Organ: It is a group of tissues performing a specific function.<\/li>\n<\/ul>\nQuestion 14. \nDefine nucleus. What is its role? \nAnswer: \nThe central dense round body in the centre of the cell is called nucleus. In addition to its role in inheritance, nucleus acts as control centre of the activities of the cell.<\/p>\n
Question 15. \nDefine the term cytoplasm. \nAnswer: \nThe jelly-like substance found between the nucleus and the cell membrane is called cytoplasm.<\/p>\n
Cell Structure and Functions Class 8 Extra Questions Short Answer Type 2<\/h3>\n Question 1. \nHow do we observe the cell by microscope? \nAnswer: \nTo observe the cell by microscope, sometimes an organ has to be cut into sections to observe various smaller components. Some components in these sections are visible through the microscope after staining (dying) with coloured dyes.<\/p>\n
Question 2. \nWhat was the observation of a part of the bark of a tree (cork) by Robert Hooke? \nAnswer: \nRobert Hooke in 1665 observed slices of cork under a simple magnifying device. He took thin slices of cork and observed them under a microscope. He noticed partitioned boxes or compartments in the cork slice. These boxes appeared like a honey-comb. He coined the term cell for each box.<\/p>\n
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Question 3. \nDescribe the differences and similarities between cell and brick. \nAnswer: \nThe cells in the living organisms are arranged and appear like bricks in a building. Both bricks in the building and cells in the living organisms are basic structural units. The buildings, though built of similar bricks, have different designs, shapes and sizes. Similarly, in the living world, organisms differ from one another but all are made up of cells. But, cells in the living organisms are complex living structures unlike non-living bricks.<\/p>\n
Question 4. \nWhich part of the cell gives shape to it? \nAnswer: \nComponents of cells are enclosed in a membrane ealled cell membrane. This membrane provides shape to the cells in plants and animals. Cell wall is an additional covering over the cell membrane in plant cells. It gives shape and rigidity.<\/p>\n
Question 5. \nIs there any relation between the size of the body of the animal or plant with the size of the cell? \nAnswer: \nThe size of the cell, in fact, has no relation with the size of the body of the animal or plant. The size of the cell is related to its function. For example, nerve cells, both in the elephant and rat, are long and branched. They perform the same function of transferring messages in bigger as well as in the smaller organism.<\/p>\n
Question 6. \nHow do cells\/groups of cells perform different functions in multicellular organisms? \nAnswer: \nThe cell in a living organise is the basic structural unit. Cells combine to form tissues and a group of tissues is called an organ. These organs together constitute different systems in living beings and perform different functions. Each organ in the system performs different functions.<\/p>\n
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Question 7. \nWhat constitutes cytoplasm? \nAnswer: \nCytoplasm is a fluid present between the cell membrane and the nucleus and is made up of basic elements like carbon (C), hydrogen (H), oxygen (O) and nitrogen (N). These are found in the form of chemical substances like carbohydrates, proteins and water.<\/p>\n
Question 8. \nWhat are the components present in cytoplasm? \nAnswer: \nBesides nucleus, various other components-or organelles of cells are present in the cytoplasm. These are mitochondria, golgi bodies, ribosomes, etc. Cytoplasm, along with nucleus, forms the living substance of a cell. This living substance is called protoplasm.<\/p>\n
Question 9. \nWhat is nucleolus? Describe its function in brief. \nAnswer: \nNucleolus is a small, spherical, dense body in the nucleus. The function of nucleolus is to assemble ribosomes.<\/p>\n
Question 10. \nWhat are prokaryotic cells and eukaryotic cells ? \nAnswer: \nThe cells having nuclear material without nuclear membrane are termed prokaryotic cells. The organisms with these kinds of cells are called prokaryotes (pro = primitive; karyon = nucleus). Examples are bacteria and blue-green algae.<\/p>\n
The cells having a well-organised nucleus with a nuclear membrane are designated as eukaryotic cells. The organisms having these cells are called eukaryotes (eu = true; karyon = nucleus). Examples are onion, cells and cheek cells.<\/p>\n
Question 11. \nWhat is the function of nucleoplasm? \nAnswer: \nNucleoplasm of nucleus contains thread-like structures called chromosomes. These carry genes and help in inheritance.<\/p>\n
Cell Structure and Functions Class 8 Extra Questions Long Answer Type<\/h3>\n Question 1. \nDefine the function of following: \n(a) Plasma membrane \n(b) Mitochondria \n(e) Gene \n(d) Vacuole \n(e) Plastid<\/p>\n
Answer: \n(a) Plasma membrane: It is the outer covering of the cell which separates its contents from the surrounding medium. It is made up of lipids and protein. The main function of cell membrane is to regulate the movement of molecules in and out of the cell.<\/p>\n
(b) Mitochondria: Mitochondria are the powerhouses of the cell because energy is released from the mitochondria after respiration. They are the sites cellular respiration of or oxidation of food.<\/p>\n
(c) Gene: Genes carry information of heredity help in inheritance or transfer of characters from the parents to the offspring.<\/p>\n
(d) Vacuoles: Cells contain water-filled, sac-like structures called as vacuoles. They are large-sized in plant cells while either absent or small-sized in animal cells.<\/p>\n
(e) Plastids: The coloured bodies in the cytoplasm of the cells are called plastids. Plastids are found in plant cells only. Chloroplast i.e., the green plastids contains chlorophyll for the process of photosynthesis. Through this process, plant cell prepares food which is ultimately stored in the form of starch.<\/p>\n
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Question 2. \nWhat are the basic components of a cell? Describe their functions. \nAnswer: \nThe basic components of a cell are: \n(i) Cell membrane \n(ii) Cytoplasm \n(iii) Nucleus<\/p>\n
(i) Cell membrane separates the inside contents of the cell from outside. It being porous, allows movement of substances or materials both inwards and outwards of the cell. \n(ii) Cytoplasm contains the cell organelle, which performs different functions. \n(iii) Nucleus acts as a control centre of a cell. In addition to it, it also facilitates inheritance.<\/p>\n
Hope the knowledge provided regarding the Cell Structure and Functions Class 8 Extra Questions and Answers has helped you to the possible extent. For more info feel free to reach us and we will guide you at the earliest possibility. Stay connected to our site to avail latest updates on Extra Questions for Various Classes instantly.<\/p>\n","protected":false},"excerpt":{"rendered":"
Cell Structure and Functions Class 8 Extra Questions and Answers Science Chapter 8 PDF are solved by experts and will guide students in the right direction. Students can get how to tackle different questions easily by solving the Extra Questions for Class 8 Science Question bank on a regular basis. Class 8 Science Chapter 8 …<\/p>\n
Cell Structure and Functions Class 8 Extra Questions and Answers Science Chapter 8<\/span> Read More »<\/a><\/p>\n","protected":false},"author":9,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"default","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"default","adv-header-id-meta":"","stick-header-meta":"default","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","spay_email":""},"categories":[7],"tags":[],"yoast_head":"\nCell Structure and Functions Class 8 Extra Questions and Answers Science Chapter 8 - MCQ Questions<\/title>\n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n\t \n\t \n\t \n