There are many different categories of t-cells that carry out various roles for the immune system. differentiation for most t-cells occurs during the t-cell maturation, but some differentiation occurs after maturation following antigen presentation. one category of t-cells functions in antigen presentation and activation of b cells, as well as the activation of cytotoxic t-cells and macrophages. what is this category of t-cell? a) t b) memory t c) regulatory t d) natural killer t

The answer is A.)Helper T cells

Explanation:

I got this question on USA Test Prep and this was the right answer. Hope this helps!

answer: - few nutrients

high pressure

low temperatures

explanation: 1. few nutrients:   open-ocean zone is located way far from the land, which is the main source of the essential nutrients.2. high pressure: pressure increases by 1 atmosphere for every 10 meters increase in depth.3. ample sunlight: a large fraction of the sunlight is reflected back to the atmosphere from the sea surface. 4. varying salinity: below the thermocline, the water is isolated from the atmosphere so the salinity remains stable over the year.5. low temperatures:   the temperature of open-ocean zone ranges from a low of -2°c to an average of 17°c

interphase   is the cell cycle stage in which the cell acquires nutrients, creates and uses proteins and other molecules and starts the process of cell division by replicating the dna. it is the longest stage in the eukaryote cell cycle.

the following   can go wrong during interphase:   a base pair could be mismatched during the duplication process causing a mutation.   correct answer: c

explanation: