Inheritance

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54

Question 31

In mammals, males have two different sex chromosomes ( $X\,$ and $Y$ ) and females have two similar sex chromosomes ( $X\,$ and $X$ ).

However, in many reptiles (such as certain species of lizards), females have two different sex chromosomes ( $Z\,$ and $W$ ), while males have two similar sex chromosomes ( $Z\,$ and $Z$ ).

Complete the genetic diagram to show how sex is inherited in these reptiles.

Genotype of male parent: $‾\underline{\qquad\qquad}$
Genotype of female parent: $‾\underline{\qquad\qquad}$
Gametes from male parent: $‾\underline{\qquad\qquad}$
Gametes from female parent: $‾\underline{\qquad\qquad}$
Genotypes of offspring: $‾\underline{\qquad\qquad}$
Sex of offspring: $‾\underline{\qquad\qquad}$

[3]

Reptile eggs contain nutrients that the growing embryo needs to develop outside the mother's body.

Suggest one food molecule (major nutrient) present in the yolk of a reptile egg and describe the role of this molecule in the growth and development of the embryo.

[2]

Suggest one advantage of the egg being enclosed in a leathery, protective shell.

[1]

Egg yolks are also a source of Vitamin D. Give another source of Vitamin D in the human diet (or lifestyle) and describe the function of Vitamin D in humans.

[2]

The number of chromosomes in the gametes (sperm and egg) of reptiles is less than the number of chromosomes in their body cells. Explain how the correct number of chromosomes is maintained in the offspring across generations.

[3]

Inheritance

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54

Question 31

In mammals, males have two different sex chromosomes ( $X\,$ and $Y$ ) and females have two similar sex chromosomes ( $X\,$ and $X$ ).

However, in many reptiles (such as certain species of lizards), females have two different sex chromosomes ( $Z\,$ and $W$ ), while males have two similar sex chromosomes ( $Z\,$ and $Z$ ).

Complete the genetic diagram to show how sex is inherited in these reptiles.

Genotype of male parent: $‾\underline{\qquad\qquad}$
Genotype of female parent: $‾\underline{\qquad\qquad}$
Gametes from male parent: $‾\underline{\qquad\qquad}$
Gametes from female parent: $‾\underline{\qquad\qquad}$
Genotypes of offspring: $‾\underline{\qquad\qquad}$
Sex of offspring: $‾\underline{\qquad\qquad}$

[3]

Reptile eggs contain nutrients that the growing embryo needs to develop outside the mother's body.

Suggest one food molecule (major nutrient) present in the yolk of a reptile egg and describe the role of this molecule in the growth and development of the embryo.

[2]

Suggest one advantage of the egg being enclosed in a leathery, protective shell.

[1]

Egg yolks are also a source of Vitamin D. Give another source of Vitamin D in the human diet (or lifestyle) and describe the function of Vitamin D in humans.

[2]

[3]

Inheritance

Question 31

Inheritance Questions

Inheritance

Question 31

Inheritance Questions