Answer the following :-
Q1. Plasma membrane is made up of which two components?
Answer:Plasma membrane is made up of lipids and proteins.
Q2. Cell wall is made up of which component?
Answer:Cell wall is made up of cellulose.
Q3. Give an example of unicellular organism.
Answer:Amoeba, Bacteria, Paramecium, Euglena, Protozoa.
Q4. Give an example of multicellular organism.
Answer:Fungi, plants, animals.
Q5. What is active transport?
Answer:The movement of molecules across a membrane in cells against a concentration gradient with the help of ATP units is called active transport.
Q6. What is the intracellular source of digestive enzyme?
Answer: Lysosome
Q7. What is endocytosis?
Answer: Endocytosis is the ingestion or engulfment of food and other material by folding of the plasma membrane. It is seen in Amoeba.
Q8. What is Protoplasm?
Answer:Protoplasm is the living substance of the cell. It includes both Cytoplasm and Nucleus.
Q9. Every multi-cellular organism has come from a single cell. How?
Answer: Cells divide to produce cells of their own kind. All cells thus come from pre-existing cells. For example-After fertilization, zygote is a single cell, but it multiply itself in many cells to become embryo. and after it become a baby.
Q10. How does the movement of substances take place into the cell? How do substances move out of the cell?
Answer:Some substances like carbon dioxide or oxygen can move across the cell membrane by a process called diffusion.For example, some substance like CO2 (which is cellular waste and requires to be excreted out by the cell) are present in high concentrations inside the cell. In the cell’s external environment, the concentration of CO2 is low as compared to that inside the cell. As soon as there is a difference of concentration of CO2 inside and outside a cell, CO2 moves out of the cell, from a region of high concentration, to a region of low concentration outside the cell by diffusion. Like CO2, all other substances move in and out of the cell in the same way. Water also obeys the law of diffusion. Water moves inside and outside of the cell by a type of diffusion called Osmosis.
Q11. What will happen if we put an animal cell or a plant cell into a solution of sugar or salt in water?
Answer:One of the following three things could happen:-
1) If the medium surrounding the cell has a higher water concentration in comparison with cell then the cell will gain water by osmosis, such a solution is known as hypotonic solution.
2) If the medium exactly the same water concentration as the cell then there will be no net movement across the osmosis,such a solution is known as isotonic solution.
3) If the medium has a lower concentration of water in comparison with the cell then the cell will lose water by osmosis solution, such a solution is known as hypertonic solution.
Q12. Can you think as to why the chromosome number has reduced to half in daughter cells?
Answer:The gametes are formed in the organisms with the help of meiotic divisions. There is reduction in the number of chromosomes to half in the daugter cells which are the gametes. The male and the female gamete are fused together to make up the total number of chromosomes in the individual. If there is no meiotic reduction, the number of chromosomes will be increased every time the next generation is produced.
Write full form of :-
1. ATP-Adenosine Triphosphate
2. PPLO- Pleuronpneumonia-like organism
3. DNA-Deoxyribonucleic acid
4. RNA-Ribonucleic acid
5. ER-Endoplasmic reticulum
6. RER-Rough Endoplasmic Reticulum
7. SER-Smooth Endoplasmic Reticulum
Post a Comment