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.
Answer: Weathering constantly changes the earth's surface by wearing away exposed surfaces, smoothing rough areas of rocks and causing rock materials to break down in time. Weathering creates soil and happens due to ice, wind, water, salt, acids and changes in temperature Gravity shapes the Earth's surface by moving weathered material from a higher place to a lower one.
Answer:
A. It saves energy for the organism to produce fewer chromosomes.
B. Asexual reproduction requires fewer chromosomes than sexual
reproduction
C. If it did not, the chromosome number would double in each
generation
D. Organisms reproduce sexually by joining two tetrads together.