitosis is a process specific to diploid cells. Choice A is true as mitosis does produce daughter cells. Choice B is incorrect as mitosis typically consists of four main stages: prophase, metaphase, anaphase, and telophase. Choice D is true, as one of the main outcomes of mitosis is the production of daughter cells that are genetically identical to the parent cell.

5. Which organelle has the ability to hydrolyze fats, nucleic acids, proteins, and sugars?

A. Chloroplasts
B. Mitochondria
C. Lysosomes
D. Ribosomes

Correct answer: C

Rationale: The correct answer is C, Lysosomes. Lysosomes contain hydrolytic enzymes that are capable of breaking down various biomolecules such as fats, nucleic acids, proteins, and sugars. This organelle acts as the 'digestive system' of the cell. Choices A, B, and D are incorrect because chloroplasts are involved in photosynthesis, mitochondria are responsible for energy production, and ribosomes are responsible for protein synthesis, not the hydrolysis of biomolecules.