Recall the worst cut you have ever had in your life. Record the following info in

your notes-> •Think of how the cut happened•Remember the healing process

•Locate the scar (if any) and make observations

Reproduction is the biological process by which new individual organisms are produced from pre-

existing organisms.

These new individuals are referred to as

_______________OFFSPRING

These pre-existing organisms are referred to as _________Parents/Parent cells

The known methods of reproduction are broadly grouped into two main

types: sexual and asexual.

Reproduction is a fundamental feature of all known life; each individual organism exists as the result of reproduction.

• an individual can reproduce without involvement with another

individual of that species. • The division of one cell into two

daughter cells is an example of asexual reproduction.

• Not limited to single-celled organismsMost plants have the ability to reproduce

asexually.

• requires the involvement of two individual’s cells, typically

one of each sex.• Normal human reproduction is a

common example of sexual reproduction.

One parent cell Two parents cells

________offspring _________offspringIdentical Similar

The process by which a cell duplicates the chromosomes in its cell nucleus, in order to generate two, identical, daughter nuclei

the division causes the daughter cells (each) to have the genetic equivalent of

the parent cell.

How does mitosis effect chromosome number?

Example: Human chromosome number is ____46

Which cells in the human body carry out

mitosis?

Examples: skin cells, hair cells, nerve cells, etc.

These cells are called Somatic CellsAka body cells

The process of mitosis involves a series of complex and highly regulated

steps

The sequence of events is divided into phases

The end of the process and start of another is signified by the complete division of the

cell membrane CALLED CYTOKINESIS

These stages are interphase, prophase, metaphase, anaphase

and telophase.

Looking at the phases, place them in order of how the process of mitosis occurs.

A

B

C

D

C

•When the chromosomes are replicated/duplicated•Periods of cell growth, to prepare for cell division

• Each duplicated chromosome is seen as a PAIR of sister chromatids joined by the centromere

The spindle fibers forms between the two pairs of centrioles as they migrate to opposite sides of the cell.

• The nuclear envelope disappears at the end of prophase

•The centrioles are at opposite poles of the cell.

• The chromosomes become arranged on a plane equidistant from the two poles. Chromosomes line up in the middle

Anaphase begins when the duplicated chromosomes separate, and the now-daughter chromosomes begin moving AWAY toward opposite poles of the cell due to the action of the spindle.

• At the end of anaphase, a complete set of chromosomes has assembled at each pole of the cell.

• The chromosomes begin to uncoil and assume the characteristics of interphase.

• A nuclear envelope reforms around each chromosome set, the spindle disappears, and the nucleolus reforms. Nuclear division by mitosis is complete at this point.

•equal division of the cytoplasm,

• In animal cells, cytokinesis involves the pinching of the cell membrane into two.

•In plant cells, cytokinesis involves the formation of the cell plate which develops into the cell wall

Label the phases shown (1-3)

13

2

•A.K.A. Gametes•Examples: human egg and sperm cells•Function is to fertilize•Used to carry out sexual reproduction•Have _____ chromosomes each23

Created by the process of __________MEIOSIS

•Meiosis is the type of cell division by which gamete cells (eggs and sperm) are produced. •Meiosis involves a reduction in the amount of genetic material.•A.K.A. reduction division

To maintain normal chromosome number once fertilization occurs

2323 46

Meiosis consists of two successive nuclear divisions with only one round of

DNA replication.

92

4646

23232323

46 Parent cell

4 Daughter cells

Meiosis IMeiosis I•Interphase•Prophase•Metaphase•Anaphase•Telophase

Meiosis IIMeiosis II•Prophase II•Metaphase II•Anaphase II•Telophase II

To reduce chromosome number

START END

2n = ____Called the Diploid #

46 n = ____Called the Haploid #

23

•Animals produce gametes directly through meiosis in organs called gonads.

•Males and females of a species that reproduces sexually have different forms of

GAMETOGENESIS (formation of GAMETOGENESIS (formation of gametes)gametes)

2 Types•spermatogenesis (male)

•oogenesis (female)