Biology Quiz - Cell Division, Mitosis, Meiosis, Cancer, Cell Differentiation

Cell Division

Creation of new cells that are identical to each other. It is a form of asexual reproduction.

Diploid Number

Total number of chromosomes/Complete set of chromosomes.

Parent Cell

A cell that divides into two daughter cells.

Daughter Cells

Two cells divided from a parent cell, they are identical and diploid.

Somatic Cells

Body cells in which Mitosis occurs. EX: white/red blood cells, skin cells, cardiac cells

Asexual reproduction

Reproduction done without sex cells/gametes

Eukaryotes

A type of cell that has a nucleus and goes through the cell cycle.

Cell Cycle

The process of a cell’s life.

Steps: Interphase → Mitosis → Cytokinesis

Interphase

The longest phase of the cell cycle. Cell growth occurs and DNA/Chromosomes are duplicated.

Steps: G1 → S →G2

Also includes G0

G1

When cell growth occurs. Stimulates cell signals with cyclin, and replicates organelles.

Checkpoint

Used to make sure everything with the cell is in order.

G1 Checkpoints

Is the DNA damaged?

Is the signal ok?

Done using CDK, an enzyme, with cyclin as a substrate

G0

A pit stop for some cells. They stay here until they are signaled

to move on. Some cells stay here permanently. EX: neurons, cardiac cells.

S (Synthesis) phase

Where DNA is duplicated.

S phase checkpoint

Did the DNA duplicate correctly?

G2

Higher amount of signals are sent (cyclin)

Cell growth continues

Specific organelles get ready for the next phase.

Mitosis

When the nucleus is divided.

Prophase

Chromosomes are visible, microtubules create spindle fibers.

Metaphase

Chromosomes are at the middle of the cell, held there by spindle fibers.

Metaphase checkpoint

Did the spindle fiber grab the chromosomes?

Anaphase

Chromosomes are broken apart, and are separated to opposite ends of the cell.

Telephase

One cell with two nuclei

Cytokinesis

Cytoplasm is divided between the cells. Results with two identical daughter cells with a diploid number.

Differentiation

The process of cells getting specific jobs in the body. It occurs through different genes being expressed in the DNA.

Embryonic Stem Cells

Undifferentiated cells created from Meiosis that can be assigned any job. These cells are immortal, and often used in science.

Pluripotent

A cell with the capability to be any type of cell

Zygote

A single celled type of cell created from an egg and sperm. It has a diploid number.

The 8 cell mark

The first phase of cell differentiation. A blatula is formed. Cells are multipotent in this phase.

Multipotent

When cells begin to get a specific job.

Cell jobs

1. Ectoderm

2. Mesoderm

3. Endoderm

Ectoderm

Cells on the outside of the body/sensory cells

EX: skin, eyes, neurons

Mesoderm

Cells in the middle/the rest of the body

EX: Blood, bones, etc

Endoderm

Cells responsible for internal organs

Telomeres

Caps on chromosomes that are used as protection during the DNA duplication phase (S phase).

The amount of telomere will reduce as it duplicates, especially when the cell has become differentiated.

Does not carry any type of gene

When the telomere is absent, the chromosome is open to damage

Cancer

When DNA is damaged the cell’s reproduction is affected.

Causes uncontrolled cell growth

Uncontrolled cell growth

The cell cycle moves through at a quicker rate. the cancer tricks the cell to ignore checkpoints once, and then all checkpoints start to become ignored.

Immortal Cells

Embryonic stem cells and HeLa cells

Made by telomeres

The enzyme, telomerase, rebuilds the telemeres

Normal cells

Cell grows according to available area, utilizinf available nutrients equally.

Cancer Cells

Have an abnormal look, cells grow on top of one another, pulls all available nutrients to themselves (starves neighboring cells)

Pro-oncogene

Starts/controls cell divison

Mutation = oncogene/out of control cell division = checkpoints are ignored = cancer

Angiogenesis

Cancer cells signal for new blood vessels to reach it

Will provide nutrients to the cancer + transports it around the body

Metastasis

When cancer spreads around the body through seeping into blood vessels it attracts.

Gametes

Sex cells (egg + sperm)

Meiosis

The way gamete cells reproduce

Not cyclic

Gametes do not return to interphase

Meiosis goals

Haploid gametes (combine with other gamete for a zygote diploid)

Genetic variation in offspring, higher form of adaptation

Homologous Chromosomes

Paired chromosomes based on similar alleles (eye color, hair color, etc)

One from mom, one from dad

Form of gene can be different (EX: blue eyes + brown eyes)

Meiosis 1

The first part of steps in meiosis

Prophase 1

Homologous chromosomes are tightly packed together, a synapse occurs

The genes will swap sections in the two chromosomes (crossing over = genetic variation)

• Can swap anywhere on the gene

Centromere

Where microtubules attach to a chromosome

Chromatid

One half of a full chromosome

Metaphase 1

Homologous chromosomes line up at the middle of the cell

The way they line up at the middle is random

Spindle fibers attach to the centromere

Independent Assortment

The way chromosomes line up randomly at the middle of the cell in metaphase 1. A second form of genetic variation.

Anaphase 1

Homologous chromosomes are split apart. Individual chromosomes are moving to the poles of the cell

Telephase 1/Cytokinesis 1

Two new nuclei are present in respective daughter cells with a haploid number.

Meiosis 2

Two cells divided like they were in mitosis without returning to interphase

At the end, four daughter cells are formed

• Haploid cells

• Genetically unique

Spermtogenesis

Meiosis in the testes, creation of sperm.

Occurs from puberty to death.

4/4 cells/sperm created in meiosis are viable

Oogenesis

Meiosis in the ovaries, creation of eggs

Born with the amount of eggs for a female lifetime (in the utero)

Occurs from puberty to menopause

¼ cells/eggs created from meiosis are viable