Nokea
Which type of cells make up the myelin sheaths?
- A. Glial cells.
- B. Dendrites.
- C. Melanocytes.
- D. Squamous cells.
Correct Answer: A
Rationale: The correct answer is A: Glial cells. Glial cells are responsible for producing the myelin sheaths that surround and insulate nerve cells in the central and peripheral nervous systems. Schwann cells in the peripheral nervous system and oligodendrocytes in the central nervous system are types of glial cells that form the myelin sheaths. Choice B, dendrites, are not involved in forming myelin sheaths; they are extensions of neurons that receive signals. Choice C, melanocytes, are cells responsible for producing melanin, not myelin. Choice D, squamous cells, are flat epithelial cells found in various tissues but are not involved in myelin sheath formation.
You may also like to solve these questions
When conducting a research study, which of the following is NOT a good reason for using a computer?
- A. A computer can be used to store and sort large quantities of data.
- B. Computers can interface with instruments and record data efficiently.
- C. Using a computer eliminates all subjectivity and potential bias from an experiment.
- D. A computer can perform complex calculations more quickly and accurately than a human can.
Correct Answer: C
Rationale: Using a computer does not eliminate all subjectivity and potential bias from an experiment. While computers can assist in data collection and analysis, the design and execution of the research study can still be influenced by subjectivity and bias introduced by researchers. Researchers need to recognize their potential biases and take measures to reduce them throughout the research process. Choice A is correct as computers are valuable for managing large datasets. Choice B is correct as computers can efficiently work with instruments and record data. Choice D is correct as computers excel in performing complex calculations faster and more accurately than humans.
How many tissue layers make up the uterus?
- A. One.
- B. Two.
- C. Three.
- D. Four.
Correct Answer: C
Rationale: The correct answer is C, 'Three.' The uterus is composed of three tissue layers: the endometrium, myometrium, and perimetrium. The endometrium is the innermost layer that thickens during the menstrual cycle and sheds during menstruation or supports a developing embryo during pregnancy. The myometrium is the middle layer, consisting of muscle tissue that contracts during labor. The perimetrium is the outer layer that covers the uterus. These three layers work together to support the functions of the uterus, such as menstruation, pregnancy, and labor. Choices A, B, and D are incorrect because the uterus is not made up of just one or two layers but rather three distinct tissue layers.
What is surgically altered during a vasectomy?
- A. Vas deferens
- B. Glans penis
- C. Prostate
- D. Urethra
Correct Answer: A
Rationale: During a vasectomy, the vas deferens is surgically altered or cut to prevent the transport of sperm from the testicles to the urethra. This procedure is a form of permanent male sterilization. The glans penis, prostate, and urethra are not surgically altered during a vasectomy. Therefore, the correct answer is the vas deferens (Choice A), as it is the structure specifically targeted and modified in this procedure. The glans penis (Choice B) is the sensitive tip of the penis, the prostate (Choice C) is a gland vital for semen production but not involved in a vasectomy, and the urethra (Choice D) is the tube that carries urine and semen but is not surgically altered in a vasectomy.
What is the process called in which a substance changes from a gas to a liquid?
- A. Condensation.
- B. Evaporation.
- C. Sublimation.
- D. Vaporization.
Correct Answer: A
Rationale: Condensation is indeed the correct answer. It is the process by which a substance changes from a gas to a liquid. This occurs when the temperature of a gas decreases enough for its particles to lose energy and come together to form a liquid. On the other hand, evaporation is the process of a liquid changing to a gas. Sublimation is the direct transition of a substance from a solid to a gas without passing through the liquid phase. Vaporization, on the other hand, is the general term for the process of a liquid changing to a gas, which includes both evaporation and boiling.
Are red hair and a height of six feet part of an individual's genotype or phenotype?
- A. Red hair is part of the phenotype; height is part of the genotype.
- B. Red hair is part of the genotype; height is part of the phenotype.
- C. Both characteristics describe his genotype.
- D. Both characteristics describe his phenotype.
Correct Answer: D
Rationale: In the context of genetics, genotype refers to an individual's genetic makeup, while phenotype refers to the observable characteristics resulting from the interaction of the genotype with the environment. Red hair and a height of six feet are observable characteristics, making them part of the individual's phenotype. Therefore, both red hair and height are aspects of the individual's phenotype. Choices A and B are incorrect as they incorrectly assign one characteristic to the genotype and the other to the phenotype, which is not accurate. Choice C is incorrect as it states that both characteristics describe the genotype, which is inaccurate as they are observable traits. The correct answer is D, as both red hair and height are observable traits or characteristics, falling under the definition of phenotype in genetics.