All Free Biology MCQs with Answers
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19844 questions · page 631 of 1985
6301. Which of the following structures is absent in higher plants and found in animal cells:
- A. Centriole
- B. Cytoskeleton
- C. Mitochondria
- D. Cytoplasm
Explanation: Centrioles assist in arranging microtubules to form the spindle fibers during chromosome segregation. In higher plant cells, microtubules can form spindle fibers without the help of centrioles.
Correct answer: Centriole6302. The outer membrane of the nuclear envelope is at places continuous with the:
- A. Golgi Apparatus
- B. Endoplasmic Reticulum
- C. Lysozomes
- D. Peroxisomes
Explanation: The outer nuclear membrane is continuous with the endoplasmic reticulum, so the space between the inner and outer nuclear membranes is directly connected with the lumen of the endoplasmic reticulum.
Correct answer: Endoplasmic Reticulum6303. Ribosomes in prokaryotes sediments at:
- A. 40S
- B. 70S
- C. 80S
- D. 60S
Explanation: All prokaryotes have the 70S (where S is the Svedberg unit used in ultracentrifugation) ribosomes while eukaryotes contain larger 80S ribosomes in their cytosol.
Correct answer: 70S6304. Which function is associated with lysosomes?
- A. Oxidative enzymes production
- B. Conversion of fatty acids to carbohydrates
- C. Phagocytosis
- D. Both "Conversion of fatty acids to carbohydrates" and "Phagocytosis"
Explanation: A lysosome is a membrane-bounded organelle that contains digestive enzymes. They are involved in intracellular digestion, the breakdown of excess or worn-out parts of cells, destroy invading viruses and bacteria, autophagy, and phagocytosis.
Correct answer: Phagocytosis6305. Among the following, which organelle has an outer membrane in it?
- A. Cell Membrane
- B. Mitochondria
- C. Lysosome
- D. Vacuole
Explanation: Mitochondria is an organelle that has a double membrane around it. The outer membrane surrounds the whole organelle. It has many protein-based pores that are big enough to allow the passage of ions and molecules. Inner membrane of mitochondria has Fo-F1 particles located towards the matrix side. Between the outer and inner layers, there is intermembrane space.
Correct answer: Mitochondria6306. Which one is correctly matched with the tail of a phospholipid?
- A. Hydrophilic
- B. Hydrophobic
- C. Light absorbing
- D. Porphyrin ring
Explanation: All of the lipid molecules in the cell membrane are amphipathic; that means that they have a hydrophillic(water-loving) or polar head and a hydrophobic (water-fearing) or non-polar tail.
Correct answer: Hydrophobic6307. Lipid bilayer makes the membrane differently permeable barrier that allows the transport of:
- A. lonic materials
- B. Polar materials
- C. Non-polar materials
- D. Glycoproteins
Explanation: Lipids,proteins and carbohydrates are responsible for functional diversity of the membranes. Lipid bilayer makes the membrane differentially permeable barrier that allows the transport of non-polar materials across it and prevents ionic materials.
Correct answer: Non-polar materials6308. The safranin stain is usable for:
- A. Fungal hyphae
- B. Cytoplasm/Cellulose
- C. Blood cells
- D. Lignin
Explanation: Safranin stain is usable for lignin in plant cells
Correct answer: Lignin6309. The layers of cellulose fiber in cell wall are arranged with each other at:
- A. Obtuse angle
- B. Parallel angle
- C. Right angle
- D. Horizontal angle
Explanation: Cellulose fibers are responsible for strengthening of cell wall of plants. They are arranged in a criss-cross manner and placing these fibers at right angles with each other gives more strength.
Correct answer: Right angle6310. Which cell organelle is incorrectly matched with its function?
- A. Chloroplast - carbon fixation
- B. Mitochondria - ATP synthesis
- C. Cell membrane - cell recognition
- D. Golgi apparatus - intracellular digestion
Explanation: Intracellular digestion is done by lysosomes and the Golgi apparatus plays an important role in lipid metabolism and modifying proteins.
Correct answer: Golgi apparatus - intracellular digestion