Answer
1. Answer: (b) plasmodesmata
Explanation: The cytoplasmic connection from cell to cell is known as plasmodesmata, while in animal cells it is known as gap junction.
2. Answer: (b) flagellin
Explanation:The bacterial flagellum is made up of the protein flagellin. Its shape is a 20-nanometer-thick hollow tube. It is helical and has a sharp bend just outside the outer membrane; this "hook" allows the axis of the helix to point directly away from the cell.
3. Answer: (d) Exosmosis
Explanation: Plasmolysis occurs due to Exosmosis in which the water molecules move from the region of higher concentration to the region of lower concentration of the cell around the surroundings through the cell membrane.
4. Answer: (b) Lysosome
Explanation:Lysosomes are called suicide sacks. They are produced by the Golgi body. They consist of a single membrane surrounding powerful digestive enzymes. It acts as the “garbage disposal” of the cell by breaking down cell components that are no longer needed as well as molecules or even bacteria that are ingested by the cell.
5. Answer: (c) Golgi apparatus
Explanation:Cell secretion is done by golgi apparatus. The external elimination of substances produced by the cell is known as cell secretion e.g., hormones, sweat, etc. Golgi apparatus is also known as the golgi complex.
6. Answer: (a) tonoplast
Explanation:The outermost covering of vacuole is called as tonoplast or vacuolar membrane. The tonoplast is the cytoplasmic membrane separating the vacuolar contents from the cell's cytoplasm.
7. Answer: (a) phospholipids
Explanation: The most abundant membrane lipids are the phospholipids. These have a polar head group and two hydrophobic hydrocarbon tails. The tails are usually fatty acids, and they can differ in length (they normally contain between 14 and 24 carbon atoms).
8. Answer: (a) steorids
Explanation:The smooth endoplasmic reticulum functions in many metabolic processes. It synthesizes lipids, phospholipids as in plasma membranes, and steroids. Cells that secrete these products, such as cells of the testes, ovaries, and skin oil glands, have an excess of smooth endoplasmic reticulum.
9. Answer: (a) Phospholipid
Explanation:It is a mosaic of molecules like lipids (primarily phospholipids), proteins, carbohydrate moiety and cholesterol.It suggests that the fluid nature of the plasma membrane is because of the phospholipids.Phospholipids of plasma membranes are amphipathic structures.
10. Answer: (a) numerical aperture
Explanation: Magnification of compound microscope is not connected with numerical aperature.
11. Answer: (d) X-rays crystallography
Explanation:X -rays crystallography is a technique which is used to study of binding protein on regulatory DNA sequence. In this technique, X-rays pass through a crystal of a substance and form a diffraction pattern.
12. Answer: (b) separation of DNA fragments according to their size
Explanation: Gel electrophoresis is a laboratory method used to separate mixtures of DNA, RNA, or proteins according to molecular size. In gel electrophoresis, the molecules to be separated are pushed by an electrical field through a gel that contains small pores.
13. Answer: (d) Oxidising enzyme (Oxidase)
Explanation: Peroxisomes contain at least 50 different enzymes, which are involved in a variety of biochemical pathways in different types of cells. Peroxisomes originally were defined as organelles that carry out oxidation reactions leading to the production of hydrogen peroxide.
14. Answer: (d) Granum
Explanation:The stacks or closely packed thylakoids is called granum. Chlorophyll is present inside the thylakoidsto perform photosynthesis in plant cells.
15. Answer: (d) Ribosomes
Explanation: 'Ribosome is an organelle which is found in both the type of cells that are eukaryotic and prokaryotic cells'. Note: They are located in two areas of cytoplasm.
16. Answer: (d) Elaioplast
Explanation: Plastids which store fats and oils are called as elaioplast. Elaioplasts are a type of leucoplast that is specialized for the storage of lipids in plants. Elaioplasts house oil body deposits as rounded plastoglobuli, which are essentially fat droplets.
17. Answer: (c) Acrocentric
Explanation:The centromere which is located near the end of the chromosome is called the Acrocentric chromosome. There are 5 pairs of acrocentric chromosomes in the human body. It is a sub-terminal centromere. The shape of the acrocentric chromosome is rod or i-shaped.
18. Answer: (a) Inclusion bodies
Explanation: Prokaryotes store food particles and other necessary stuffs in the form of granules called the inclusion bodies In eukaryotes usually these substances are stored in vacuole But since prokaryotes lack vacuole they store it in the form of inclusion bodies.
19. Answer: (b) Control their buoyancy
Explanation: Gas vacuoles are aggregates of hollow cylindrical structures called gas vesicles. They are located inside some bacteria .The inflation and deflation of the vesicles provides buoyancy, allowing the bacterium to float at a desired depth in the water. Bacteria that are known as cyanobacteria contain gas vacuoles.
20. Answer: (c) Phosphoglycerides
Explanation: The lipid component of the cell membrane mainly consists of phosphoglycerides.
21. Answer: (c) Glyoxysomes
Explanation: Glyoxysomes are specialized peroxisomes found in plants and mold, which help to convert stored lipids into carbohydrates so they can be used for plant growth.
22. Answer: (d) Mitochondria
Explanation: Mitochondria are pivotal in the control of apoptosis, being involved not only in the intrinsic but also in the extrinsic pathway.
23. Answer:(c) Nucleolus
Explanation: Molecules of rRNA are synthesized in a specialized region of the cell nucleus called the nucleolus, which appears as a dense area within the nucleus and contains the genes that encode rRNA.
24. Answer: (d) 9 + 2 pattern
Explanation: The flagellum and the cilia are composed of the microtubules. In the cilium, 9 peripheral doublets of microtubules are found which are known as the outer microtubules. The number of central microtubules in a cilium is two. This arrangement of the microtubules is called as the 9 + 2 pattern.
25. Answer: (d) chromatophores
Explanation: A cyanobacterium is having membranous extensions that are containing pigments that are known as chromatophores that are responsible for photosynthesis. The correct option is B i.e. chromatophores.
Click to practice Cell the Unit of Life MCQ Questions for Class 11