Chpt. 8 Bio Dynamite Review: Mitosis and the Cell Cycle

What are the 5 stages of mitosis?

1. Prophase
2. Prometaphase
3. Metaphase
4. Anaphase
5. Telophase

In Mitosis what occurs:

1. chromosome number is conserved
2. 2 daughter cells are made
3. Asexual reproduction

During Interphase what 2 things occur:

1. Growth
2.Chromosomes are copied in order to prepare for cell division

What is the M- phase?

-Includes Mitosis and cytokinesis
-Usually the shortest of the cell cycle
-All FIVE stages are here (Prophase, pro metaphase, metaphase, anaphase, telophase)

Interphase includes what 3 phases?

1. G1 "First Gap Phase"
2. S phase
3. G2 "Second Gap Phase"

Tip: During all 3 phases, cell growth is seen, we make organelles and proteins.

What occurs during the G1 phase?

cell begins to grow

What occurs during S phase?

Duplication of chromosomes

What occurs during the G2 phase?

cell prepares for division

In animal cells, where does the assembly of spindle microtubules begin?

centrosome

Flagella and cilia were made from microtubules in what arrangement?

9+2 arrangement

What does the centrosome consist of?

The centrosome consists of TWO Centrioles (Only in animal cells) that are perpendicular to each other

Plants do NOT have __________ but they do have a mitotic spindle.

Centrioles

How can you view chromosomes?

Karyotype

What are the Five things that occur during Stage One: Prophase?

1. Nucleoli disappear
2. Chromosomes condense
3.Centrioles move to opposite poles
4. Mitotic spindle begins its formation
5. Chromatin Fibers become tightly coiled; chromosomes are observable under a light microscope

What happens in Stage 2: Prometaphase?

1. Chromosomes become more condensed
2. Nuclear envelope fragments
3. Some of the microtubules attach to a kinetochore

What is a kinetochore?

A protein structure attached to the centromere that links the sister chromatids to the mitotic spindle

What occurs during Stage three: Metaphase?

1.Centrosomes are officially at opposite ends
2.Sister chromatids of each chromosome are attached to the spindle
3. Chromosomes are now lined up at the spindle equator

What occurs during Stage Four: Anaphase?

-Shortest stage of Mitosis
1. Cohesion proteins are cleaved, thus allowing sister chromosomes to separate from each other and move to opposite poles.
***AT the END of Anaphase, Cytokinesis BEGINS!

What occurs during Stage 5: Telophase?

1. 2 daughter Nuceli form, each with a diploid 2N number
2. Cytokinesis occurs but often begins a bit earlier
3. chromosomes decondense
4.NEW nuclear membrane forms

In animal cells, cytokinesis involves the formation of a :

Cleavage Furrow

What is the First sign of cleavage in animal cells?

the Cleavage Furrow

Cytokinesis in plants forms a what?

Cell plate
-The cell plate will partition off the daughter cells

How do Bacteria and Archaea (prokaryotes) reproduce?

Binary Fission
-The parent cell replicates its single chromosome, then divides it into two genetically IDENTICAL DAUGHTER CELLS----> Asexual reproduction

What is the most important checkpoint for the cell and what does it do?

G1: called the Restriction Point
-It responds to DNA damage; if the cell gets the "OK" from G1; then the cell cycle can continue
-IF it does NOT get the "OK" the cell switches to the NONDIVIDING state called G0

Most cells are _____ in our bodies.

G0 (non dividing)

In cancer (malignancy) we see___________

uncontrolled Mitosis
-abnormal changes occur within a cell and control point activity is lost

When a person with breast cancer eventually gets liver cancer what has occurred?

cancer cells can lose their cell attachment and often SPREAD (metastasize) to distant sites.
*Hence: Metastatic breast cancer

What do some chemotherapy drugs do that would stop cell division?

Disrupt the mitotic spindle

___________________ is a specific drug that destroys microtubules; thus stopping mitosis.

Colchicine

What are somatic cells?

all body cells except reproductive cells like eggs and sperm (haploid cells "N")

What are gametes?

eggs or sperm cells (sex cells)

What is a genome?

the genetic info in a cell

An array of microtubules that extends from each centrosome is called an ____________.

Aster

Describe the Spindle:

a structure made up of proteins and microtubules.
-The spindle includes:
1. centrosomes
2.asters
3.microtubules

What is a Zygote?

fertilized egg (2N)

When the eyes open of a baby or the webbing of fingers is lost; this programmed cell death is called?

Apoptosis

White blood cells die by____________________

apoptosis

What is a Neoplasm?

a new or abnormal growth

Cell size is limited by what 2 factors?

1. Nucleus capacity: must have enough DNA
2. Surface area to volume ratio

As a cell grows what occurs?

its Surface area to volume decreases

Lower surface area to volume ratio when a cell increases in size

When the surface area gets to low, the cell cannot meet its energy and metabolic requirements so what happens?

cell division