Vary in the number of neutrons but Sama in the number if protons are called isotopes
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.
Pectinate muscles are parallel ridges in the walls of the atria of the heart. The name is due to their resemblance to the teeth of a comb (pecten). The heart is the organ pumps blood to all parts of the body. It is made up of four chambers, that is, right and left ventricles, left and right atria, and the blood vessels, Pulmonary artery, pulmonary vein, aorta, and venacava. An auricles are pouch like structure that increase the total filling capacity of the atrium and also increase the volume of blood that an atrium is able to contain.
D - the chipmunk population would likely continue to increase