Botany-Principles of Inheritance and Variation - Online Test

Q1. Sex determination in human being is
Answer : Option D
Explaination / 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.

Q2. XO type of sex determination is found in
Answer : Option C
Explaination / 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 A
Explaination / 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.

Q4. Female hetrogamety is present in
Answer : Option A
Explaination / 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.

Q5.

What does the chart given below represent?

Answer : Option D
Explaination / 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 B
Explaination / 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 D
Explaination / 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 B
Explaination / 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 B
Explaination / 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 B
Explaination / 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.