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
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
举一反三
- Which is correct about the red-green colorblind in humans? A: (A) loss of L or M cone genes on the X chromosome B: (B) gain of S cone genes on the X chromosome C: (C) loss of L or M cone genes on the Y chromosome D: (D) gain of S cone genes on the Y chromosome
- 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
- 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 complete set of genes of a given species<br/>called ( ) A: genome B: gene C: DNA D: chromosome cDNA
- The exfoliative toxins, TSST-1, and the enterotoxins are all superantigens. The genes for these toxins are A: Present in all strains of Staphylococcus aureus B: Widely distributed on the staphylococcal chromosome C: On both the staphylococcal chromosome (TSST-1 and exfoliative toxins) and on plasmids (enterotoxins) D: On the staphylococcal chromosome in a pathogenicity island E: On plasmids