Genetics Practice Problems Quiz

A cross is made between two plants with white flowers. All the F1 progeny had red coloured flower. This is because… ( JUNE 2013)

4 different mutant lines showing similar phenotype where identified from a genetic screen. When genetic process among these mutants where carried out, the first mutant was found to complement the second, third and fourth mutant lines. However no other complementation groups do the 4 mutant lines belongs to?

When mutants having the same phenotype were crossed, the progeny obtained showed a wild-type phenotype. Thus the mutations are…

Cis-trans complementation test is carried out to identify… ( DEC 2013)

A recessive inherited disease is expressed only in individuals of blood group O and not expressed in blood group A, B or AB. Alleles controlling the disease and blood group are independently inherited. Normal woman with blood group A and her normal husband with blood group B already had a child with disease. The woman is pregnant for second time. What is the probability that second child will also have disease. ( JUNE 2017)

Mother of blood group ‘O’ has a blood group ‘A’ child. The father could be of blood type… (DEC 2011).

Blood group type ‘A’ antigen is a complex oligosaccharide which differs from ‘H’ antigen present in type ‘O’ individual by the presence of terminal… ( DEC 2012)

Mutation at two different loci of the same gene X results in altered functions. These two mutated versions of gene X are called … ( JUNE 2012).

Mendel crossed tall pea plants with dwarf once. The F1 plants where all tall. When these F1 plants were selfed to produce F2 generation, he got a 3:1 tall to draw ratio in the offspring. What is the probability that out of three plants of F2 generation picked up at random 2 would be dwarf and 1 would be tall ?

Assuming 1:1 sex ratio, what is the probability that three children from the same parents will consist of two daughters and one son ?

A plant of genotype AaBb is selfed. The two genes are linked and 50 map units apart. What proportion of progeny will have the genotype aabb? (DEC 2011)

How many genetically different gametes can be made by an individual of genotype AaBbccDDEe ? (JUNE 2011)

Genes A, B and C control three phenotypes which assort independently; A plant with genotype AaBbCc is selfed. What is the probability for progeny which show the dominant phenotype for at least one of the phenotypes controlled by genes A,B and C? ( JUNE 2015)

Of the following meiotic events

A) Formation of synaptonemal complex.

B) Crossing over

C) Arrangements of chromosomes at the equatorial plate at metaphase I.

D) Separation of chromatids at anaphase II.

Which one [s] lead to variation? (DEC 2013 GU)

Two siblings who inherit 50% of the genome from the mother and 50% from the father show lot of phenotypic differences. Which one of the following events during gametogenesis of the parents will maximally contribute to this difference ? ( DEC 2015)

In a heterozygous individual for a given gene, if a crossing over has occurred between the gene locus and centromere of the chromosome, the segregation of two alleles of the given gene will occur during meiosis at … ( DEC 2015)

In Drosophila melanogaster males, homologos chromosomes pair and segregate during meiosis but crossing over does not occur. At which stage of meiosis does segregation of two alleles often take place in these individuals ???

Upon studying a considerable number of different crosses in Drosophila, Morgan reaches the conclusion that all genes of this fly were clustered into 4 link groups corresponding to the four pairs of chromosomes. Further studies revealed that linkage is not absolute and it is broken frequently. It is broken in Prophase by a process called…

Two mutants of Drosophila melanogaster, one showing light red eye colour and the other showing dark brown eye colour, were crossed. In F1 all flies showed normal red eye colour. This indicated that the two locations are …

The ABO blood type in human is under control of autosomal multiple alleles. Colour blindness is recessive X-linked trade. A male with blood type ‘A’ and normal vision marries with a female who also has blood type ‘A’ and colour blind and has blood group ‘O’. The couple’s first child is male who is colour blind and has blood group ‘O’What is the probability that their next female child has normal vision and a blood group O.