Chapter 10 - Cell Division and Mitosis

Slide 2 - 10.1 The Cycle of Cell Growth and Division: An Overview

Single-celled prokaryotic or eukaryotic organisms ______ and ________ as long as environmental conditions allow

grow

divide

Slide 2 - 10.1 The Cycle of Cell Growth and Division: An Overview

In multicellular eukaryotes, cell division is under strict control to __________

develop and maintain different subpopulations of cells

Slide 2 - 10.1 The Cycle of Cell Growth and Division: An Overview

Three parts of cell’s life cycle are

Cell growth and activity, including replication of DNA

Nuclear division (mitosis)

Division of the cytoplasm (cytokinesis)

Slide 3 - Two Types of Nuclear Division

_______ (Mitosis/Meiosis) is a growth process

Mitosis

Slide 3 - Two Types of Nuclear Division

Meiosis is a process of __________

sexual reproduction

Slide 3 - Two Types of Nuclear Division

A process divides the replicated DNA equally and precisely, generating daughter cells, which are exact genetic copies of the parent cell is ___________

Mitosis (a growth process)

Slide 3 - Two Types of Nuclear Division

produces daughter nuclei with half the number of chromosomes of the parental nucleus

Meiosis (a process of sexual reproduction)

Slide 3 - Two Types of Nuclear Division

In Meiosis, the arrangements of genes on chromosomes are different from those in the _______

parent cell

Slide 4 - The Products of Mitosis

Mitosis partitions replicated DNA ___________ and _____________

equally

precisely

Slide 4 - The Products of Mitosis

___________ is a master program of molecular checks and balances

Mitosis

Slide 4 - The Products of Mitosis

DNA synthesis replicates each DNA chromosome into _____ copies with ____________

two

almost perfect fidelity

Slide 4 - The Products of Mitosis

_________ separates replicated DNA molecules precisely into the daughter cells

Mitotic cytoskeleton

Slide 4 - The Products of Mitosis

What are chromosomes?

The nuclear units of genetic information divided and distributed by mitotic cell division

Slide 5 - Chromosomes

In eukaryotes, the hereditary information within the nucleus is distributed among ________

individual, linear DNA molecules

Slide 5 - Chromosomes

In eukaryotes, the hereditary information within the nucleus is ______

distributed among individual, linear DNA molecules

Slide 5 - Chromosomes

DNA molecules combine with ________ that stabilize the DNA molecules, assist in ___________ during cell division, and influence the expression of __________

proteins

packaging DNA

individual genes

Slide 5 - Chromosomes

In a cell, each chromosome is composed of __________ and ___________

In a cell, each chromosome is composed of one DNA molecule and its associated proteins

Slide 6 - Packing DNA (1 of 2)

DNA fits into a nucleus because it is packed into a shorter length by __________ proteins

histone

Slide 6 - Packing DNA (1 of 2)

Other _______ proteins also associate with DNA; the complex of DNA and all its associated proteins is _______

nonhistone

chromatin

Slide 6 - Packing DNA (1 of 2)

In a __________, an eight-protein _______ forms when DNA winds around the histones H2A, H2B, H3, and H4

nucleosome

nucleosome core particle

Slide 6 - Packing DNA (1 of 2)

What segment of DNA connects nucleosomes?

A short linker segment

Slide 7 - Packing DNA (2 of 2)

Nucleosomes and linkers appear as _________ on a string under electron microscopes

beads

Slide 7 - Packing DNA (2 of 2)

The ______________ is named from the diameter of the beads and compacts DNA by a factor of about ——

10-nm chromatin fiber

7

Slide 7 - Packing DNA (2 of 2)

Further packing occurs in the __________ when the nucleosome and linker are bound by the _________ protein H1

30-nm chromatin fiber

fifth histone

Slide 7 - Packing DNA (2 of 2)

The ________ model predicts the nucleosomes spiral helically with about _____nucleosomes per turn

solenoid

six

Slide 7 - Packing DNA (2 of 2)

Chromatin packing continues at higher levels, with _______ being loosely packed and ___________ showing dense packing

euchromatin

heterochromatin

Slide 8 - DNA Functions as an InformationContaining Molecule (1 of 2)

Watson and Crick’s model revealed ________ as the biological reservoir of information

DNA

Slide 8 - DNA Functions as an InformationContaining Molecule (1 of 2)

As per Watson and Crick’s model __________ stores information required for an organism’s ___________

DNA

growth and reproduction

Slide 8 - DNA Functions as an InformationContaining Molecule (1 of 2)

Information consists of sequences of _________ in nucleic acid

nucleotides

Slide 8 - DNA Functions as an InformationContaining Molecule (1 of 2)

Four __________ function like letters in an alphabet

_________ has meaning, like the order of letters in a word

nitrogenous bases

Sequence of bases

Slide 9 - The Solenoid Model

Slide 10 - Cellular Mechanism

Slide 11 - Sister Chromatids

How and when are sister chromatids produced?

