Answer:
sugar
Explanation:
The sides of the stepping stool are made of rotating sugar and phosphate particles. The sugar is deoxyribose. The rungs of the stepping stool are sets of 4 sorts of nitrogen bases. Two of the bases are purines-adenine and guanine.
Organisms compete for the resources they need to survive- air, water, food, and space. In areas where these are sufficient, organisms live in comfortable co-existence, and in areas where resources are abundant, the ecosystem boasts high species richness.
Rounded, Rod-like & Spiral
Answer:
Reinforcement is the process by which natural selection increases reproductive isolation. Reinforcement can occur as follows: When two populations which have been kept apart, come back into contact, the reproductive isolation between them might be complete or incomplete. If it is complete, speciation has occurred.
Explanation:
<3
Answer:
Because of the chemical and structural nature of the phospholipid lipid by layer the lipid soluble molecule can just pass the lipid membrane and some small molecules can also pass freely.
Explanation:
as we know that the homeostasis is an important process for a living cell to maintain it self so for the the exchange of materials between the external and internal environment is must so for that it exchange material with the outside environment of the cell.as the cell membrane is semipermeable(mean allow some molecule to pass(lipid soluble) and not others(lipid non soluble) to pass through the membrane.the cell membrane is selectively permeable due to its nature and chemical composition the chemical composition is lipid and phosphate and glycerol(head) with fatty acid that may b saturated or unsaturated(tail).so finally all those molecule which are polar can not pass through the membrane and non polar can pass the membrane.The size of the molecule is also a factor on which the permeability depends.
