Chapter 2.3, Problem 26AQP

(a)

Summary Introduction

To draw:

A cell of the species containing one acrocentric pair of chromosomes and two metacentric pair of chromosomes in anaphase I.

Explanation of Solution

Pictorial representation:

Fig.1: Anaphase I

Anaphase I comes after metaphase I in meiosis. In anaphase I, homologous chromosomes are segregated from each other. Centromere is intact in this stage. Homologous chromosomes are pulled from each other with the help of spindle fibers.

(b)

Summary Introduction

To draw:

A cell of the species containing one acrocentric pair of chromosomes and two metacentric pair of chromosomes in metaphase I.

Explanation of Solution

Pictorial representation:

Fig.2: Metaphase I

Metaphase I comes after prophase I of meiosis. During this metaphase II, homologous chromosomes align themselves along the equatorial plate, also known as the metaphase plate. These homologous chromosomes are later separated in anaphase I.

(c)

Summary Introduction

To draw:

A cell of the species containing one acrocentric pair of chromosomes and two metacentric pair of chromosomes in anaphase II.

Explanation of Solution

Pictorial representation:

Fig.3: Anaphase II

Anaphase II comes after metaphase II in meiosis. During this anaphase II, spindle fibers pull the sister chromatids towards the poles and sister chromatids are segregated from

each other. It is similar to anaphase of mitosis.

(d)

Summary Introduction

To draw:

A cell of the species containing one acrocentric pair of chromosomes and two metacentric pair of chromosomes in metaphase II.

Explanation of Solution

Pictorial representation:

Fig.4: Metaphase II

Metaphase II comes after prophase II of meiosis. During this metaphase II, sister chromatids align themselves along the equatorial plate, also known as the metaphase plate. These sister chromatids are later separated in anaphase II.

Conclusion

Meiosis consists of two stages; meiosis I and meiosis II. Both these stages have anaphase and metaphase stages.