D or a those are the best questions..............XD this question though! anyways see yah later and maybe a brainly?
Answer:
Hemoglobin.pulmonary artery.
Explanation:
1. about hemoglobin.Hemoglobin is the protein inside red blood cells. It carries oxygen.
2. about pulmonary artery.The pulmonary artery is a big artery that comes from the heart. It splits into two main branches, and brings blood from the heart to the lungs. At the lungs, the blood picks up oxygen and drops off carbon dioxide. The blood then returns to the heart through the pulmonary veins.
3. There exist a concentration difference of carbon dioxide and oxygen inside the alveoli and capillaries due to which the diffusion of the two gases takes place. The carbon dioxide moves from the blood to the alveoli sac and the oxygen moves from the sacs to the blood.
An allele is like a trait or a specific gene.
Answer:
temporal reproductive isolation
Explanation:
The correct answer would be temporal reproductive isolation.
<u>Reproductive isolation</u> generally refers to series of biological mechanisms or processes that prevent members of different species from mating/fertilization or prevent the product of their mating to be invalid.
Some reproductive isolation processes prevent members of different species from mating or prevent fertilization as a result of mating. These processes are known as pre-zygotic reproductive isolation mechanisms.
Some other processes ensure that the product of fertilization (when it occurs) is invalid. These are known as post-zygotic isolation mechanisms.
<em>A good example of the pre-zygotic reproductive isolation process is </em><em>when closely related by different species bloom at different times</em><em>. This will prevent mating or cross-pollination to happen between the different species. This is known as temporal reproductive isolation.</em>
<h2>It contains toxins</h2><h2>It killed off bird populations.</h2><h2>It caused harm to human populations.</h2>
Explanation:
Let us understand the term DDT
DDT : Dichlorodiphenyltrichloroethane
- This is a crystalline chemical compound
- Basically used for protecting insects eating crops
- It is colorless, odorless, tasteless
- Initially used as pesticides
It killed off bird populations: Though it does not kill birds directly by consuming, it has indirectly damaged the egg by making the egg's shell too thin which gets broken easily.
It controlled diseases like malaria: Since this option talks about positive attribute of DDT, this option stands invalid. This chemical compound controls mosquitoes attacking the crop.
It caused harm to human populations: DDT causes vomiting, tremors or shakiness, and seizures
It contained toxins: It contains moderate toxins.
