Chapter 3.3, Problem 37AQP

a.

Summary Introduction

To draw:

The chromosomes as they would appear in each type of gamete produced by the cross $\text{AaBb}\times \text{aabb}$.

Introduction:

During ${\text{G}}_{\text{1}}$ stage, the chromosomes do not undergo replication and thus are found in a single set. The cell enters S phase after the completion of ${\text{G}}_{\text{1}}$ stage in which the replication of DNA starts. When a cell enters ${\text{G}}_{\text{2}}$ stage, it receives two sets of chromosome due to chromosome duplication in S phase. When a cell enters metaphase the number of chromosomes remains same. In metaphase of mitosis, the chromosomes are held together by a centromere.

b.

Summary Introduction

To draw:

The chromosomes as they would appear in a cell at ${\text{G}}_{\text{1}}$ , ${\text{G}}_{\text{2}}$ and metaphase of mitosis for each type of progeny resulting from $\text{AaBb}\times \text{aabb}$ cross.

Introduction:

During ${\text{G}}_{\text{1}}$ stage, the chromosomes do not undergo replication and thus are found in a single set. The cell enters S phase after the completion of ${\text{G}}_{\text{1}}$ stage in which the replication of DNA starts. When a cell enters ${\text{G}}_{\text{2}}$ stage, it receives two sets of chromosome due to chromosome duplication in S phase. When a cell enters metaphase the number of chromosomes remains same. In metaphase of mitosis, the chromosomes are held together by a centromere.