Sand this is because It takes thousands of years for a rock to turn into sand
Most insects are herbivores in a stage of their life, but most of the time later on they because omnivorous (plant and meat eater) so therefore they don't stay herbivorous for long. Also, most herbivorous insects get eaten quite often.
Yes A is the correct answer
Answer:
New cells are naive to the infectious cells who attack it or they are not well prepared to deal with the different scenarios. But, the cells who are attacked before has the set or sequence of the viral or bacterial genome strand been identified by them, which leads to more safety or protection from these foreign bodies.
Explanation:
- Mechanism To attack a host cell:
The viruses and other infectious material enters and attacks the host cell, by breaching its membrane wall and installing or leaving a gene of its own inside the cell. Which then combines with the genome of the cell and it goes through the process of replication, translation etc,along with the host cell machinery. Which then spreads the specific gene strand more in the environment
- <u>Camouflage obtained by the infectious cell to hide it self:</u>
After the genome enters the host cell at first it does not recognizes the strands or foreign cells, as they cover there body with a camouflage sort of membrane and they look more like the body cells.
- <u>Reactions by the host cell and as a whole the body:</u>
The organisms detects the genome of the infections cells or strand, as they store the data about it in its server or database. As if the next time they were under attack then precautions will be there by the host cell to deal with it.
As for the cell who are never attacked before will be less safe to deal with these foreign bodies.
Answer:
The correct answer will be option-C
Explanation:
The rhythm of the heartbeat is controlled by the pacemaker of the heart called the sino-atrial node.
The SA node generates action potentials which trigger the contraction and relaxation of the atrium and ventricles. The membrane potential generation initiates by the depolarization of the cell membrane when the L type of Ca⁺² ions opens up and calcium ions enter the cell.
This depolarizes the cell until the potential threshold is reached which lies between the -40 and -30 mV.
Thus, Option-C is the correct answer.
