Answer : Option DExplaination / Solution:
In human beings, a pair of X chromosome is found in female and presence of an X and Y chromosome are determinant of male characteristic.
Answer : Option CExplaination / Solution:
In grasshopper, sex determination is of XO type, in which the males have only one X-chromosome besides the autosomes whereas females have a pair of X-chromosome.
Q3.Hemophilia is more commonly seen in human males than in human females because
Answer : Option AExplaination / Solution:
Hemophilia is sex-linked recessive disease due to mutation in X-chromosome. In this disease blood clotting do not takes place in case of injury and minor cut leads to death of individual.
Answer : Option AExplaination / Solution:
Female heterogamety is the formation of different types of gametes in female. Although male produce same types of gametes. In birds the female have ZW sex chromosome and male have ZZ sex chromosome.
Answer : Option DExplaination / Solution:
The chart given below represent XX-XO type of sex determination in which XX forms the female and XO develops as male. It is common in birds.
Q6.Two genes R and Y are located very close on the chromosomal linkage map of maize plant. When RRYY and rryy genotypes are hybridized, the F2 segregation will show:
Answer : Option BExplaination / Solution:
Two genes located very close on the chromosomal linkage map. Segregation of R and Y will not takes place due to linkage and passes to same gamete together but overall segregation can be expected as usual as dihybrid cross, 9:3:3:1.
Q7.Henking in 1891 observed a specific nuclear structure in 50% of sperms. He named this structure as
Answer : Option DExplaination / Solution:
The specific nuclear structure in few insects and 50 percent of the sperm observed by Henking was named as X body. Although its role in sex determination was not known to his time.
Q8.In human beings, if ovum fertilizes with a sperm carrying X-chromosome the zygote develops into
Answer : Option BExplaination / Solution:
Male produce two kinds of sperms, half carrying X and half carrying Y sex chromosome besides 22 autosomes. If ovum is fertilized by sperm carrying X chromosome the sex of child developed is female.
Q9.In our society women are blamed for producing female children as the growth and development of child occurs inside the mother womb. This statement is
Answer : Option BExplaination / Solution:
Women are not responsible for sex of child because they produce only one kind of gamete containing X-sex chromosome, on the other hand male produce two kinds of sperms half containing X and half Y sex chromosome.
Q10.Henking X-body present in 50% of sperms are now known as
Answer : Option BExplaination / Solution:
Henking trace a specific structure in 50% of sperms. He gave the name x-body to this structure but he was not able to explain the significance of this structure. Further, investigation revealed that x-body was a chromosome, called X-chromosome.
Total Question/Mark :
Scored Mark :
Mark for Correct Answer : 1
Mark for Wrong Answer : -0.5
Mark for Left Answer : 0