Download presentation
Presentation is loading. Please wait.
1
Mitosis: When Cells Divide
2
Introduction to Mitosis
Define the following: 1. Chromosome: 9. Draw the phases of 2. Chromatid: mitosis (p.247) 3. Centromere: 4. Prophase: 5. Metaphase: 6. Anaphase: 7. Telophase 8. Diploid number
3
Mitosis Mitosis: the division of a cell’s nucleus that leads to the formation of two identical cells
4
Chromatin to Chromosomes
Chromatin: long, threadlike strands of DNA (genetic material) Chromosome: condensed DNA that is formed during mitosis DNA wraps around proteins to form chromosome Genes that control traits are located on these chromosomes
5
The Human Genome (Karyotype)
6
Chromosomes Before mitosis, DNA replicates
Chromosomes are then composed of two similar halves, called chromatids When two chromatids are together they are called sister chromatids (aka homologous chromosomes) Attached at the centromere Chromatids Centromere
7
Chromosomes Sister Chromatids each come from a parent (Mom or Dad)
They are the same (homologous) Sister Chromatids Centromere One chromatid (dark blue) Parent A One chromatid (light blue) Parent B
8
Chromosomes – Questions
Human genetic material is organized into _______________. Label A and B. Half of each chromosome comes from ______ and half from ______.
9
Where Does Mitosis Occur?
Somatic (body) cell: any cell of the body that is not sperm or egg Mitosis occurs here Body cells are diploid: having two sets of each chromosome Diploid number in humans is 46 Mitosis creates EXACT copies of itself Original cell DIPLOID creates two identical cells both DIPLOID
10
Where Does Mitosis NOT Occur?
Gametes (sex cells): egg, sperm, pollen ovule of flower, spores Gametes are haploid: having only one set (half) of each chromosome Haploid number is humans is 23
11
Haploid or Diploid? Haploid or Diploid? How many sets of chromosomes?
12
Cell Types and Division – Questions
Division of the nucleus of body cells is ________. There are two types of cells in the human bodies: body cells and _________. Cells that undergo cell division are ______________ to each other.
13
Interphase The cells prepares to divide in INTERPHASE
Interphase occurs BEFORE mitosis G1: cell growth S: DNA replicates G2: duplication of organelles, prepare for mitosis
14
Mitosis Prophase- Metaphase- DNA condenses into chromosomes
Nuclear envelope disappears Metaphase- Chromosomes line up in the middle
15
Mitosis Anaphase- Telophase- Cytokinesis- sister chromosomes separate
nuclei divide, nuclear envelope reforms Cytokinesis- cells separate
16
How to remember the phases of mitosis
In order – PMAT Prophase Metaphase Anaphase Telophase
18
Interphase Cells in normal living processes
Cell Grows and replicates DNA and organelles Replicates centrioles
19
Prophase Chromatin condenses into chromosomes Centrioles separate
Spindle apparatus begins to form Nuclear envelope disappears
20
Metaphase Chromosomes line up (at the metaphase plate)
Spindle fiber connects to chromosome at centromere Centrosome Centromere Metaphase plate Sister chromatids Polar microtubules
21
Sister chromatids separate
Anaphase Sister chromatids separate Individual chromatids are moved apart
22
Telophase and Cytokinesis
chromosomes gather at opposite ends of the cell Chromosomes lose shape New nuclear envelope forms Cytokinesis: Cytoplasm pinches into 2 daughter cells Each daughter cell has identical duplicate chromosomes
24
Discussion Questions What are the four phases of the cell cycle?
How are cytokinesis, and telophase different? What is important about metaphase? Where are genes found? What is the difference between a chromatid and a homologous chromosome? Cancer cells undergoing mitosis in 6 hours Mitosis 1 3D Mitosis 2
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.