Before a cell divides in mitosis, duplication of each chromosome (and its proteins) produces two identical copies called sister chromatids

Slide 11 - Sister Chromatids

Sister chromatids are held together by ________

sister chromatid cohesion

Slide 11 - Sister Chromatids

What separates the sister chromatids?

mitosis separates them, placing one in each of two daughter nuclei

Slide 11 - Sister Chromatids

_________ hold the sister chromatids together until they are removed

Cohesins (protein)

Slide 11 - Sister Chromatids

The equal distribution of chromosomes into each of two daughter nuclei is called __________

chromosome segregation

Slide 11 - Production of Sister Chromatids

Slide 12 - Ploidy

What is Ploidy?

The number of chromosome sets in a cell or species is called its ploidy

Slide 12 - Ploidy

microorganisms that have only one copy of each type of chromosome in their nuclei are __________ or ______

haploid

n

Slide 12 - Ploidy

Explain Polyploid

Many plant species, have three, four, or even more complete sets of chromosomes in each cell – They are polyploid

Slide 12 - Ploidy

What are diploid?

Most eukaryotes have two copies of each type of chromosome in their nuclei – they are diploid, or 2n

Slide 12 - Ploidy

The two chromosomes of each pair in a diploid cell are called ____________ – one is from the mother, the other from the father

homologous chromosomes

Slide 12 - Ploidy

Homologous chromosomes have the ______ genes in the _______ order in the DNA of the chromosomes

same

same

Slide 13 - What Is a Chromosome? (1 of 3)

What is a chromosome?

Single long double helix of DNA wrapped around proteins called histones

Slide 13 - What Is a Chromosome? (1 of 3)

DNA encodes cell’s __________

genetic information

Slide 13 - What Is a Chromosome? (1 of 3)

Gene”

___________ in chromosome

________ for specific RNA

Region of DNA

Codes

Slide 14 - What Is a Chromosome? (2 of 3)

Chromosomes _________ into compact structures

condense

Slide 14 - What Is a Chromosome? (2 of 3)

________ is distributed to each of the _____ cells

One copy of each chromosome

two daughter

Slide 14 - What Is a Chromosome? (2 of 3)

What is a chromatid?

Each double-stranded DNA copy is called a chromatid

Slide 14 - What Is a Chromosome? (2 of 3)

Chromatids are attached along their entire length by proteins called ________

cohesins

Slide 14 - What Is a Chromosome? (2 of 3)

Once mitosis begins, they are attached only at __________

centromere

Slide 14 - What Is a Chromosome? (2 of 3)

Before mitosis, each chromosome is replicated. What are the steps involved in ?

• Chromosomes condense into compact structures

• One copy of each chromosome is distributed to each of the two daughter cells

• Each double-stranded DNA copy (chromatid) are attached along their entire length by proteins called cohesions

• Once mitosis begins, they are attached only at centromere

Slide 15 - What Is a Chromosome? (3 of 3)

Chromatid copies that remain attached at centromere are _______

sister chromatids

Slide 15 - What Is a Chromosome? (3 of 3)

Two attached sister chromatids are still considered a __________

single chromosome

Slide 16 - Structures Involved in Mitosis

A structure containing genetic information in the form of genes

Chromosome

Slide 16 - Structures Involved in Mitosis

The material that makes up eukaryotic chromosomes; consists of a DNA molecule complexed with histone proteins

Chromatin

Slide 16 - Structures Involved in Mitosis

The two attached, double-stranded DNA copies of a replicated chromosome.

Sister chromatids

Slide 16 - Structures Involved in Mitosis

When chromosomes are replicated, they consist of two genetically identical _________

sister chromatids

Slide 16 - Structures Involved in Mitosis

When sister chromatids separate during mitosis, they become _________

independent chromosomes

Slide 16 - Structures Involved in Mitosis

Specialized regions of chromosomes where sister chromatids are most closely joined to each other

Centromeres

Slide 16 - Structures Involved in Mitosis

The structures on sister chromatids where microtubules attach

Kinetochores

Slide 16 - Structures Involved in Mitosis

What is the microtubule-organizing center in animals and certain plants and fungi.

centrosome. Each pole in the spindle apparatus is a centrosome

Slide 16 - Structures Involved in Mitosis

What is the cytoskeletal filaments that form the spindle apparatus, which consists of polar microtubules, kinetochore microtubules, and astral microtubules

Microtubules

Slide 16 - Structures Involved in Mitosis

The dynein and kinesin motors that participate in moving chromosomes and the poles of the spindle apparatus

Microtubule motor proteins

Slide 17 - 12.1 Changes in Chromosome Morphology

What is it that consists of a single long DNA double helix wrapped around proteins (which are too small to distinguish at this scale)

Unreplicated chromosome

Slide 17 - 12.1 Changes in Chromosome Morphology

What is it that consists of 2 copies of the same DNA double helix

Replicated Chromosome

Slide 17 - 12.1 Changes in Chromosome Morphology

What is it that consists of DNA condensed around its associated proteins resulting in a compact chromosome that is 10,000 times shorter than its original length.

