CELL CYCLE

Small

size cells need to be

volume (inside of the cell)

when a cell grows, what grows faster?

divide

what a cell will do instead of growing larger...

larger cells place a greater demand on its DNA and organelles & more difficult for nutrients and wastes to enter and exit the membrane

why don't cells get large?

interphase, mitosis, and cytokinesis

3 main stages of a cell's life (in order)

interphase

cells spend most of their time in...

Mitosis

shortest cell cycle stage

Interphase

longest cell cycle stage

cells grow

what happens in G1?

the cells DNA is replicated

what happens in S?

cells prepare for mitosis by making organelles and molecules needed

what happens in G2?

Prophase, Metaphase, Anaphase, Telophase

steps of mitosis(PMAT)

centrioles

what organelle is needed for cell division?

the relaxed form of DNA used to make chromosomes

What is Chromatin?

Chromatin is coiled up into chromosomes

How does Chromatin become Chromosomes?

centromere

The center of a chromasome

sister chromatids

the "legs" of a chromosome

replace damaged cells like when humans get cut and asexual reproduction

Mitosis benefits...

Binary Fission

bacteria and other organisms reproduce asexually through mitosis its called...

G1, S, G2, P, M, A, T, Cytokinesis

cell cycle stages in order(all the substages for the main ones)

cells grow, DNA replication, cell prepares for mitosis, cell division

G1, S, G2, and M in order (by what occurs in the stage)

Interphase

G1, S, and G2 are apart of what stage...

Mitosis

PMAT is apart of what phase

Centrioles

Chromosome

Centromere

Nuclear Envelope

Spindles

Interphase; G1: The cell Grows
S: The DNA replicates
G2: The cell prepares for mitosis

Which stage of Mitosis? What happens?

Prophase; The centrioles move to opposite sides of the cell, The spindles form, The nuclear envelope disappears, Chromatin coils into chromosomes

Which stage of Mitosis?

Metaphase; The chromosomes line up across the middle of the cell and the spindles attach to each side of the chromosome

Which stage of Mitosis?

Anaphase; As the spindles retract back into the centrioles, the chromosomes are pulled apart to opposite sides of the cell

Which stage of Mitosis?

Telophase; Chromosomes are in two groups at opposite ends, the chromosomes unravel into chromatin, and new nuclear envelopes form around each group

Which stage of Mitosis?

Cytokinesis; The cytoplasm pinches in half, Cleavage, creates a cleavage furrow that deepens and eventually separates the cell into 2 daughter cells

Which stage of the Cell Cycle? What happens?

Yes

Are the daughter cells identical to eachother?

Yes

Are the daughter cells identical to the original cell?

Cleavage furrow

This forms as the cytoplasm pinches

cell plate

forms between the two new cells and eventually becomes the cell wall

Red: Centromere, Yellow: DNA, BLUE: Sister Chromatids

What is Red, Blue, and Yellow?

Anchorage Dependence

cells must be in contact with a solid surface to divide, this is called...

density-dependent inhibition

when cells stop dividing when they touch one another, this called...

turned on and off

that cell growth and division (the cell cycle) of a cell can be...

When you cut yourself, skin cells heal the cut by beginning to grow and divide, and healing occurs as the skin cells fill in the gap and stop when the cells touch.

example of density-dependent inhibition

growth factors

stimulates cells to divide, cells stop dividing when they run out of them

checkpoints

A stop after a step in the cycle that checks if the step has been completed properly, if not it will be fixed

G1, G2, and M

three major checkpoints...

G1

most important checkpoint

G0

If it doesn’t receive a go signal, it will exit the cell cycle,
switching into a non-dividing state called...

Non-dividing nerve, brain, and muscle cells

examples of cells in G0

the cell will continue the cell cycle and divide

If a cells receives a go at G1, what happens?

when a cell with a receptor protein responds to a growth factor, the growth factor bonds to the protein and triggers a transduction pathway. The signal is sent by proteins which overrides the stop signal and the cell moves on to divide.

Explain the signal transduction of growth factors.

