In general, yes, the dorsal blood vessel of a worm be seen from the worm's exterior because a worm's "skin" is very thin. Although of course there are exceptions.
A mutation is a change in trait. For example people who are lactose intolerant are normal, but people that can can drink milk without a problem have mutated. Hopefully this makes sense and helped.
DNA replicated through a complex process. Many enzymes such as polymerase are involved in making new copies of DNA and transferring it to mRNA.
The cell membrane<span> is semipermeable, meaning that only certain molecules and </span>substances<span> can pass through </span><span>the cell membrane.;
Hope this helps :))</span>
<u>Answer:</u>
The main function of the ozone layer is to block most of the sun's damaging rays from reaching Earth.
Option: (b)
<u>Explanation:</u>
- The stratosphere containing high level of ozone molecules about 30 km to 50 km altitude helps to absorb the sun's ultra violate rays.
- In its absence, it would be very difficult for anything to survive. Plants cannot live and grow as the UV light causes weakening of plants.
- It causes skin cancers. The increase in UV flux will lead to increase in sunburn, blindness, cataract, causing potentially death of animals and plants.
