Growth factors are hormones, proteins, or steroid molecules that regulate many cellular functions. They can stimulate the cell division by giving the signal to the cell to progress in the cell cycle.
<u>Explanation</u>:
Growth factors are naturally produced within the body and travels through the body to bind to their receptors present on their target cells. These growth factors are capable of signalling the cell to divide, proliferate, or heel. Their main aim is to signal or tell other cell when to do and what to do. Due to the binding with the receptors the growth factors activates specific genes.
Gametes or sex cells.considered as haploid because they having a single set of impaired chromosomes.
so letter A,
Biological Weathering<span>Biological weathering would include the effect of animals and plants on the landscape. This is more than roots digging in and wedging rocks. Biological weathering is the actual molecular breakdown of minerals. There are things called </span>lichens<span> (combinations of fungi and algae) which live on rocks. Lichens slowly eat away at the surface of rocks. The amount of biological activity that breaks down minerals depends on how much life is in that area. You might find more activities like lichens near oceans where the air is humid and cooler. </span>
Answer:
The correct answer is A. The larynx moves up against epiglottis when food is swallowed to prevent passage of food into it.
Explanation:
The epiglottis is a moist, cartilaginous structure that is part of the cartilaginous skeleton of the larynx. It also marks the boundary between the oropharynx and the laryngopharynx. The epiglottis obstructs the passage of the bolus at the time of swallowing preventing it from going to the respiratory system.
Larynx closure occurs when the vestibular and vocal folds approach the midline during swallowing. Occasionally, when you eat very fast, solid foods or liquids can enter the larynx.
Answer:
4
Explanation:
This is the answer because I have tested it and got it correct. As oxygen-rich (and carbon dioxide-poor) blood travels by a cell the oxygen diffuses through the cell membrane to the area of lower concentration inside the cell. It can do this easily because the oxygen molecule (O2) is very small and has no charge or polarity. The oxygen is used up rapidly by mitochondria.