Answer no 1:
The part labelled A is the upper epidermis . The main function of the epidermis is to protect the structure of the leaf.
The part labelled B is palisade tissues. These are the sites where the chlorophyll are present.
The part labelled C are the air spaces in the spongy mesophyll tissue. They allow carbon dioxide to move freely.
The part labelled D are the vascular tissues which transport water and food.
Answer No 20:
The correct option is B) Most of the carbohydrates are made in the palisade mesophyll.
The palisade mesophyll comprises of chloroplast which are the sites where photosynthesis takes place. Hence, these will be the sites where carbohydrates will be manufactured.
Answer No 21)
The correct option is A) upper epidermis
As upper epidermis is the first layer of leaf, sunlight will enter through it and be trapped by the chlorophyll present in the palisade mesophyll cells.
Answer:
Its people would leave and migrate to other locations
Explanation:
Those areas where amount of precipitation having less than 8 inches, these areas are the arid regions. In these areas, water is present in very low amount which is not sufficient for the needs of high population. Minimum agricultural should be done because planting and growing of crops need a lot of water so most of the people migrate to other regions where water is present in large amount.
If a person comes in contact with this same virus years later, our body produces antibodies to get rid of or kill the virus
Explanation:
When a person is infected by a virus, the infected person's body develops antibodies as an immune response to act against the virus. Antibodies are produced as part of humoral immunity.
Antibodies work by neutralizing the viral activity, agglutination, phagocytosis or by complement system.
Antibodies are protein compounds which can recognize the invading pathogens and attack them.
Antigens or viral proteins in the virus leads to the production of antibodies in the host's body.
The specific antibodies triggers innate immune response upon detecting specific viral antigens when infected and will help the body to get rid of or kill the virus.