which of the following organelles is known as the cells digestion center

HESI RN

Biology Test

1. Which of the following organelles is known as the cell's digestion center?

A. Chloroplasts
B. Mitochondria
C. Lysosomes
D. Ribosomes

Correct answer: C

Rationale: The correct answer is C: Lysosomes. Lysosomes contain enzymes that break down waste materials and cellular debris within the cell, making them the cell's digestion center. Choice A, Chloroplasts, are responsible for photosynthesis. Choice B, Mitochondria, are the powerhouse of the cell, generating energy. Choice D, Ribosomes, are involved in protein synthesis. Therefore, Lysosomes are specifically known for their role in digestion within the cell.

2. 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.

3. Which of the following statements is true if a molecule exhibits adhesion?

A. Two molecules of the same substance have the ability to stay bonded to one another
B. The molecule has the ability to bond to or attract other molecules
C. A molecule has the ability to increase its heat when necessary
D. The molecule has the ability to form hydrogen bonds

Correct answer: B

Rationale: The correct statement is that if a molecule exhibits adhesion, it has the ability to bond to or attract other molecules. Adhesion refers to the ability of a molecule to bind to or attract different types of molecules. Choice A is incorrect because adhesion is about bonding to different molecules, not the same substance. Choice C is incorrect as adhesion does not relate to the ability of a molecule to increase its heat. Choice D is incorrect because forming hydrogen bonds is a specific type of interaction and not a general characteristic of molecules exhibiting adhesion.

4. What percentage of the offspring of the parents is predicted to have a cleft chin?

A. 25%
B. 50%
C. 0%
D. 75%

Correct answer: A

Rationale: When one parent carries the recessive gene for a cleft chin and the other does not, there is a 25% chance of the offspring inheriting the cleft chin. This is due to the fact that the trait follows a simple Mendelian inheritance pattern, where the offspring would need to inherit the recessive gene from both parents to express the trait. Therefore, 25% of the offspring are predicted to have a cleft chin. Choices B, C, and D are incorrect because the likelihood of inheriting a cleft chin in this specific scenario is 25%, not 50%, 0%, or 75%.

5. What are the nitrogenous bases of DNA?

A. Adenine, cytosine, guanine, and thymine
B. Adenine, guanine, and uracil
C. Adenine, guanine, and thymine
D. Adenine, cytosine, guanine, and uracil

Correct answer: A

Rationale: The correct answer is A: Adenine, cytosine, guanine, and thymine. These are the four nitrogenous bases found in DNA. Adenine pairs with thymine, and cytosine pairs with guanine, forming the complementary base pairs in the double helix structure of DNA. Choice B is incorrect because uracil is a nitrogenous base found in RNA, not DNA. Choice C is incorrect as it is missing cytosine, one of the four bases in DNA. Choice D is incorrect because uracil is not a nitrogenous base in DNA, and it also lacks thymine, which is essential for DNA structure.