Problem Analysis:
The worksheet provides six diagrams of cells in different phases of the cell cycle, and the task is to identify specific phases of mitosis based on the given images. The phases of mitosis are
prophase,
metaphase,
anaphase, and
telophase. Additionally, there is an interphase (before mitosis begins) and cytokinesis (after mitosis completes).
#### Key Phases of Mitosis:
1.
Prophase: Chromosomes condense, the nuclear envelope breaks down, and the mitotic spindle begins to form.
2.
Metaphase: Chromosomes align at the metaphase plate (equatorial plane) with their kinetochores attached to spindle fibers.
3.
Anaphase: Sister chromatids separate and are pulled toward opposite poles of the cell.
4.
Telophase: Chromosomes reach the poles, decondense, and a new nuclear envelope forms around each set of chromosomes.
Solution to Each Question:
####
1) Cells A and D show an early and a late stage of the same phase of mitosis. What phase is it?
-
Cell A: This cell shows chromosomes that are beginning to condense, and the nuclear envelope is still intact but starting to break down. This is characteristic of
prophase.
-
Cell D: This cell shows chromosomes that are fully condensed, and the nuclear envelope has completely broken down. The mitotic spindle is well-formed, and chromosomes are moving toward the metaphase plate. This is also part of
prophase but at a later stage.
Thus,
Cells A and D are in prophase.
####
2) Which cell is in metaphase?
-
Metaphase is characterized by chromosomes being aligned at the metaphase plate (equatorial plane) with their kinetochores attached to spindle fibers.
-
Cell C: This cell shows chromosomes neatly aligned at the center of the cell, which is the defining feature of metaphase.
Thus,
Cell C is in metaphase.
####
3) Which cell is in the first phase of mitosis?
- The first phase of mitosis is
prophase.
- As identified earlier,
Cell A shows the early stages of prophase, where chromosomes are beginning to condense and the nuclear envelope is breaking down.
Thus,
Cell A is in the first phase of mitosis (prophase).
Final Answers:
1.
Cells A and D show an early and a late stage of the same phase of mitosis. What phase is it?
-
Prophase
2.
Which cell is in metaphase?
-
Cell C
3.
Which cell is in the first phase of mitosis?
-
Cell A
Boxed Final Answers:
1. \(\boxed{\text{Prophase}}\)
2. \(\boxed{\text{Cell C}}\)
3. \(\boxed{\text{Cell A}}\)
Parent Tip: Review the logic above to help your child master the concept of phases of the cell cycle worksheet.
