Question 1. What is phototropism?
Answer:
The stems, upper parts and leaves of plants move in the direction of light. This movement of plants is called phototropism.
Question 2. Define nutrition.
Answer:
The method of biological process in which nutrients are ingested and consumed by the organism is called nutrition.
Question 3. How is transmission of qualities from one generation to another?
Answer:
Through the process of reproduction, the ancestral qualities of an organism are transmitted to the offspring from generation to generation.
Question 4. What is the role of blood platelets in blood clotting?
Answer-
These are the smallest sized blood cells whose diameter is 2-3 micrometer. These are also called viruses or shrimbocytes. These are produced by megakaryocytes of the bone marrow. Their number in the blood is 2.5-3.5 × 105 /(mm)³ of blood. It helps in blood clotting.
Question 5. What do you understand by genetic quality?
Answer :- The rules of inheritance of traits in humans are based on the fact that both mother and father transfer equal amount of genetic material to the offspring. This means that every trait can be influenced by the father's and mother's DNA. Therefore, there will be two options for each trait in each offspring. Then which trait will be reflected in the child?
Question 6. What is the role of scavengers in the ecosystem?
Answer-
Ecosystem contains some microorganisms like bacteria, fungi and Dead bodies and waste materials of plants and animals are decomposed by protozoa. Hence they are called decomposers or decomposers. Such organisms decompose the complex organic substances present in the dead bodies and waste materials of plants and animals into inorganic elements. After decomposition, gaseous elements like nitrogen and oxygen are released into the atmosphere. Solid substances and liquids move into the soil. From where they merge into the hydrosphere. Such microorganisms (bacteria and fungi) have been called micro consumers or saprotrophs. The purified substances are again recycled by green plants.
Question 7. What is tissue culture? How is this accomplished?
Answer:-
Healthy desired plants are selected in tissue culture.Callus is formed by cutting a small piece of tissue and using artificial nutrients. With the help of hormones, this callus produces a young plant. The physical and genetic properties of the plant produced through tissue culture are completely similar to that of the parent. Plants produced by this method are called clones. This technique is generally used in the cultivation of ornamental plants.
Question 8. Write the reason for depletion of ozone layer.
Answer:
Scientists have studied the ozone level of the atmosphere andThe fact has emerged that the ozone level has declined rapidly and its level over Antarctica has become so low that it has been called the ozone hole. Through this the ultraviolet rays of the Sun are entering the Earth's atmosphere. Currently, it is a major topic of research by scientists globally. To find a suitable alternative to CFC so that the depletion of ozone level can be stopped. Aerosols, shaving foam, refrigeration coolants, etc. increase CFCs and cause ozone depletion.
