The stomata of leaves are surrounded by guard cells. The guard cells help the leaves to regulate the rate of transpiration of water from the leaves by opening and closing the stomata. When water enter the guard cells, they swell and bulge and this makes the stomata to open. So, with high water pressure, the guard cells will stimulate the stomata to open. The reverse will be the case if the water pressure is low.
Answer:
The phenotype is the result of the interaction between the genes (i.e., genotype) and environmental factors.
Explanation:
Cancer is a disease caused by abnormal expression of genes involved in the cell cycle, mitosis, DNA replication, etc. Moreover, the abnormal gene expression may be associated with environmental factors such as smoking, alcohol consumption, etc.
Natural selection leads to evolution because the strongest survive and pass on their genes
It is observed that the human population keep increasing significantly and it began to increase noticeably around 10,000 years ago.The greatest factor of this increase is the rapid development of the agricultures in lands, as well as the domestication of animals. These are the reasons why population increases at that time.
