Nokea
Which of the following statements is NOT true about DNA?
- A. DNA contains the nucleotides A, T, C, G and is read 5' to 3'.
- B. DNA contains genetic information and is tightly coiled with proteins to form chromosomes.
- C. DNA contains the nucleotides A, T, C, G and is read 3' to 5'.
- D. DNA is a double-stranded molecule connected by hydrogen bonds.
Correct Answer: C
Rationale: The correct answer is C because DNA is typically read from the 5' end to the 3' end, not from 3' to 5'. Choices A, B, and D are all true statements about DNA. DNA contains the nucleotides A, T, C, G and is read in a 5' to 3' direction. DNA also contains genetic information and is tightly coiled with proteins to form chromosomes. Additionally, DNA is a double-stranded molecule connected by hydrogen bonds.
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Which of the following correctly orders the layers of the epidermis from most superficial to deepest?
- A. S. spinosum, S. basale, S. corneum, S. granulosum, S. lucidum
- B. S. corneum, S. lucidum, S. granulosum, S. spinosum, S. basale
- C. S. corneum, S. spinosum, S. basale, S. granulosum, S. lucidum
- D. S. basale, S. spinosum, S. granulosum, S. lucidum, S. corneum
Correct Answer: B
Rationale: The correct order of the layers of the epidermis from most superficial to deepest is: Stratum corneum, Stratum lucidum, Stratum granulosum, Stratum spinosum, Stratum basale. Choice B, 'S. corneum, S. lucidum, S. granulosum, S. spinosum, S. basale,' provides the accurate layering from the outermost to the innermost layer of the epidermis. Choice A is incorrect as it starts with Stratum spinosum, which is not the most superficial layer. Choice C is incorrect as it places Stratum spinosum before Stratum basale. Choice D is incorrect as it starts with Stratum basale, which is the deepest layer of the epidermis.
What does cytokinesis refer to?
- A. Division of the nucleus
- B. Division of the cytoplasm
- C. Separation of chromosomes
- D. Formation of spindle fibers
Correct Answer: B
Rationale: Cytokinesis refers to the division of the cytoplasm of a parental cell between two daughter cells during cell division. It ensures that each daughter cell receives its share of organelles and cytoplasmic components necessary for cellular functions. Choice A, division of the nucleus, is incorrect as this process is known as mitosis. Choice C, separation of chromosomes, is incorrect as it refers to the process of chromatid separation during mitosis. Choice D, formation of spindle fibers, is incorrect as spindle fibers are involved in mitosis to separate chromosomes, not in cytokinesis.
Which of the following organs is responsible for producing digestive enzymes?
- A. Liver
- B. Pancreas
- C. Gallbladder
- D. Esophagus
Correct Answer: B
Rationale: The correct answer is the Pancreas. The pancreas is an organ that produces digestive enzymes to aid in the breakdown of food in the small intestine. These enzymes play a crucial role in the digestion and absorption of nutrients from the food we eat. The liver is responsible for producing bile, not digestive enzymes. The gallbladder stores and concentrates bile produced by the liver, which aids in the digestion of fats. The esophagus is a muscular tube that helps in the movement of food from the mouth to the stomach and does not produce digestive enzymes.
Which of the following statements regarding macrophages is incorrect?
- A. They are found abundantly in the blood
- B. They are larger than neutrophils
- C. They are long-lived
- D. They are made in the bone marrow as monocytes, called macrophages once they reach organs
Correct Answer: A
Rationale: The correct answer is A. Macrophages are not found abundantly in the blood; they are present in tissues and organs. Macrophages are tissue-resident immune cells that play a key role in immune responses and are derived from monocytes produced in the bone marrow. Choice B is correct as macrophages are larger than neutrophils. Choice C is correct as macrophages are long-lived cells. Choice D is correct as macrophages originate in the bone marrow as monocytes and differentiate into macrophages once they migrate to various tissues and organs.
Which hormone is released by the ovaries to mature an egg?
- A. Estrogen
- B. Luteinizing Hormone
- C. Progesterone
- D. Testosterone
Correct Answer: A
Rationale: The correct answer is Estrogen (Choice A). Estrogen is produced by the ovaries and is essential for the maturation of eggs. It plays a crucial role in the development of secondary sexual characteristics, regulation of the menstrual cycle, and preparation of the uterus for implantation of a fertilized egg. Luteinizing Hormone (Choice B) is released by the pituitary gland and plays a role in ovulation, not the maturation of eggs. Progesterone (Choice C) is produced by the ovaries after ovulation and is important for preparing the uterus for pregnancy, not maturing eggs. Testosterone (Choice D) is a male sex hormone primarily produced in the testes, and while small amounts are also produced in the ovaries, it is not the hormone responsible for maturing eggs.