All Free Biology MCQs with Answers
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19844 questions · page 661 of 1985
6601. The process of self-digestion of selective non functional organelle by cells through the actions of enzymes originating from the cell is called _.
- A. Pinocytosis
- B. Endocytosis
- C. Autophagy
- D. Cytotoxicity
Explanation: Autophagy is known as self-digestion, hydrolytic enzymes in lysosomes are responsible for it.
Correct answer: Autophagy6602. Glycophorin is involved in which of the following disease?
- A. Viral fever
- B. Common cold
- C. Asthma
- D. Malaria
Explanation: Glycophorins are heavily glycosylated sialoglycoproteins of human and animal erythrocytes. In humans, there are four glycophorins: A, B, C, and D. Glycophorins play an important role in the invasion of red blood cells (RBCs) by malaria parasites, which involves several ligands binding to RBC receptors. OPTIONS A, B, and C are incorrect.
Correct answer: Malaria6603. Which of the following parts of cell is described as fluid mosaic?
- A. Chloroplast
- B. Vacuole
- C. Cell membrane
- D. Endoplasmic reticulum
Explanation: Cell membrane describes the structure of the fluid mosaic model, in which fluid is a lipid bilayer and proteins float like icebergs in the sea.
Correct answer: Cell membrane6604. Which of the following modes of cellular transport requires energy?
- A. Active transport
- B. Osmosis
- C. Passive transport
- D. Diffusion
Explanation: Active transport requires energy all other do not require ATP for transport.
Correct answer: Active transport6605. The magnifying power of electron microscope as compared to the eye is?
- A. 500x
- B. 250,000x
- C. 500,000x
- D. 100,000x
Explanation: An electron microscope has a magnification from 100,000x to 300,000x.
Correct answer: 250,000x6606. The outer and inner membranes of mitochondria spindle are?
- A. Structurally and functionally different
- B. Structurally different but functionally similar
- C. Structurally and functionally similar
- D. Structurally similar but functionally different
Explanation: The outer membrane is a phospholipid bilayer consisting of porins. It separates the inside organelle from the rest of the cell and primarily transports nucleotides, ions, and metabolites between cytosol and the intermembrane space. It is also associated with the endoplasmic reticulum. (The outer membrane is similar to the plasma membrane in structure).The inner membrane has several folds called cristae. It is the site of an electron transport chain and produces ATP. This membrane is permeable to oxygen, carbon dioxide, and water only and acts as an electric insulator and chemical barrier. Thus the membranes of mitochondria are structurally and functionally dissimilar.
Correct answer: Structurally and functionally different6607. Ribosomes are tiny organisms, which are involved in the synthesis of:
- A. Protein
- B. RNA
- C. Nucleus
- D. Nucleosome
Explanation: Proteins are synthesized by ribosomes through a process called translation.
Correct answer: Protein6608. The soluble part of cytoplasm or fluid that remains when all organelles are removed is known as:
- A. Solution
- B. Gelatin material
- C. Cytoskeleton
- D. Cytosol
Explanation: Cytosol refers to the soluble, fluid portion of the cytoplasm that remains when all organelles are removed. It contains various molecules, ions, and enzymes necessary for cellular metabolism.
Correct answer: Cytosol6609. Which type of cell would be the most appropriate for thy study of chloroplast?
- A. Conducting cell
- B. Pericycle cell
- C. Photosynthetic cell
- D. All of these
Explanation: Photosynthetic cells contain chloroplasts in which chlorophyll is present.
Correct answer: Photosynthetic cell6610. Which of the following is not the function of endoplasmic reticulum?
- A. Transport of material
- B. Mechanical support
- C. Synthesis of conjugated molecules
- D. All of these
Explanation: ER is not involved in synthesis of conjugated molecules. Golgi apparatus does this.
Correct answer: Synthesis of conjugated molecules