Nokea
What cell structure is responsible for efficiently packaging DNA into a small volume to fit into the nucleus of a cell and protect the DNA structure and sequence?
- A. Golgi apparatus
- B. Chromatin
- C. Smooth endoplasmic reticulum
- D. Mitochondria
Correct Answer: B
Rationale: Chromatin is the correct answer. Chromatin is responsible for packaging DNA into a more compact, dense structure to fit into the nucleus and protect the DNA. The Golgi apparatus is involved in processing and packaging proteins, not DNA. Smooth endoplasmic reticulum is involved in lipid metabolism and detoxification. Mitochondria are known as the powerhouse of the cell responsible for energy production, not DNA packaging.
You may also like to solve these questions
At the beginning of meiosis, how many chromosomes does the diploid parent cell have?
- A. 23
- B. 24
- C. 46
- D. 54
Correct Answer: C
Rationale: The correct answer is C: 46. At the start of meiosis, the diploid parent cell contains 46 chromosomes. During meiosis, the number of chromosomes is halved, resulting in each gamete having 23 chromosomes. Choice A (23) is incorrect because that is the number of chromosomes in a human gamete, not the parent cell. Choice B (24) and Choice D (54) are also incorrect as they do not reflect the correct number of chromosomes in a diploid parent cell at the beginning of meiosis.
Binary fission is a type of asexual reproduction. Which of the following occurs during the binary fission process?
- A. The chromosomes bind to the plasma membrane
- B. The chromosomes attach to the spindle formed along the axis
- C. The chromosomes gather in the center of the cell
- D. The chromosomes begin to separate
Correct Answer: A
Rationale: The correct answer is A. In binary fission, the chromosomes bind to the plasma membrane before the cell splits into two. This initial step ensures that each daughter cell receives a complete set of genetic material. Choice B is incorrect because the spindle apparatus is characteristic of eukaryotic cell division (mitosis), not prokaryotic binary fission. Choice C is incorrect as chromosomes do not necessarily gather in the center of the cell during binary fission. Choice D is incorrect because the chromosomes do not begin to separate in binary fission; they replicate and then move to opposite ends of the cell before division.
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.
A molecule's specific heat is the amount of heat necessary to raise the temperature of 1 gram of that molecule by:
- A. One degree Celsius
- B. Five degrees Celsius
- C. Two degrees Celsius
- D. Four degrees Celsius
Correct Answer: A
Rationale: The correct answer is A: 'One degree Celsius.' Specific heat is defined as the amount of heat required to raise the temperature of one gram of a substance by one degree Celsius. This property is specific to each substance and is used in various calculations involving heat and temperature changes. Choices B, C, and D are incorrect because specific heat is always measured per one degree Celsius increase in temperature for one gram of the substance, not five degrees, two degrees, or four degrees.
Which of the following options correctly lists the five stages of mitosis in order from beginning to end?
- A. Prophase, Prometaphase, Telophase, Metaphase, Anaphase
- B. Prophase, Prometaphase, Metaphase, Anaphase, Telophase
- C. Metaphase, Anaphase, Prophase, Prometaphase, Telophase
- D. Metaphase, Telophase, Anaphase, Prophase, Prometaphase
Correct Answer: B
Rationale: The correct order of the stages of mitosis is Prophase, Prometaphase, Metaphase, Anaphase, and Telophase. Choice A is incorrect because it has Anaphase and Metaphase in the wrong order. Choice C is incorrect as it starts with Metaphase, which is not the first stage of mitosis. Choice D is incorrect as it also has the stages in the wrong order, and it starts with Metaphase, which is incorrect.