TextBook Solutions
- What is the role of the brain in reflex action? Reflex action occurs in spinal cord. The brain and spinal cord constitute the central nervous system. They receive information from all part... 2
- How do we detect the smell of an agarbatti (incense stick)? When agarbatti burns, it produces pleasant smell, which is detected by the olfactory receptor present inside the nose. The action of smell g... 1
- Which part of the brain maintains posture and equilibrium of the body? Cerebellum is a part of the brain maintains posture and equilibrium of the body 1
- What happens at the synapse between two neurons? The synapse is the tiny gap (not seen by naked eyes) between two adjacent neurons. This information, acquired at the end of the dendritic ti... 1
- What is the difference between reflex action and walking? Reflex action is involuntary action which means it is not under control of brain only involves spinal cord, it is rapid, thus gives instant... 1
- Compare the functioning of alveoli in the lungs and nephrons in the kidneys Alveoli Nephrons Structure Structure Alveoli are tiny balloon-like structures present inside the lungs. Nephrons are tubular structures pres... 1
- What are the differences between the transport of materials in xylem and phloem? Xylem Phloem Xylem tissue helps in the transport of water and minerals. Phloem tissue helps in the transport of food. Water is transported u... 1
- Describe double circulation in human beings. Why is it necessary? During a single cycle blood goes twice in the heart which is known as double circulation. It is necessary in human being to separate oxygena... 2
- What would be the consequences of a deficiency of haemoglobin in our bodies? Haemoglobin is the respiratory pigment that transports oxygen to the body cells for cellular respiration. Therefore, deficiency of haemoglob... 1
- How are the alveoli designed to maximise the exchange of gases? Alveoli provide a surface for the exchange of gases. An extensive network of blood vessels is present in the wall of the alveoli. By lifting... 1
- What are the differences between aerobic and anaerobic respiration? Name some organisms Aerobic respiration Anaerobic respiration It occurs in the presence of O₂. It occurs in the absence of O₂. It involves the exchange of gases... 1
- What are the necessary conditions for autotrophic nutrition and what are its by-products? Autotrophic nutrition takes place through the process of photosynthesis. Carbon dioxide, water, chlorophyll pigment, and sunlight are the ne... 1
- What is the role of saliva in the digestion of food? The role of saliva in the digestion of food: - It moistens the food for easy swallowing. - It contains a digestive enzyme called salivary am... 1
- How are fats digested in our bodies? Where does this process take place? Fats are present in the form of large globules in the small intestine. The small intestine receives the secretions from the liver and the pa... 1
- The breakdown of pyruvate to give carbon dioxide, water and energy takes place in (a) cytoplasm. Correct option is b) mitochondria. 2
- The autotrophic mode of nutrition requires (a) carbon dioxide and water. (b) chlorophyll. Correct option is d) all of the above. 2
- The xylem in plants are responsible for (a) transport of water. (b) transport of food Correct option is a) transport of water. 2
- The kidneys in human beings are a part of the system for (a) nutrition. Correct option is c) excretion. 2
- How is the amount of urine produced regulated? The amount of urine produced depends on the amount of excess water and dissolved wastes present in the body. Some other factors such as habi... 1
- What are the methods used by plants to get rid of excretory products? Plants can get rid of excess of water by transpiration. Waste materials may be stored in the cell vacuoles or as gum and resin, especially i... 1
- Describe the structure and functioning of nephrons. Nephrons are the basic filtering units of kidneys. Each kidney possesses large number of nephrons, approximately 1-1.5 million. The main com... 1
- How is food transported in plants? Phloem transports food materials from the leaves to different parts of the plant. The transportation of food in phloem is achieved by utiliz... 1
- How are water and minerals transported in plants? Water and minerals are transported through xylem cells from soil to the leaves. The xylem cells of roots stem and leaves are interconnected... 1
- What are the components of the transport system in highly organised plants? In highly organised plants, there are two different types of conducting tissues - xylem and phloem. Xylem conducts water and minerals obtain... 1