CELL REPRODUCTION: Mitosis & Meiosis

A PARENT CELL divides into 2 _______________.
Cells must divide or stop growing because its volume increases faster than its surface area.
Some bacteria may divide every _______________ min.
Human cells may take _______________ hours to divide.

_______________ REPRODUCTION: the reproduction of offspring from one parent. The offspring has genetic material _______________ to the parent.

1. _______________: a cell splits in two. (this is the simplest form of asexual reproduction)

2. _______________: chromosomes replicate (copy) and a protective wall forms around the new nucleus. Spores can remain inactive for long periods of time.

3. _______________: cells divide into two cells of unequal size. The smaller cell, the bud, pinches off.

4. _______________ reproduction: runners, leaves, or stems of plants may develop into new plants, separate from the parent.

5. _______________: the development of new animals from its parts.
Example: starfish

_______________ REPRODUCTION: the formation of a new individual from the union of two specialized cells. Offspring have combined characteristics from each parent.

_______________: specialized sex cells
Sperm cell - _______________ gamete
Ovum (egg) - _______________ gamete
_______________ - the joining of sperm and egg
_______________ - a fertilized egg
_______________ - body cells (anything other than the sex cells)
Somatic cells have _______________ chromosomes, _______________ pairs.

MITOSIS

THE CELL CYCLE: the normal growth pattern of a cell. It consists of Interphase (including the G1 phase, S stage, and G2 stages), and mitosis.

_______________ the period of growth and development between divisions. During this time the chromatin material is long and thread-like. It cannot be seen by a light microscope at this time.
Interphase is not considered a part of mitosis.

_______________ stage: a period of rapid growth and development.
_______________ stage: Synthesis stage - the chromosomes are copied during this time.
_______________ stage: a second period of growth

_______________:
1. Chromosomes coil into short _______________.
Each chromosome consists of two shortened rods called _______________ that are held together by the _______________. Each chromatid is identical.
2. _______________ disappear.
3. Centriole doubles and separates.
4. _______________ fibers form.
5. Nuclear membrane _______________.

_______________:
Chromosomes are lined up along the _______________ of the cell.

_______________:
Chromatids _______________ and pull apart. Each chromatid is now called a chromosome. They move _______________ the opposite poles.

_______________:
1. Spindle fibers _______________.
2. Nuclear membrane _______________.
3. Nucleoli reform.
4. Chromosomes uncoil and _______________.

_______________: the divsion of the _______________.
Usually begins during telophase.
Animal cells pinch apart.
Plant cells form a CELL PLATE.

MEIOSIS

_______________ is the process that reduces the number of chromosomes in sex cells to half the number in somatic cells.

_______________ NUMBER: a full set of chromosomes
_______________ NUMBER: half a set of chromosomes, one from each pair.

Meiosis is similar to mitosis. Chromosomes double before beginning prophase. The cells go through prophase, metaphase, anaphase, and telophase. But they go through them twice. The chromatids divide differently from mitosis.

PROPHASE I: _______________ occurs ,_______________ (similar) chromosomes pair up and wrap around each other. This forms a _______________.

METAPHASE I: _______________ line up at equator.

ANAPHASE I: homologous _______________ and go to opposite poles but centromeres do not separate.

TELOPHASE I: chromosomes reach poles. _______________ occurs.

At the end of Meiosis I each cell contains two copies of one member of the homologous pair.

Chromosomes do not _______________ before Prophase II.

PROPHASE II: new _______________ form
METAPHASE II: _______________ line up
ANAPHASE II: _______________ separate
TELOPHASE II: new _______________ and cells form.

Each cell has _______________ the chromosomes of the parent cell.