Viva in Human Physiology Vidya Ratan
INDEX
×
Chapter Notes

Save Clear


The Cell1

Q. 1. Define Physiology.
Ans. Physiology is a branch of science dealing with normal functions of living organisms.
Q. 2. Define a cell.
Ans. A cell is a functional unit in the living matter, consisting of protoplasm surrounded by a cell membrane.
Q. 3. What is a cell membrane composed of?
Ans. A cell membrane is composed of protein and lipid molecules forming a semi-permeable membrane, which is actively selective in its functions.
Q. 4. Enumerate main functions of a cell membrane.
Ans. The cell membrane, actively and selectively, transports material across it; and is also protective in function.
Q. 5. What are the functions of mitochondria in a cell?
Ans. Mitochondria are concerned with tissue respiration and provision of energy (by ATP formation). These in a way act as power house of a cell.
Q. 6. What is the main role of ribosomes in a cell?
Ans. The ribosomes (endoplasmic reticulum) are mainly associated with synthesis of proteins.
Q. 7. What is the role of centriole in a cell?
Ans. The centriole serves to initiate the process of cell division.
Q. 8. What is Golgi apparatus (complex) concerned with?
Ans. The Golgi apparatus is concerned with secretory process.
Q. 9. What are Lysosomes?
Ans. Lysosomes are organelle formed by Golgi complex in the cell.
Q. 10. What is the function of Lysosomes?
Ans. These are associated with intracellular digestive system.2
Q. 11. The intracellular fluid has more sodium content than Potassium. Is this statement correct?
Ans. No, it is the other way around, i.e. intra-cellular fluid has more potassium content than sodium.
Q. 12. What is the main function of a nucleus?
Ans. The main function of a nucleus is division and propagation of cells.
Q. 13. What is chromatin?
Ans. Chromatin is fine thread-like structure composed of chromosomes found in the nucleus.
Q. 14. What is the number of chromosomes in somatic cells of human being?
Ans. There are 46 number of chromosomes, i.e. 22 pairs of somatic chromosomes and one pair of sex chromosomes.
Q. 15. Give a brief description of chromosome.
Ans. Chromosomes are fine thread-like structures forming the chromatin in the nucleus, and are made up of specific tiny structures called genes. The various hereditary peculiarities of the cell are passed on from one generation to another by the chromosomes through the genes of which the chromosomes are composed of.
Q. 16. What is the difference between mitotic and meiotic cell division?
Ans. In mitotic cell division the number of chromosomes remains the same, whereas in meiotic cell division the number of chromosomes is halved.
Q. 17. What is the structure of gene?
Ans. A gene is composed of a long double stranded DNA helix, surrounded by a protein helix.
Q. 18. What is DNA composed of?
Ans. DNA has phosphoric acid (deoxyribose) and four nitogenous bases, i.e. two purine (adenine and guanine) and two pyramidines (thymine and cystosine).
Q. 19. Name the various phases in mitotic division of a cell.
Ans. These are spireme phase, prophase, metaphase, cleavage stage, anaphase and telophase.3
Q. 20. What is a tissue?
Ans. A tissue is a collection of cells having similar structure and functions.
Q. 21. What are the main types of tissues in the body?
Ans. There are five main types of tissues in the body viz epithelial, connective, muscular, nervous tissue and the blood.
Q. 22. What is an epithelium?
Ans. An epithelium is a collection of cells having a covering tissue and separated from underlying connective tissue by a basement membrane, e.g. epithelial lining of skin, mucous membrane in oral cavity and secreting cells in glands. In liver, epithelia occur in clusters forming a solid mass.
Q. 23. What are the main types of epithelia in the body?
Ans. There are three main types of epithelia in the body, viz squamous as simple, stratified or transitional epithelia, columnar or glandular epithelia and ciliated (columnar) epithelia.
Q. 24. What are the main functions of epithelia?
Ans. There are two functions of epithelia viz protective and secretary functions.
Q. 25. Name the various connective tissues.
Ans. These are areolar tissue, fibrous, yellow elastic, reticular, adipose, lymphoid tissue; cartilage, bone and teeth.
Q. 26. Define homeostasis.
Ans. Homeostasis is a process of maintaining constant normal conditions in the internal environment of the body to enable its optimum normal functioning.
Q. 27. What do you understand by internal environment of the body?
Ans. Extracellular fluid surrounding the body cells is also termed as internal environment of the body.