CaylorBiology 101 Unit 5

Day 4 notes

Before class starts…

• Make sure you have turned in your DNA fingerprinting assignments

• Put up electronics, food and drinks

Getting Started…

• If you were the prosecutor in this criminal case, who would you want arrested? Why?

• How is this different than the DNA sample you looked at yesterday?

The plan….

Thurs: Mitosis/Meiosis and Internet Activity

Fri: Reebops Lab Meiosis

Mon: Mutations/Review for Midterm

Tues: Midterm Exam

What is the cell cycle?

• Sequence of growth and division in the cell

1. Interphase is the growth period where replication occurs

2. Mitosis

What is mitosis?

• division of cells producing two cells with the same number of chromosomes

• Ex: 46 chromosomes in human body cells, so ALL body cells should have 46

What is involved in Prophase?• Chromatin (normal

form of DNA) coils into chromosomes

• The nucleus disappears

• Centrioles form and move to opposite poles of cell

• Spindle fibers form from centrioles and begins to cross cell

What is involved in Metaphase?

• Chromosomes line up in the middle of the cell

• Spindle forms across the cell from centrioles

What is involved in Anaphase?

• Spindle fibers begin to shorten

• Chromosomes pulled apart

• Move to opposite poles

What is involved in Telophase?

• Chromosomes unwind into chromatin

• Spindle fibers break down

• Nucleolus and nuclei reform

• Plasma membrane begins to pinch in

What is Cytokinesis?• Division of cytoplasm• In animal cells: cell membrane

continues to pinch in until two cells are formed

• In plant cells: cell plate forms in center of cell and eventually splits cells

• At the end of mitosis, two new cells are produced; called “daughter” cells

Today’s Assignments:

Choose between the following:

Mitosis lab- in lab area; paper on table 2

Mitosis internet activity- paper on computer cart

EVERYONE: Mitosis/Cancer connection reading questions- on front table

Quick Quiz 11. Which part of the cell cycle involves the copying of the

DNA? a. interphase b. mitosis

2. What is the division of the cytoplasm called? a. cytolysis b. cytofission c. cytokinesis

A. Prophase B. Metaphase C. Anaphase D. Telophase

3. Which phase involves the splitting of the chromosomes?4. Which phase involves the chromosomes lining up in the

center of the cell?5. Which phase involves the formation of chromosomes?