What do histones do?

coil and uncoil DNA

What is the longest part of the cell cycle?

Interphase

What are the 3 stages of interphase?

G1 (gap phase 1)

S (synthesis)

G2 (gap phase 2)

What is the G1 phase

and what happens during it?

Gap phase 1: growth and metabolism

What is the S phase and

what happens during it?

Synthesis: DNA replication

What is the G2 phase

and what happens during it?

Gap 2 phase: Growth and metabolism

What are the double stranded chromosones that appear after replication called?

Sister Chromatids

What are sister chromatids held together by?

centromere

Is the DNA of sister chromatids the same or different?

The same/identical

4 stages of Mitosis in order

Prophase, Metaphase, Anaphase, Telophase

(PMAT)

During what stage of mitosis does the chromatin coil and a spindle forms?

Prophase

During what stage of mitosis do the chromosomes move the the middle?

Metaphase

(they met in the middle!)

During what phase of mitosis do the sister chromatids separate and move towards the centrosome poles?

Anaphase

What type of cell division occurs in somatic (body) cells?

Mitosis

What type of cell division occurs in the reproductive organs?

Meiosis

What is a sex cell called?

gamete

What happens to the total number of chromosomes during mitosis?

Remains the same, all genes replicated

What happens to the total number of chromosomes after meiosis?

Reduces by half

(Such as 46 total from one human parent, down to 23 given to offspring. Offspring has total of 46: 23 from each parent.)

In meiosis what is a cell with one set of chromosomes?

Haploid

In meiosis what is a chromosome with two sets of chromosomes?

Diploid

What is cytokinesis?

Process of dividing cytoplasm

While animal cells have a cleavage furrow during cytokinesis, plant cells have a ________

Cell Plate

What type of cell division is used during asexual reproduction?

Mitosis

Name 4 processes involving

mitotic cell division?

growth

wound healing

repairing tissues

embryonic development

What are growth factors?

things that stimulate or stop cell division

What is a fertilized cell called?

Zygote

How many sets of chromosomes

does a fertilized cell have?

2: one from each parent

Which cell division process produces genetic variability (mitosis or meiosis)?

Meiosis

How many daughter cells are

produced during mitosis?

2 (cells identical to parent cell) 

How many daughter cells

are produced during meiosis?

4 haploid cells 

(half the chromosomes as parent cell)

In both meiosis and mitosis there is

_________  prior to division. 

DNA replication

What is crossing over?

Swapping of similar gene segments

between chromosomes

What phase does

crossing over occur during?

Prophase

Does crossing over occur in

mitosis or meiosis?

Meiosis

What is synapsis?

The pairing of

homologous chromosomes

During which stage does cytokines occur?

Telophase

What happens to the spindle

and chromosomes during telophase?

The spindle disintegrates

and the chromosomes uncoil

What is nondisjunction?

When there is a faulty separation

of homologous chromosomes,

usually during meiosis.

When plants go through meiosis

they form _______

Spores

In plants, a diploid zygote

turns into what?

Sporophyte

Since there is less genetic variability,

what would be an advantage to

asexual reproduction?

It does not take another organism,

no extra energy expended

What is the function of mitosis?

To ensure and exact duplicate copy of DNA

gets into each new daughter cell

formed during division

What is the function of meiosis?

To reduce the number of chromosomes to half during gamete (sex cell) formation.

During which phase of mitosis

does the cell elongate?

Anaphase

What occurs during the prophase stage of meiosis that does not occur during that stage of mitosis?

There are no synapsis and no crossing over

during prophase in mitosis.