Extra Questions For Class 9 Science Chapter 5 Fundamental Unit of Life
Very Short Answer Type Questions (One Mark Each)
Q.1. Name the scientist who discovered cell.
AnswerAns. Robert Hooke discovered cell in 1665.
Q.2. Who discovered nucleus ?
AnswerAns. Robert Brown discovered nucleus.
Q.3. Who coined the term protoplasm ?
AnswerAns. J.E. Purkinje coined the term protoplasm.
Q.4. Name the scientists, who presented cell theory.
AnswerAns. M. Schleiden and T. Schwann independently proposed cell theory.
Q.5. Who suggested that all cells arise from pre-existing cells ?
AnswerAns. Virchow in 1855 suggested that all cells arise from pre-existing cells.
Q.6. Who discovered Golgi apparatus ?
AnswerAns. Camillo Golgi discovered Golgi apparatus.
Q.7. Identify the single celled organisms from the following:
cockroach, chlamydomonas, snake, mosquito, bacteria.
AnswerAns. From the above listed organisms chlamydomonas and bacteria are unicellular single called organism.
Q.8. Give the expanded form of ATP.
AnswerAns. Adenosine tri phosphate is the expanded form of ATP.
Q.9. Name an organism that feeds by endocytosis method.
AnswerAns. Amoeba is an organism that feeds by endocytosis method.
Q.10. Name the plastid which stores starch, oils and protein granules.
AnswerAns. Leucoplast are colourless plastids that stores starch, oils and protein granules.
Q.11. Define protoplasm.
AnswerAns. All the living contents of cell inside cell membrane constitute protoplasm. It includes cytoplasm and nucleus.
Q.12. Name two semi autonomous organelles.
AnswerAns. Mitochondria and chloroplast are two semi autonomous organelles which can manufactures their own proteins with the help of its own DNA and RNA.
Q.13. Which organelle is involved in the conversion of green brinjal to violet?
AnswerAns. Chromoplast are the coloured plastids that facilitate conversion of green brinjal into violet.
Q.14. Which nuclear component change into chromosome ?
AnswerAns. Chromatin – a granular network in the nucleoplasm that condenses to form long thin thread like chromosomes.
Q.15. Name the two nucleic acid present in the cell.
AnswerAns. DNA (De-oxyribose nucleic acid) RNA (Ribose nucleic acid) are the two nucleic acid present in the cell.
Q.16. Where genes are located ?
AnswerAns. Genes are the hereditary units which are located on the chromosomes.
Q.17. Name the substance of which genes are made up of.
AnswerAns. Genes are made up of segments of DNA.
Q.18. Name the chemical found in the walls of bark of tree?
AnswerAns. Suberin is the chemical found in the walls of bark of a tree.
Q.19. What are cisternae ?
AnswerAns. Cisternae are tubular structures arranged parallel to each other in stacks and have inflated ends. They are part of golgi apparatus.
Q.20. Which cell organelle give rise to lysosome ?
AnswerAns. Golgi bodies pinch off vesicles on the sides as well as maturing or trans face of the apparatus. These vesicles contain hydrolytic enzymes and are referred as lysosomes.
Q:21. Which cell organelle carry oxidative reactions including removal of toxic substances?
AnswerAns. Peroxisomes are the cell organelle that carry out oxidative reactions as well as aids in removal of toxic substances.
Q.22. Which cell organelle is known as ‘Power plant’ or ‘Powerhouse’ of cell?
AnswerAns. Mitochondria is known as the powerhouse of the cell.
Q.23. What are cristae and what is its significance ?
AnswerAns. Cristae are the infoldings of inner mitochondrial membrane. These infoldings create a large surface area for the chemical reactions generating ATP.
Q.24. Name the cell organelle which are exclusively found in plant cell.
AnswerAns. Plastids and cell wall are exclusively found in plant cell.
Q.25. Name the cell organelle exclusively found in animal cell.
AnswerAns. Centrosome is the cell organelle exclusively found in animal cell.
Q.26. In which chemical form energy is stored in our body ?
AnswerAns. ATP (Adenosine Triphosphate) is the energy currency of our cells and body.
Q.27. Chlorophyll pigment is found in which cell organelle ?
AnswerAns. Chloroplasts are the organelle that contains green chlorophyll pigment.
Q.28. Define nucleoid.
AnswerAns. Nuclear material of prokaryotes is nucleoid not bounded by nuclear envelope. It does not have nucleolus and is referred as nucleoid.
Q.29. What happens if ribosomes are removed from cells ?
AnswerAns. Proteins would not be synthesised if ribosomes are removed from the cell.
Q.30. What is nature of tonoplast ?
AnswerAns. Tonoplast is the membrane that bounds vacuole. Its chemical composition is similar to plasma membrane i.e., made up of proteins and lipids.
Q.31. What will happen to a plant cell if it is kept in a hypotonic solution ?
AnswerAns. Plant cell will swell up due to entry of water by the process of endo osmosis when placed in a hypotonic solution.
Q.32. What will happen to an animal cell if it is kept in hypertonic solution?
AnswerAns. If an animal cell is placed in a hypertonic solution then it loses water by exosmosis and forms a star like appearances. This phenomenon is called as crenation.
Q.33. Which cell organelle detoxify poisons and drugs in liver of vertebrates ?
AnswerAns. SER (Smooth Endoplasmic Reticulum) aids in detoxification of poison and drugs in the liver of vertebrates.
Q.34. If we sprinkle salt on cucumber slices after sometime it releases water. What mechanism is responsible for this ?
AnswerAns. Exosmosis is the movement of water molecules from a region of low solute concentration i.e., inside the cells of cucumber as compared to the external environment through a semipermeable membrane that takes place on adding salt to cucumber slices.
Q.35. Why is a cell membrane called a selectively permeable membrane?
AnswerAns. The cell membrane is called selectively permeable as it only allows specific molecules to pass. Only specific molecules like water and gaseous molecules can pass through the cell membrane directly. It stops the flow of other molecules towards the two sides.
Q.36. What would happen to the life of a cell if there was no Golgi apparatus?
AnswerAns. (1) The proteins in cells would float randomly if there were no Golgi bodies. Without the substances that the Golgi body typically distributes, other cells and organs in the body would not operate as they should.
(2) Lysosomes would not be generated in the absence of the Golgi apparatus, and the cell would eventually die as a result of the buildup of dead and damaged molecules and organelles.
(3) Materials would no longer be packaged or transported if the Golgi apparatus were absent. The cell’s secretory functions would also stop.
(4) Acrosome production cannot occur without the Golgi apparatus.
Q.37. where are proteins synthesised inside the cell
Ribosomes are the site of protein synthesis inside a cell. They are either free or attached to Rough Endoplasmic Reticulum (RER).
Q.38. Why are lysosomes known as suicide bag?
If the cell gets damaged, then one of the lysosomes bursts and release some digestive enzymes. The released enzymes then digest their own cell and ultimately the cell dies. Hence, lysosomes are called suicide bags of the cell.
Q.39. Can you name the two organelles we have studied that contain their own genetic material?
Mitochondria and chloroplasts
Q.40. Make a comparison and write down ways in which plant cells are different from animal cells.
|PLANT CELL||ANIMAL CELL|
|A. Have a cell wall.||A. Have no cell Have wall.|
|B. Nucleus is on side of cell.||B. Nucleus is in center on cell.|
|C. Have large vacuoles.||C. Have only small vacuoles.|
|D. Have regular in shape.||D. Often irregular in shape.|
|E. Has plasmodesmata.||E. Has no plasmodesmata.|
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