The Cell Cycle

Chromosomes

• Chromosomes are condensed strands of ____________.

• Many, many ____________ fit on one chromosome.

Chromosomes• The tips of the chromosomes are called

____________.• Chromosomes are bound in the middle

with ____________.• The long arm of

a chromosome is the _____ arm.

• The short arm of a chromosomes is the _____ arm.

Genes

• A ____________ is a section of a chromosome that codes for a specific ____________.

Hair Color

Eye Color

Height

Weight

Chromosomes• Each cell has

_____ of each kind of chromosome.

• They aren’t exactly alike, but they code for the same ____________.

• These are called ____________ ____________.

Blonde

Brown Eyes

Tall

Red Hair

Blue Eyes

Medium

Homologous Pair

Chromosomes• Usually

chromosomes are all jumbled up. This is called ____________.

• Only just before division do they condense down into ____________ chromosomes.

Chromosomes• Before a cell

____________, the ____________ must duplicate as well.

• The two halves of the duplicated chromosomes are called ____________ ____________. They are ____________ alike.

SIMILAR

IDENTICAL

Cell Division

Periods of the Cell Cycle

• G1 and G2 – ____________• S – ____________of DNA

• M – ____________(Cell Division)

_______________

Cell Division• ____________–

Growth and repair• ____________–

Creation of sex cells (____________)

• ____________ ____________ – Cell division in prokaryotes like bacteria

Mitosis• ____________ division • Duplicated chromosomes are

evenly distributed into two ____________ cells

• Purposes:– ____________ of single-

cell organisms (i.e. amoebas)

– ____________ repair– Cell ____________– ____________

____________ (i.e. bone lengthening)

Mitosis• All ____________ cells

(non-gametes) in an organism have the same number of ____________ and undergo mitosis.

• The chromosome number is characteristic of a given ____________ (e.g.humans 46, goldfish 94).

• ____________ cells have 2 sets of chromosomes – ____________.

Mitosis• Daughter cells are the ____________

____________ of the parent cell (they have the same number of ____________ )

• Parent cells are ____________, or ____ – this means they have 2 of each chromosome

• After mitosis daughter cells will be ____ as well (if a cell is ____________ or n, it did not go through mitosis – it went through ____________)

• If a cell grasshopper’s gland is 2n=24, it has _____ chromosomes– After mitosis the daughter cell will have

____ chromosomes.

I Pee on the MAT

• ____________• ____________(Mitosis)

• ____________(Mitosis)

• ____________(Mitosis)

• ____________(Mitosis)

Let's watch an animation!

Interphase• G1 Phase - First growth phase

– 2 pairs of ____________ begin forming

• S Phase - DNA is “____________” (chromosomes are ____________)– Each chromosome now consists

of 2 replicas called ____________ ____________ held together at the ____________

– ____________ needed for replication produced

Interphase

• G2 Phase - second growth phase

– Proteins made for division

– Completion of replication of ____________ pairs

• Cell ____________ and ____________ activities

– 90% of time

Interphase

Prophase• ____________ condenses to form

____________ ____________

• ____________ disappears

• Nuclear ____________ breaks down

Spindle Apparatus• Forms during ____________• Made of ____________• Spindle fibers pull

____________ where they need to go

• Centrioles/____________ at each pole (animals cells)– ____________: region of the cell that organizes

the spindle.• Some cancer medications interfere with the formation

of a cancer cell’s ____________. So, the ____________ can’t form and the cancer cell can’t go through mitosis.

Spindles are like Fishing Poles for

Chromosomes

Prophase

Prophase

Metaphase

• ____________ formation complete

• Chromatids line up at cell's ____________ ____________.

Metaphase

Anaphase• ____________ split• Sister ____________ separate into separate ____________ –

____________ as many chromosomes now!• Chromosomes are drawn to ____________/centrosomes

Anaphase

Telophase

• 2 new ____________

• Nuclear ____________ re-forms

• ____________ reappears

• ____________ disassembles

Telophase

Cytokinesis

• Division of ____________ into 2 daughter cells

• Animal cells: ____________ ____________ forms and pinches cell in two

• Plant cells: ____________ ____________ forms at equator of cell

Cell Plate in Plant Cell

Mitosis

Let's watch the whole process now.

Source: http://highered.mcgraw-hill.com/olc/dl/120073/bio14.swf

Chromosome Number Practice

Cell Type Ploidy # Chromosomes in Prophase

# Chromosomes in Anaphase

# Chromosomes in Daughter Cells

Fruit Fly 2n 8 16 8

Human Cheek

2n 46 92 46

Grasshopper Gland

2n 24 48 24

Onion Root 2n 6 12 6