When Morgan hybridised yellow-bodied, white-eyed females to brown-bodied, red-eyed males and intercrossed their F1 progeny, the F2 ratio deviated very significantly from the 9:3:3:1 ratio. this can be attributed to the fact that:
(1) The genes are located on X and Y chromosomes
(2) Fruit fly has abnormal chromosomes
(3) The genes are located on the X chromosome
(4) the genes exhibit incomplete dominance
When the two genes in a dihybrid cross are situated on the same chromosome:
(1) The proportion of parental gene combinations was much higher than the non-parental type
(2) The proportion of parental gene combinations was much lesser than the non-parental type.
(3) The propagation of parental gene combinations was equal to the non-parental type
(4) Only recombinants are formed
A couple has a daughter. What is the probaility that their next child will be a daughter?
(1) 0 %
(2) 25 %
(3) 50 %
(4) 100 %
It is unfortunate that in our society women are blamed for producing female children and have been obstracised and ill-trated because:
(1) The sex is determined by the type of sperm fertilizing the egg.
(2) The sex is determined by the type of egg fertilizing the sperm.
(3) the sex is determined by the hormones produced by the fetus
(4) the sex is determined by the God's Will
A test cross is done to find out
(1) Fitness of an organism
(2) Genotype of a plant expressing dominant phenotype
(3) The suitable parents for a Mendelian Cross
(4) The hidden genotypic ratio of F2 phenotypes
Identify the incorrect statement:
(1) In addition to recombination, mutation is another phenomeonon that leads to variation in DNA.
(2) Chromosomal aberrations are commonly observed in cancer cells.
(3) A classical example of a point mutation is sickle cell anaemia.
(4) Non ionising radiations cannot be mutations.
Pedigree analysis is resorted to for genetic analysis in humans rather than conventional genetic methods because:
I. Choice matings are not possible
II. Number of progeny is limited
Of the two statements:
(1) Only I is correct
(2) Only II is correct
(3) Both I and II are correct
(4) Both I and II are incorrect
In a monohybrid cross F1 progeny resemble neither of the parents. What would be true in this case?
1. The parental traits would not appear in any of the F2 -progenies
2. The F2 phenotypic ratio will be different from the F2 genotypic ratio
3. It could be a case of incomplete donminance
4. The F2 genotypic ratio will be similar to any Mendelian monohybrid cross
The two alleles of a gene pair are located on:
1. Homologous sites on homologous chromosomes
2. Heterologous sites on homologous chromosomes
3. Homologous sites on heterologous chromosomes
4. Heterologous sites on heretologous chromosomes
Male heterogamety is not seen in:
(2) Melandrium album
(4) Fruit fly