NEET · Biology · Principles of Inheritance and Variation doubts
10 doubts found
A colour-blind man marries a woman with no colour blindness in her family. Why are their sons normal but their daughters carriers?
Colour blindness is X-linked recessive.
Two pink four-o'clock flowers are crossed and give red, pink and white in a 1:2:1 ratio, not 3:1. Why?
Flower colour here shows incomplete dominance, so the heterozygote (Rr) is pink -- a visible blend, not red.
A woman of blood group AB marries a man of group O. What groups can the children be, and why never AB or O?
The AB mother contributes either I-A or I-B; the O father (ii) contributes only i.
What does “Law of dominance” actually mean in Principles of Inheritance and Variation, and why does it matter for NEET?
in a heterozygote only the dominant allele is expressed while the recessive one stays masked.
I keep getting “Law of dominance” questions wrong in Principles of Inheritance and Variation. What's the trap?
thinking the recessive allele is lost or destroyed in the F1.
What does “Law of segregation” actually mean in Principles of Inheritance and Variation, and why does it matter for NEET?
the two alleles of a gene separate during gamete formation, so each gamete carries only one of them.
I keep getting “Law of segregation” questions wrong in Principles of Inheritance and Variation. What's the trap?
thinking both alleles of a gene can enter the same gamete.
What does “Independent assortment” actually mean in Principles of Inheritance and Variation, and why does it matter for NEET?
alleles of different genes assort independently into gametes, giving the 9:3:3:1 dihybrid ratio.
I keep getting “Independent assortment” questions wrong in Principles of Inheritance and Variation. What's the trap?
applying independent assortment to genes that are linked on the same chromosome.
What does “Sex determination (XX-XY)” actually mean in Principles of Inheritance and Variation, and why does it matter for NEET?
human females are XX and males XY, so the father's sperm (X or Y) decides the child's sex.