Nokea
Which organelle is responsible for storing genetic material?
- A. Mitochondria
- B. Nucleus
- C. Ribosome
- D. Endoplasmic reticulum
Correct Answer: B
Rationale: The correct answer is the Nucleus. The nucleus is responsible for storing genetic material (DNA) and controlling cell functions. Mitochondria are known for energy production, not genetic storage. Ribosomes are involved in protein synthesis, not genetic material storage. The endoplasmic reticulum is involved in protein and lipid synthesis, not genetic material storage. Therefore, the nucleus is the organelle primarily responsible for housing the genetic material within a cell.
You may also like to solve these questions
From which of the following germ layers does the nervous system develop?
- A. Ectoderm
- B. Endoderm
- C. Gastroderm
- D. Mesoderm
Correct Answer: A
Rationale: The correct answer is A: Ectoderm. The nervous system develops from the ectoderm, which is the outermost of the three germ layers. The ectoderm gives rise to structures such as the skin, hair, nails, and the entire nervous system. Choices B, C, and D are incorrect because the endoderm gives rise to the lining of the gut and associated organs, the gastroderm is not a recognized germ layer, and the mesoderm forms structures like muscles, bones, blood, and the circulatory system, but not the nervous system.
Which of the following meninges is a thin membrane containing numerous nerves and blood vessels that supply nourishment to the underlying brain cells and spinal cord?
- A. Arachnoid mater
- B. Dura mater
- C. Periosteum
- D. Pia mater
Correct Answer: D
Rationale: The pia mater is the correct answer. It is a thin, innermost layer of the meninges that contains numerous nerves and blood vessels, providing nourishment to the underlying brain cells and spinal cord. The arachnoid mater (Choice A) is the middle layer of the meninges and does not contain as many nerves and blood vessels as the pia mater. The dura mater (Choice B) is the tough, outermost layer of the meninges and is not responsible for supplying nourishment. The periosteum (Choice C) is a connective tissue membrane covering bones, not part of the meninges.
Which of the following are examples of positive correlation?
- A. As rainfall increases, plant stem length decreases.
- B. As rainfall increases, roots show longer length.
- C. When plotting a comparison of rainfall to plant length, the line trends to the lower right.
- D. When plotting a comparison of rainfall to plant length, the line trends to the upper right.
Correct Answer: D
Rationale: The correct answer is D. Positive correlation indicates that as one variable increases, the other variable also increases. In this case, when plotting a comparison of rainfall to plant length, if the line trends to the upper right, it shows a positive correlation where as rainfall increases, plant length also increases. Choices A, B, and C show either no correlation or negative correlation, as they describe scenarios where the variables move in different or opposite directions.
Which of the following antibodies can cross the placenta?
- A. IgA
- B. IgD
- C. IgG
- D. IgM
Correct Answer: C
Rationale: The correct answer is IgG. IgG is the only antibody that can cross the placenta, providing passive immunity to the developing fetus. IgA, IgD, and IgM do not cross the placenta. IgA is mainly found in mucosal secretions, IgD is involved in the activation of B cells, and IgM is the first antibody produced in response to an infection, but it does not cross the placental barrier.
Which of the following brain structures is responsible for emotions, emotional behavior, and motivation?
- A. Amygdala
- B. Cerebellum
- C. Hypothalamus
- D. Pons
Correct Answer: A
Rationale: The correct answer is the amygdala. The amygdala is a key brain structure involved in processing emotions, emotional behavior, and motivation. It plays a crucial role in fear responses, emotional memories, and social behaviors. The cerebellum (Choice B) is primarily responsible for coordination and balance, not emotions. The hypothalamus (Choice C) regulates basic survival functions like hunger, thirst, and body temperature, but it is not primarily responsible for emotions. The pons (Choice D) is involved in functions such as sleep, respiration, and bladder control, but it is not the main center for emotions, emotional behavior, or motivation.