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)
The answers is all of the above
Answer:
Populations have variation in traits due to random mutation, crossing over and environmental conditions.
In my opinion, chloroplasts and mitochondria can't live outside the cell now because mitochondria ensure the energy for the cell and the chloroplasts is important for photosynthesis. Just my opinion.
Answer:
, electricity is just electrons (sub atomic particles) moving through a conductor. Light is also just subatomic particles moving through a conductor (1.e. transparent medium) and both are part of the electromagnetic spectrum.
