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.
For plants , it's starch.
Answer:
A living organism's position in the flow of energy through an ecosystem.
The answer is B.) animals at the end of the food chain would not get enough food to stay alive.
Answer;
-Pure chemical substance and element
Explanation;
-Pure substances are substances that are made of only one type of atom or molecule.A pure substance can be either an element or a compound, but the composition of a pure substance doesn’t vary.
-An element is a pure substance that cannot be broken down into different types of substances by chemical means. All elements are pure substances. An element is composed of a single kind of atom. An atom is the smallest particle of an element that still has all the properties of the element.
-Tungsten is an element and therefore a pure substance.