Answer:
A.
Explanation:
Dark coloured moths will be better camouflaged and so better protected from predators. More of them will survive and reproduce, increasing the frequency of dark coloured genes.
Light coloured gene will provide less camouflage, those moths will be caught by predators more often and live to reproduce less. So the light coloured gene will decrease.
Answer:
The cells that make up the digestive, muscular, skeletal, reproductive, and excretory systems all need oxygen from the respiratory system to function, and the cells of the respiratory system as well as all the other system bneed nutrients and must get rid of metabolic wastes.
Explanation:
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.
