Tham khảo tài liệu 'sat ii biology episode 2 part 5', ngoại ngữ, ngữ pháp tiếng anh phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | ANSWERS AND EXPLANATIONS 77. The correct answer is E . Primary consumers do not photosynthesize only producers carry out photosynthesis . Excretion provides some metabolic waste materials that can be utilized by detritivores and thus are not lost from the ecosystem. Energy that goes into the metabolism and growth of an organism contributes to the biomass of the organism and is subsequently passed on to the next higher trophic level. The energy used in respiration results in the production of inorganic molecules and heat it is largely lost from the flow of energy in the ecosystem. 78. The correct answer is E . The heritability of variation is a key component to the theory of natural selection and is necessary for evolution to occur. Those individuals that are most adapted to their environment are most likely to survive and successfully reproduce passing on favorable genes to their offspring. As long as the selection forces remain in place the number of individuals in the population with favorable genes will continue to increase possibly leading to the development of a new species after many generations. 79. The correct answer is A . 80. The correct answer is D . BIOLOGY-M TEST 81. The correct answer is C . In the DNA molecule base pairing occurs between adenine and thymine which are held together by two hydrogen bonds and base pairing occurs between guanine and cytosine which are held together by three hydrogen bonds. 82. The correct answer is D . Under normal conditions of DNA replication telomeres that are present on the end of each chromosome in eukaryotic cells become shorter and shorter with each cycle of replication. The length of the telomeres typically predetermines the life span of the cell by controlling the number of possible cycles of DNA replication. Telomerase an enzyme that catalyzes the lengthening of telomeres is not present in the cells of most multicellular organisms other than those giving rise to gametes. Telomerase has been found to occur in .
