Answer:
Explanation:
T cells are arguably the most important cells in immunity, as they are required for immune responses. They not only help activate B cells to secrete antibodies and macrophages to destroy ingested microbes, but they also help activate cytotoxic T cells to kill infected target cells. As dramatically demonstrated in AIDS patients, without helper T cells we cannot defend ourselves even against many microbes that are normally harmless.
Answer:
The addition and response to the net effect of postsynaptic potentials is called Spatial summation
Explanation:
Signal summation occurs when impulses received by a neuron are eummed together to reach the excitation threshold to fire a neuron. It occurs at the axon hillock of a neuron. Signal summation occurs since each neuron is connected to many other neurons, often receiving multiple impulses from them, both excitatory and inhibitory.
Signal summation can either be temporal or spatial.
Temporal summation, occurs when impulses received at the same place on the neuron in close temporal succession add up to initiate an action potential in the neuron.
Spatial summation occurs when impulses received simultaneously at different places on the neuron add up to initiate an action potential in the neuron.
Answer:
The correct answer is - Trains can have inconvenient schedules, but produce less pollution than cars do.
Explanation:
Trains are expensive to build and also required land for making routes and stations and platforms for passengers but that can be reimbursed by fare in a longer time period.
Trains also produce pollution but in comparison to cars these are way less contribute to the pollution, However, these are not convenient as they start and reach at a specific time and also sometimes not comfortable like cars.
Answer:
Mutation plays a vital part in evolution; it is the greatest source of genetic variation. In evolution, it creates a new DNA sequence for a particular gene, creating a new allele. Additionally, recombination can produce a DNA sequence (a new allele) for a specific gene through intragenic recombination.
Explanation:
Hope this helps!
