In chickens, comb shape is determined by alleles at two loci (R, r and P, p). A walnut comb is produced when at least one dominant allele R is present at one locus and at least one dominant allele P is present at a second locus (genotype R_ P_). A rose comb is produced when at least one dominant allele is present at the first locus and two recessive alleles are present at the second locus (genotype R_pp). A pea comb is produced when two recessive alleles are present at the first locus and at least one dominant allele is present at the second (genotype rrP_). If two recessive alleles are present at the first and at the second locus (rrpp), a single comb is produced. Which of the following cross would produce ½ walnut and ½ pea comb ?

#Question id: 27374

#Unit 13. Methods in Biology

#Question id: 11610

#Unit 6. System Physiology – Plant

Environmental factors such as photoperiod and temperature can alter the levels of active gibberellins by affecting gene transcription for specific steps in the biosynthetic pathway such as;

a) Promotion of germination by light has been shown to be due to increases in GA1 levels resulting from a light-induced increase in the transcription of the gene for GA3ox, which converts GA20 to GA1

b) level of GA20-oxidase occurs in the highest amount in shoot tips and elongating stems, is increased under long-day conditions.  The fact that GA 20-oxidase is the enzyme that converts GA53 to GA20

c) Giving cold treatment  of Thlaspiarvense and a return to high temperatures, the ent-kaurenoic acid is converted to GA9, the most active gibberellin for stimulating the flowering response

d) Potato plants overexpressing the GA20ox gene showed tuberization, whereas transformation with the antisense gene for GA20ox inhibited tuberization

Which of the following from the given above statements is correct?

#Question id: 5773

#Unit 8. Inheritance Biology

Which of the following is not an effect of a mutation?

#Question id: 18221

#Unit 9. Diversity of Life Forms

#Question id: 15340

#Unit 4. Cell Communication and Cell Signaling