Answer: B
Explanation:
The T helper cell needs to acttivate the T cyctotoxic cell in order for the Tc cell to go do its work.
Once the TC cell is active it interacts with MHC-1 proteins on the surface of the infected host cell, this allows the Tc cell to recignise the host cell and begin secreting cytotoxins (perforins and granzymes) in order to degrade the infected cell and cause apoptosis (controlled cell death)
Answer:
<h3>plant has cell wall but animals don't have </h3>
Nitrogen fixation is a process in which nitrogen (N2) in the Earth's atmosphere is converted into ammonia (NH3). Atmospheric nitrogen or molecular dinitrogen (N2) is relatively inert: it does not easily react with other chemicals to form new compounds.
I would say the best option is "A". The climate in the arctic is full of snow, which is also white. It helps the arctic fox and snowshoe rabbit to hide. I didn't say inter species competition because they aren't competing for the same resource. (rabbit, vegetarian; fox, carnivore)
I hope this helps you!
Brainliest answer is always appreciated!
