Page 68 - Biology - XII

Q7. What does a circle represent in pedigree chart?
Ans. Female

Q8. What is pedigree?
Ans. Pedigree is the study of a family for a particular trait/disease/defect, etc.

Q9. Give the reason why some traits are male traits.
Ans. Because the genes for the traits are Y-chromosome linked.
Q10. Which type of earlobes do you have?
Ans. Check your ear in a mirror.

Q11. A gene is present on Y-chromosome. Can it express the trait in females?
Ans. No, because Y-chromosome is not present in females.
Q12. The coding for ‘dimple’ in cheeks is present on which chromosome?
Ans. It is present on the autosome.

Q13. How do we represent male in the pedigree chart?
Ans. Male is represented by a square.
Q14. What does the horizontal line connecting a square and a circle indicate?
Ans. Marriage between the individuals.

Q15. Is there any signifi cance to study the pedigree?
Ans. Yes, it tells us/gives us the information regarding the movement of a trait.
Q16. Can we prevent certain hereditary diseases to occur?
Ans. Yes, careful study of the traits can prevent occurring in the off springs.

Q17. Does anyone have colour-blindness in your family?
Ans. _________ (Check and answer.)
Q18. How is a carrier trait represented in a pedigree chart?
Ans. By a dot in a symbol.
Q19. In a pedigree of earlobes, which type of earlobes trait is normal?
Ans. Free earlobes

Q20. Which type of earlobes are produced by a recessive gene in homozygous condition?
Ans. Fused earlobes

COMPETENCY BASED QUESTIONS

Multiple Choice Questions

Q1. Identify the symbol used in a pedigree for normal female.
(a) (b) (c) (d)

Q2. Which drawing in the pedigree will represent the siblings from the marriage?
(a) (b) (c) (d)

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