Answer:e
retroviruses
Explanation:
Retroviruses appear to cause cancer in their host by mutating the host gene sequences allowing for the activation of some potentially oncogenic genes to be expressed. They do this by inserting their proviral DNA into the host genome at specific regulatory sequences deregulating cellular signaling and transcriptional controls.
B is not true
Hope this helps!
Guard cells. They surround the stomata and become turgid to close the opening.
Brightly colored peacocks mate more frequently than drab peacocks is an example of Sexual selection.
Sexual selection is the "advantage which certain individuals have over other individuals of the same sex and species solely in respect of reproduction".
Some points about Sexual selection:-
- it's a mode of natural selection.
- concept was first introduced by Charles Darwin.
- called it as second agency of selection.
- natural selection is based on the struggle to survive but sexual selection is struggle to reproduce.
- it produce sexual dimorphism in second sexual characters.
- two types of sexual selection are:
a) intrasexual selection - in between same sex. it is also known as mate competition. Here two or males compete for each other.
b) intersexual selection - known as femal mate choice. Here females choose their sexual partner.
7. Some examples are Antlers in deer, feathers of peacock, comb of chicken.
Female peacock or peahens prefer to mate with males that have large and colourfull tails, to maximise their chance of reproductive sucess. This process is simply known as Sexual selection.
Learn more about Sexual selection here:
brainly.com/question/24233253
#SPJ4