Principles of Inheritance and Variation

A test cross is carried out to:

In Mendel's experiment, when tall and short plants were crossed, the F1 plants were all tall. When these F1 tall plants were selfed, the phenotypic ratio of F2 was:

Which of the following will not result in variations among siblings?

A disease caused by an autosomal primary nondisjunction is:

In a dihybrid cross, if you get 9:3:3:1 ratio it denotes that:

The chromosomal disorder caused by the presence of an additional copy of chromosome 21 is:

In ABO blood grouping, if both antigens are present, the blood group is:

Multiple alleles are found when:

Match List I with List II — A. Incomplete dominance, B. Co-dominance, C. Pleiotropy, D. Polygenic inheritance — with I. Human skin colour, II. Inheritance of flower colour in Antirrhinum sp., III. Phenylketonuria disease in humans, IV. ABO blood groups ( NEET 2026)

Which of the following statements are true with reference to the sex-determination in honeybees? A. An offspring formed from the union of a sperm and an egg, develops as a female (queen or worker). B. An unfertilized egg develops as a male by parthenogenesis. C. A male has half the number of chromosomes than that of a female. D. Males produce sperms by meiosis. E. Honeybees have a haplodiploid sex-determination system. ( NEET 2026)

Which one of the following disorders is caused by the substitution of Glutamic acid (Glu) by Valine (Val) at the sixth position of the beta globin chain of the haemoglobin molecule? ( NEET 2026)

What is the probability of having children with O blood group, where both mother and father are heterozygous for A and B blood group, respectively? ( NEET 2026)

In a population of a grasshopper species, the chromosome number of some members is 23 and some other members possess 24 chromosomes. The 23 and 24 chromosome-bearing members in this species are ( NEET 2026)

In which animal do haploid cells divide mitotically to produce gametes? ( NEET 2026)