Biology : Principles of Inheritance and Variation

In human the inheritance of sex linkage takes place through :

• autosomes

• Y - chromosome

• X- chromosome

• both 'b' and 'c'

Frameshift mutation occurs when

• base is subsituted

• base is deleted or added

• anticodons are absent

• none of these

Pure line breed refers to

• heterozygosity only

• heterozygosity and linkage

• homozygosity only

• homozygosity and self assortment

If a homozygous red flowered plant is crossed with a homozygous white flowered plant, the offspring would be

• half red-flowered

• all red-flowered

• half white-flowered

• half pink-flowered.

The ratio in a dihybrid test cross between two individuals is given by

• 2 : 1

• 1 : 2 : 1

• 3 : 1

• 1 : 1 : 1 :1

If an inheritable mutation is observed in a population at high frequency, it is referred as

• DNA polymorphism

• Expressed sequence tag

• Sequence annotation

• Linkage

• Linkage

Multiple allelism is observed in

• flower colour in Snapdragon

• pod colour in Pisum sativum

• haemophilia in man

• sex determination in birds

• sex determination in birds

The graphical representation to calculate the probability of all possible genotypes of offsprings in a genetic cross was developed by

• Gregor Mendel

• Kornberg

• Har Gobind Khorana

• George Gamow

• George Gamow

Choose the wrong statement

• Failure of segregation of chromatids during cell division results in aneuploidy

• Additional copy of 'X' chromosome in males results in Klinefelter's syndrome

• Closely located genes in a chromosome always assert independently resulting in recombinants

• According to Mendel, recessive character never blend in heterozygous condition

• According to Mendel, recessive character never blend in heterozygous condition

Choose the wrong statement

• In grasshopper, besides autosomes males have only one X-chromosome, whereas females have a pair of X-chromosomes.

• In XY type of sex determination, both males and females have same number of chromosomes.

• In Drosophila, males have one X and one Y chromosome, whereas females have a pair of Xchromosome besides autosomes

• In birds, females have one Z and one W chromosomes, whereas males have a pair of Z chromosomes besides autosomes

• In birds, females have one Z and one W chromosomes, whereas males have a pair of Z chromosomes besides autosomes