Most of the X-lined genes in humans are expressed in equal amounts between males and females because
A: only one of the two X chromosomes is active in each cell in the females.
B: X-linked genes on the X chromosome in males are expressed two-fold higher than in females.
C: only one X chromosome is kept after fertilization.
D: Half of the RNA transcripts from X chromosomes in female cells are degraded after transcription.
A: only one of the two X chromosomes is active in each cell in the females.
B: X-linked genes on the X chromosome in males are expressed two-fold higher than in females.
C: only one X chromosome is kept after fertilization.
D: Half of the RNA transcripts from X chromosomes in female cells are degraded after transcription.
举一反三
- Which is correct about the red-green colorblind in humans? A: loss of L or M cone genes on the X chromosome B: gain of S cone genes on the X chromosome C: loss of L or M cone genes on the Y chromosome D: gain of S cone genes on the Y chromosome
- The saying “men are from Mars and women are from Venus” correctly denotes that _________. A: males and females are different. B: males and females are similar. C: males and females are the same. D: males and females do not come from the Earth.
- If two genes from a parent cell are on the same chromosome, which of the following best explains why the daughter cells may not have the same alleles as the parent for both genes? A: they are linked genes B: they are unlinked genes C: crossing-over D: genetic mutation
- Linked<br/>genes are A: found<br/>on the same chromosome B: found<br/>in the same nucleus C: found<br/>only on sex chromosomes D: joined<br/>by a centromere
- Only this interval(区间) must be divided into two intervals, in one of which x is decreasing and in the other of which x is increasing.