Answer:
The correct answer would be an option B.
Asexual reproduction is a reproduction in which offspring are produced from a single parent.
It does not involve fusion of gametes and crossing over due to which the offspring contain identical genome as that of parents.
This reduces the genetic diversity in a population due to which all the organisms of a population are at equal risk of extinction under unfavorable conditions such as high temperature, antibiotics, change in pH of surrounding medium et cetera.
Thus, the disadvantage of asexual reproduction is the lack of genetic diversity due to which a single antibiotic is able to kill millions of genetically identical bacteria.
Answer:
Option a. is correct
Explanation:
A mutation refers to a change in our DNA sequence which causes it to break down. It occurs due to the following reasons:
1. Due to mistakes when the DNA is copied
2. Due to environmental factors such as UV light, smoking.
3. Exposure to specific chemicals or radiation
The mechanism for reactive oxygen species to cause mutation is that bases are oxidized to a variety of different products which might pair with a different base than the original base would have.
One example can be the needle shaped leaves.
In desert areas, there are not much water sources. So basically, any drop of water is precious. To help prevent water loss of plants, for example cactus has very thin leaves that are needle shaped. Or some even don't have any leaves. This can reduce the surface area of leaves and thus reduce the water evaporating to the outer environment.
Another example also shown on cactus is that they have very thick waxy cuticle. It can also prevent water from evaporating from the stem. So that's why you see the stem is very shinny.
