Question

Here are data from crossing a phenotypically wild-type female Drosophila (tly) F1 The Y and A genes are dosely linked on the same chromosome. In this cross, which of the following is true about the gametes produced by the F1 progeny 2 pt YYAA X Yaa YyAa A. YA & Ya gametes will outnumber YA & ya gametes. B. YA & ya gametes will outnumber yA & Ya gametes. C.YA. Ya, YA, & xa gametes will be present in equal numbers. D. YA, Ya, yA & ya will be present in the ratio 9:3.3.1 12 pt total The following statement applies to question 9, 10 and 11: You are studying a diploid organism where 2n=8; How many chromatids would this cell have in G phase? (1 et A4 C. 16 D. 32 E. 64 How many chromosomes will a gamete from this organism have? (1 A4 B. 8 C. 16 D. 32 E 64 B.8 10. ) How many chromatids will a cell from this organism have in metaphase of meiosis 1?(1) B. 8 C. 16 D. 32E 64

Answer 1

8) According to Thomas Hunt Morgan, YA & ya gametes will outnumber yA & Ya gametes. Hence the answer is "B". Ga phase Number of chromatids would diploid cell have in are - 8 Reason 2n=8 In G, each chromosome is a single chromatid. Hence the answer is "B". 4 chromosomes will a gamete from déploid have. Because the no. of chromosomes in this organism Hence the answer is "A". organism is 8. (11) Each chromosome contain 2 chromatids. Therefore, if n=8 Number of chromatids is = 8x2 = 16 Meiois Meisos I is reduction vision, it means daughter cell have half number of chromosomes as compare to parent cell Number of chromosomes after meinis I is 4 Number of chromatids are 4x2 = 8 Hence the answer is "B".