(Q).
Q: Sexually reproducing organisms alternate between which stages? Read this paragraph and choose the correct option from the provided answers: CHAPTER SUMMARY 7.1 Sexual Reproduction Nearly all eukaryotes undergo sexual reproduction. The variation introduced into the reproductive cells by meiosis appears to be one of the advantages of sexual reproduction that has made it so successful. Meiosis and fertilization alternate in sexual life cycles. The process of meiosis produces genetically unique reproductive cells called gametes, which have half the number of chromosomes as the parent cell. Fertilization, the fusion of haploid gametes from two individuals, restores the diploid condition. Thus, sexually reproducing organisms alternate between haploid and diploid stages. However, the ways in which reproductive cells are produced and the timing between meiosis and fertilization vary greatly. There are three main categories of life cycles: diploid-dominant, demonstrated by most animals; haploid-dominant, demonstrated by all fungi and some algae; and alternation of generations, demonstrated by plants and some algae. Choices: - binary and diploid - binary and haploid - diploid and traploid - haploid and diploid A:
(A).
haploid and diploid

(Q).
Q: Blood enters the heart in what valve? Read this paragraph and choose the correct option from the provided answers: Blood flows in only one direction in the heart. Blood enters the atria, which contract and push blood into the ventricles. The atria relax and the ventricles fill with blood. Finally, the ventricles contract and push blood around the body. Choices: - tricuspid - aortic - mitral - atria A:
(A).
atria

(Q).
Q: What organism constitutes frothy green "pond scum"? Read this paragraph and choose the correct option from the provided answers: Polluted water can form a frothy green scum on the surface. This "pond scum" is actually a living organism, algae. The algae are plant-like protists. Usually the algae are too small to notice, but sometimes algae grow in excess because of the excess nutrients in polluted water. Choices: - bacteria - sponges - protozoa - algae A:
(A).
algae