A nucleus consists of a nuclear membrane that surrounds it, within the membrane there is a nucleolus which can be compared metaphorically to the yolk of an egg in appearance. The nucleolus is surrounded by nucleoplasm which is quite like the cytoplasm.
Answer:
true
Explanation:
<em><u>Some water pollution is caused from “point sources” that is discrete locations, from which pollutants are discharged, e.g., a pipe, ditch, ship, or factory smokestack. Point sources originate in large and easy to trace facilities, hence are easier to control. In contrast, pollution from “nonpoint” sources is cumulative, arising from multiple inputs over larger areas, such as farms, city streets, and residential neighbourhoods. Hence, such sources are harder to precisely identify, and because of this uncertainty, nonpoint source pollution is harder to control than the point source.</u></em>
The third one.……...................
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.
Once this initial energy is added, the wave travels through the medium until all its energy is transferred. In contrast, electromagnetic waves require no medium, but can still travel through one.
