All Free Biology MCQs with Answers
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19844 questions · page 690 of 1985
6891. When viewed through an electron microscope, which structure is surrounded by a double membrane?
- A. Endoplasmic reticulum
- B. Golgi body
- C. Mitochondrion
- D. Ribosome
Explanation: A mitochondrion is a double membrane-bounded organelle. The outer mitochondrial membrane is smooth, while the inner membrane has infoldings called cristae.
Correct answer: Mitochondrion6892. Which of the following has both cytoplasm and cell wall?
- A. Muscle cells
- B. Red blood cells
- C. Root hair cells
- D. Xylem vessels
Explanation: Root hair cells are plant cells. They have cytoplasm as well as cell wall as their outermost boundary.
Correct answer: Root hair cells6893. Which structures are found in both animal cells and plant cells?
- A. Cell membrane and chloroplasts
- B. Cell membrane and nucleus
- C. Cell wall and chloroplasts
- D. Cell wall and nucleus
Explanation: Cell membrane and nucleus are found in all eukaryotic cells, including plant and animal cells. On the other hand, cell wall and chloroplasts are only found in plant cells.
Correct answer: Cell membrane and nucleus6894. Which organelle is not correctly paired with its cellular function?
- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: Storage of carbohydrate is not the function of ER. ER is involved in the synthesis of proteins, lipid metabolism, detoxification of harmful chemicals, and providing mechanical support to the cell.
Correct answer: Option A6895. Which one of the following organelles always contains DNA?
- A. Centriole
- B. Golgi apparatus
- C. Lysosome
- D. Mitochondrion
Explanation: Mitochondrion contains its own circular DNA and 70S ribosomes.
Correct answer: Mitochondrion6896. Which one of the following would exocrine cells be expected to contain as a result of their function?
- A. Increased number of golgi apparatus
- B. Increased amounts of rough endoplasmic reticulum
- C. Both A and B
- D. None
Explanation: Exocrine cells have secretory function so an increased activity of such cells means increase in number of proteins or other secretions which are formed by ribosomes attached to RER.
Correct answer: Both A and B6897. The nuclei of both plant and animal cells contain one or more dense bodies known as nucleoli. Which one of the following correctly describes the function of nucleoli?
- A. The formation of new DNA molecules
- B. The organization of the spindle during nuclear division
- C. The replication of mitochondria following nuclear division
- D. The formation of ribosomes
Explanation: Nucleolus is the factory of ribosomes so it is involved in the formation of ribosomes.
Correct answer: The formation of ribosomes6898. The diagram shows the components that can be seen with an electron microscope in a mitochondrion. Which of the following shows the correct labelling?
- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: The parts of mitochondria are as follows: Outer membrane - Inner membrane - Cristae - Matrix - Intermembrane space.
Correct answer: Option A6899. When radioactively-labelled amino acids are taken up by pancreatic acinar (secretory) cells, what is the sequence of structures in which radioactivity will appear? (first → last)
- A. Cytoplasm, endoplasmic reticulum, Golgi apparatus
- B. Cytoplasm, lysosomes, endoplasmic reticulum,
- C. Lysosomes, nucleus Golgi apparatus
- D. Membrane cytoplasm, nucleus
Explanation: "The explanation for this question will be added soon!".
Correct answer: Cytoplasm, endoplasmic reticulum, Golgi apparatus6900. The diagram shows the ultrastructure of a cell. In which cell component is a new synthesized protein modified by adding carbohydrate?
- A. 5
- B. 4
- C. 6
- D. 2
Explanation: 2 represents golgi apparatus. The most important function of this apparatus is to modify the proteins and lipids by adding carbohydrates and converting them into glycoproteins or glycolipids.
Correct answer: 2