DNA is monitored to make sure it's not damaged to cause a mutation which is dangerous to pass on to dividing cells.

During the G1 checkpoint, why is DNA monitored?

DNA

In what molecule are mutations found?

infections, radiation, tobacco use, and chemicals.

What can cause mutations in your DNA?

Abnormal

Cells that have mutations in them are called ___________ cells (or cancer cells)

When cells grow and divide uncontrollably and form masses.

How do abnormal cells form tumors?

Tumors can spread through the bloodstream, and create more tumors

How do tumors spread to other parts of the body?

Benign tumors aren't cancerous or disturb organ function. Malignant tumors are cancerous and disturb organ function.

What is the difference between benign and malignant tumors?

When a tumor enters the bloodstream and spreads through the circulatory system away from where it was originally.

What is metastasis?

Carcinomas

cancer of the skin, body, or lining of intestine

Sarcomas

cancer of the tissue, such as bone or muscle

Leukemia and Lymphoma

Cancer in the blood-tissues, such as bone marrow, spleen, and lymph nodes.

Cancer cells do not follow checkpoints, they continue to grow and divide regardless of mutations or overcrowed surfaces

Explain the relationship between cancer cells and checkpoints.

a treatment used to prohibit certain steps of the cell cycle so the cancer cells don't continue to grow and divide

How does chemotherapy work?

Apoptosis is the programmed death of cells. Apoptosis occurs when the hands and feet of a fetus develop, the cells that form the webs between the toes and feet go through Apoptosis and disappear.

What is apoptosis and give an example of when it occurs in your body?

Homolougous Chromosomes

one pair of chromosomes (one chromosome from each parent)

Karyotype

a picture of all the chromosomes in a cell

lined up in height order and numbered

How are homolougous chromosomes paired together?

autosomes

first 22 pair of chromosomes are known as…

sex chromosomes

last pair of chromosomes

XX

female at birth, the sex chromosomes are __

XY

male at birth, the sex chromosomes are __

Meiosis

the creation of gametes

gametes

name of sex cells

half

do gametes have half or all chromosomes?

Haploid

contain only a single set of chromosomes, and only a single set of genes

N

Haploid is represented by the letter

N=23

Haploid number for humans is

Diploid

contain both sets of parent chromosomes

2N

Diploid is represented by the symbol

diploid cells have all chromosomes and haploid cells have half the chromosomes

Difference between Diploid and Haploid cells

Fertilization

1 haploid gamete (egg cell) combines with another haploid gamete (sperm cell)

somatic cells

name of body cells

synapsis

process of pairing up matching chromosomes from each parent chromosome

tetrads

through synapsis homologues chromosomes form…

zygote, embryo, fetus, baby

developing stages of after fertilization

crossing over

homologous chromosomes exchange portions of their chromatids in a process called…

genes

segments of DNA on chromosomes

homologous chromosomes are pulled apart into opposite sides

what happens during Meiosis 1?

Interphase;

G1: cell grows

S: replicates DNA

G2: prepares for division

Prophase I; Homologous chromosomes form tetrads through synapsis, the chromosomes exchange their genes in crossing over, nuclear envelope breaks down, spindles form

Crossing-over produces new combinations of genes on the chromosomes, which is one of the reasons why siblings look different from each other

why don’t siblings look alike?

Metaphase 1; Pairs of homologous chromosomes line up in the middle of the cell

Anaphase 1; Homologous chromosomes are pulled apart to opposite ends of the cell by the spindles

Telophase 1 & Cytokinesis; the nuclear envelopes form around the groups of chromosomes and the spindles break down, 2 new daughter cells are formed

\

Sister chromatids are pulled to opposite ends of the cell

what happens during Meiosis 2?

Prophase 2; a new spindle forms around the chromosome and the nuclear envelope breaks down

Metaphase 2; chromosomes line up single file across the cell

Anaphase 2; Centromere divided and sister chromatids get pulled apart to opposite ends of the cell by spindles

\

Telophase 2 and Cytokinesis; each cells splits in 2 to make 4 haploid daughter sex cells that have half the number of chromosomes