Condensed replicated chromosome

Slide 17 - 12.1 Changes in Chromosome Morphology

Diagram

Slide 18 - Research Method: Preparing a Human Karyotype

List the protocols to prepare a human karyotype

1. Add sample to culture medium that has stimulator for growth and division of cells (white blood cells in the case of blood). Incubate at 37oC.

2. Stain the cells so that the chromosomes are distinguished.

3. View the stained cells under a microscope equipped with a digital imaging system and take a digital photograph

Slide 18 - Research Method: Preparing a Human Karyotype

Interpreting the Results: The karyotype is evaluated with respect to the _________

scientific question being asked.

Slide 19 - 10.2 The Mitotic Cell Cycle

What are the three main events in a cell cycle:

interphase,

mitosis (M phase),

and cytokinesis

Slide 19 - 10.2 The Mitotic Cell Cycle

What are the phases of Interphase?

• G1 phase, in which the cell grows

• S phase, in which DNA replicates and chromosomal proteins are duplicated

• G2 phase, in which cell growth continues and the cell prepares for mitosis

Slide 19 - 10.2 The Mitotic Cell Cycle

In which phase of the Interphase does the DNA replicates and chromosomal proteins are duplicated?

S Phase

Slide 19 - 10.2 The Mitotic Cell Cycle

In which phase of the interphase does the cell prepares for mitosis and in that phase what happens to the cell growth?

G2 Phase and the cell growth continues in that phase

Slide 19 - 10.2 The Mitotic Cell Cycle

Diagram

Slide 21 - Figure 12.4 An Overview of the Cell Cycle

Diagram

Slide 22 - How the chromosome no. and ploidy changes during the mitotic cell cycle - Diagram

Slide 23 - M Phase: Mitosis and Cytokinesis: A

What are phases and explain them?

1. Interphase

   1. After chromosome replication, each chromosome is composed of 2 sister chromatids. Centrosomes have replicated

2. Prophase

   1. Chromosomes condense and spindle apparatus begins to form

3. Prometaphase

   1. Nuclear envelope breaks down. Microtubles contact chromosomes at kinetochores

4. Metaphase

   1. Chromosomes complete migration to middle of cell

Slide 23 - M Phase: Mitosis and Cytokinesis: A - Diagram

Slide 24 - M Phase: Mitosis and Cytokinesis: B - Diagram

What are the phases?

5. Anaphase

   1. Sister chromatids separate into daughter chromosomes which are pulled to opposite poles of spindle apparatus

6. Telophase

   1. Nuclear envelope re-forms and chromosomes de-condense

7. Cell division begins:

   1. Actin-myosin ring case plasma membrane to begin pinching in

8. Cell division is complete:

   1. Two daughter cells form

Slide 24 - M Phase: Mitosis and Cytokinesis: B - Diagram

Slide 25 - Interphase

Usually, ________ is the only phase of the cell cycle that varies in length – other phases are typically uniform in length

G1

Slide 25 - Interphase

G1 is also the stage in which many cell types __________ and are ______________ into a G0 phase

stop dividing

shunted

some cells in G0 reenter G1, others never resume the cell cycle

Slide 25 - Interphase

___________ trigger each phase of the cell cycle and regulate the ____________ that a cell goes through

Internal regulatory controls

overall number of cycles

Slide 26 - The Stages of Mitosis: Interphase - Diagram

Slide 27 - Mitosis proceeds in Five Stages

Following interphase, mitosis can be divided into five sequential stages:

• Prophase

• Prometaphase

• Metaphase

• Anaphase

• Telophase

Slide 27 - Mitosis proceeds in Five Stages

Which phase of mitosis does Cytoplasmic division (cytokinesis coincides with?

telophase

Slide 30 - Prophase

Explain the different stuff that happens in Prophase

• Chromosomes condense into chromatin

• Nucleolus becomes smaller and disappears

• The mitotic spindle begins to form between the two centrosomes as they migrate toward the opposite ends of the cell, where they will form spindle poles

Slide 31 - Prophase

Spindle apparatus consists of ___________

microtubules

Slide 31 - Prophase

Spindle apparatus forms from ________

microtubule-organizing center

Slide 31 - Prophase

MTOCs define [#] poles of spindle apparatus

_____ ends of microtubules grow out from each pole

two

positive

Slide 31 - Prophase

_______ extend from each spindle pole and overlap with each other

Polar microtubules

Slide 31 - Prophase

Structure that contain centrioles?

Centrosome

Slide 31 - Prophase

Centrosome replicates during _________ Phase

S Phase

Slide 32 - Centrosome (centriole) vs, Centromere

Slide 33 - Prometaphase

Prometaphase - Begins when the ________

nuclear envelope breaks down

Slide 33 - Prometaphase

in Prometaphase - __________ grow from centrosomes at opposite spindle poles toward the center of the cell

Spindle microtubules

Slide 33 - Prometaphase

Prometaphase: A __________forms on each sister chromatid at the __________(the point where chromatids are joined in sister chromatid adhesion)

kinetochore

centromere

Slide 33 - Prometaphase

Kinetochore microtubules attach to the ___________

• Chromosomes are pushed and pulled by ____________ until they reach ________

kinetochores

microtubules

the middle of spindle