Your cart is empty.
Practice each question, then open the answer or worked solution.
The kidneys in human beings are a part of the system for
Ans: (c) The kidneys in human beings are a part of the system for excretion. They are the organs that help in the excretion and removal of waste materials from the body through the regulation of urine.
The xylem in plants is responsible for
Ans: (a) The xylem in plants is responsible for the transport of water. The xylem tissues are the vascular or conducting tissues that help in the transport of water and minerals from the roots to various parts of the plant. These minerals and water are absorbed from the soil through the roots.
The autotrophic mode of nutrition requires
Ans: (d) The autotrophic mode of nutrition requires carbon dioxide, water, chlorophyll, and sunlight. Autotrophic nutrition is the process of making food by the organism itself. The food here is prepared by the process of photosynthesis which requires all the raw materials that are mentioned above.
The breakdown of pyruvate to give carbon dioxide, water, and energy takes place in
Ans: (b) The breakdown of pyruvate to give carbon dioxide, water, and energy takes place in mitochondria. This process is known as aerobic respiration where oxygen is required.
How are fats digested in our bodies? Where does this process take place?
Ans: Fats are present in the small intestine of our body in the form of large globules. The various juices from the liver (bile juice) and liver (pancreatic juice) are secreted in the small intestine. The bile salts that are released from the bile juice of the liver will help in breaking down the large fat globules into smaller globules so that the pancreatic enzymes (lipases) can easily act on them. The process of breaking down large fat globules into smaller fat droplets is termed emulsification.
What is the role of saliva in the digestion of food?
Ans: Saliva is a watery fluid that is secreted by the salivary glands present in the mouth. The functions of saliva start from the moistening of food that results in the formation of a food bolus, this food bolus can be easily swallowed and thus saliva helps in the process of digestion of food starting from the mouth. Saliva breaks down starch into maltose and dextrin with the help of an enzyme amylase present in it.
What are the necessary conditions for autotrophic nutrition and what are its by-products?
Ans: Autotrophic nutrition is the process where the organisms make their own food by themselves; this takes place through the process of photosynthesis. The necessary conditions that are required for autotrophic nutrition are the presence of sunlight along with raw materials that include carbon dioxide, water, and chlorophyll. The by-products of autotrophic nutrition are the carbohydrates in the form of glucose (food) and oxygen which are inhaled by animals.
$6{ CO }_{ 2 }+6{ H }_{ 2 }O\xrightarrow { Sunlight\quad Energy } { C }_{ 6 }{ H }_{ 12 }{ O }_{ 6 }+6{ O }_{ 2 }$
What are the differences between aerobic and anaerobic respiration? Name some organisms that use the anaerobic mode of respiration.
Ans: The differences between aerobic and anaerobic respiration are:
Aerobic Respiration | Anaerobic Respiration |
1) Aerobic respiration occurs in the presence of oxygen. | 1) Anaerobic respiration occurs in the absence of oxygen. |
2) In this process, glucose breakdown completely results in oxidation. | 2) In this process, the glucose molecule breaks down incompletely. |
3) carbon dioxide, water, and energy are released in the form of end products. | 3) The ethyl alcohol or lactic acid, carbon dioxide, and energy are formed as the end products. |
4) It takes place in both the plant and animal cells. | 4) It takes place in many anaerobic bacteria, yeast, and human muscle cells. |
How are the alveoli designed to maximize the exchange of gases?
Ans: Alveoli are the air sacs that are in the form of tiny pouches or sac-like structures present inside the lungs. They are in the form of balloon-like structures which increase the surface area for inhalation of air composed of blood capillaries. The alveoli present in the lungs are more than millions that increase the surface area of the lungs for the exchange of gases. Thus, a large amount of air is brought in contact with the air in the lungs; this maximizes the exchange of gases in the lungs.
What would be the consequences of a deficiency of hemoglobin in our bodies?
Ans: Haemoglobin is found in the red blood cell of the blood as the respiratory pigment that helps in the transportation of oxygen to the body cells for cellular respiration. Therefore, if the hemoglobin is deficient in the blood then it will affect the oxygen supplying capacity of blood resulting in the deficiency of oxygen in the body cells. This can also lead to anemia, an iron deficiency condition where the amount of blood in the body is quite less than required.