遗传学双语教学试卷 9.docVIP

GENETICS FINAL EXAMINATION 8 1. Meiotic cell division produces haploid gametic cells by ___DNA replication and _____ cell division(s). a. 1 1 b. 1 2 c. 2 1 d. 2 1 e. none of these is correct 2. Microscopic chromosome preparations are usually done at mitotic metaphase. At this stage each chromosome is composed of___ DNA molecules and _______ chromatids. a. 1 1 b. 2 4 c. 4 4 d. 2 2 e. 1 4 3. The BLENDING THEORY of inheritance and MENDELS PARTICULATE THEORY often predict different progeny phenotypes. Consider Rufus-Goofus syndrome. If we assume that it is the result of one gene and affected individuals are homozygous recessive, the children of a homozygous normal and Rufus-Goofus syndrome parent are expected to be phenotypically normal carriers under the Mendelian model. The blending inheritance model predicts that these children will a. be normal. b. be affected with Rufus-Goofus syndrome. c. have mild cases of Rufus-Goofus syndrome. d. be severley affected. e. move to Minnesota 4. If we follow meiosis in a diploid heterozygote, the two alleles are, following the first cell division, a. together on a chromatid b. present only as mutants c. segretated into separate cells d. still linked e. present on one chromatid 5. Humans have 23 pairs of homologous chromosomes; chimps have 24 pairs of homologous chromosomes. Assume that a man and a male chimp make a bet about which of them can produce more genetically different sperm, at least in theory. Further assume that both are heterozygous at one locus on each chromosome. The________ will win. a. gorilla b. chimp c. man d. fish 6. Ten years after the Avery et al experiment which identified DNA as the genetic material was reported Watson and Crick used model building and the data of other workers to propose a double helical