which structure is responsible for organizing protein synthesis

HESI A2

HESI A2 Practice Test Biology

1. Which organelle is responsible for organizing protein synthesis?

A. Nucleus
B. Ribosome
C. Lysosome
D. Vacuole

Correct answer: B

Rationale: The correct answer is B: Ribosome. Ribosomes are responsible for organizing protein synthesis by assembling amino acids. They are the cellular machinery where proteins are synthesized. The other choices, such as the nucleus, lysosome, and vacuole, do not directly participate in protein synthesis. The nucleus contains DNA and controls cell activities, the lysosome is involved in digestion and waste removal, and the vacuole is responsible for storage and maintaining cell turgor pressure.

2. Ocean waves may tear sponges into pieces, each of which may grow into a new sponge. What is this form of reproduction called?

A. Budding
B. Vegetative propagation
C. Binary fission
D. Fragmentation

Correct answer: D

Rationale: Fragmentation is the form of asexual reproduction where an organism breaks into fragments, and each fragment can grow into a new individual. In the case of sponges being torn into pieces by ocean waves, each piece has the potential to develop into a new sponge, making fragmentation the correct answer in this scenario. Budding is a form of asexual reproduction where a new organism develops as an outgrowth from the parent organism. Vegetative propagation involves the growth of new individuals from plant parts like stems or roots. Binary fission is a method of reproduction seen in some single-celled organisms where one cell divides into two identical cells.

3. The mixture of gases surrounding a planet is referred to as its ______.

A. Atmosphere
B. Stratosphere
C. Biosphere
D. Troposphere

Correct answer: A

Rationale: The mixture of gases surrounding a planet is referred to as its atmosphere. The atmosphere plays a crucial role in supporting life on Earth by providing oxygen, regulating carbon dioxide levels, and shielding the planet from harmful radiation. While the stratosphere, troposphere, and other layers are part of the atmosphere, the term 'atmosphere' encompasses the entire gaseous envelope surrounding a planet. The stratosphere, troposphere, mesosphere, thermosphere, and exosphere are specific layers within the atmosphere, each with distinct characteristics and functions.

4. How many bones are included in the human skeletal system?

A. 412
B. 103
C. Over 300
D. 206

Correct answer: D

Rationale: There are 206 bones in the human skeletal system. This includes bones in the skull, spine, ribs, arms, legs, hands, and feet. The correct answer is 206 because that is the standard number of bones in an adult human body. Choices A, B, and C are incorrect as they do not reflect the accurate count of bones in the human skeletal system.

5. During which phase is the chromosome number reduced from diploid to haploid?

A. S phase
B. interphase
C. mitosis
D. meiosis I

Correct answer: D

Rationale: The correct answer is 'meiosis I.' During meiosis I, the chromosome number is reduced from diploid to haploid through two rounds of division. Choice A ('S phase') is incorrect as the S phase is part of the cell cycle where DNA is replicated. Choice B ('interphase') is also incorrect as interphase is the phase where the cell prepares for division. Choice C ('mitosis') is incorrect as mitosis is a process where a diploid cell divides to produce two identical diploid daughter cells, maintaining the chromosome number.