How do little elephants grow up to be BIG elephants?
Reproduction is the process by which organisms produce more of their own kind. Think about it – Without reproduction, all life on earth would no longer exist.
Only one parent is involved. Offspring are genetically identical to their parents. All cells that come from a single cell are genetically identical to it and to each other; they are all clones.
We have two types of cells in our body a) Gamete cells – sperm and egg cells b) Somatic cells – all body cells except reproductive cells (examples- skin cells, hair cells, nerve cells etc)
All somatic cells reproduce by a process called MITOSIS. This is ASEXUAL reproduction. All sexual cells are produced by a process called MIOSIS. This is SEXUAL reproduction
The process of asexual reproduction begins after a sperm fertilizes an egg.
Skin cancer - the abnormal growth of skin cells - most often develops on skin exposed to the sun. Cell that reproduce by asexual reproduction reproduce constantly.
We are going to look at how somatic cells reproduce so that each new cell has the same complete set of instructions (DNA). That process is called
11 Asexual Reproduction Mitosis Mitosis is the process in which the nucleus divides to form two new nuclei. The two new cells created are identical.
A chromosome is a structure composed of DNA.
Each chromosome has a different form. Humanes have 46 chromosomes in the form of 23 pairs found in the nucleus of each of our cells.
Chromosomes are particularly visibles during the division process of the cell. Different species have different numbers of chromosomes. - Humans have 46 - Chicken have 78 - Mosquito have 6 - Rice has 24
Segments of DNA determine a particular hereditary trait. A gene is on a specific spot on each chromosome.
We can divide the life cycle into four parts: › 1) Growth (G1) › 2) The synthesis and replication of chromosomes (S) › 3) Preparation for division (G2) › 4) Mitosis (M)– cell division
Cell Cycle and Mitosis [3D Animation] ZQkmooyPk
Mitosis: The Amazing Cell Process that Uses Division to Multiply! wcwSZIfKlM
Animated Mitosis Cycle Interphase Prophase Metaphase Anaphase Telophase & Cytokinesis
Interphase Anaphase Telophase Metaphase Prophase Cell division
G1 M M G2 S S Interphase
Chromosomes are copied (# doubles) Chromosomes appear as threadlike coils ( chromatin ) at the start, but each chromosome and its copy( sister chromosome) change to sister chromatids at end of this phase CELL MEMBRANE Nucleus Cytoplasm
Replication Centromere Identical chromatide Chromatide Anaphase Two identical chromosomes Chromosome The centromere is what holds these two identical chromosomes together.
Animal Cell Plant Cell Photographs from:
chromatin
Mitosis begins (cell begins to divide) Centrioles (or poles) appear and begin to move to opposite end of the cell. Spindle fibers form between the poles. Centrioles Sister chromatids Spindle fibers
Animal Cell Plant Cell Photographs from: Spindle fibers Centrioles
Chromatids (or pairs of chromosomes) attach to the spindle fibers. Centrioles Spindle fibers
Animal Cell Plant Cell Photographs from:
Chromatids (or pairs of chromosomes) separate and begin to move to opposite ends of the cell. Centrioles Spindle fibers
Animal Cell Plant Cell Photographs from:
Two new nuclei form. Chromosomes appear as chromatin (threads rather than rods). Nuclear membrane reforms Mitosis ends. Nuclei Chromatin
Animal Cell Plant Cell Photographs from:
Cell membrane moves inward to create two daughter cells – each with its own nucleus with identical chromosomes. Division of the cytoplasm
In plant cells, a cell plate forms across the centre of the cell, forming a new cell wall between the two new cells.
Mitosis Click the picture above!
Animal Mitosis -- Review Interphase Prophase Metaphase Anaphase Telophase Interphase
Plant Mitosis -- Review Interphase Prophase Metaphase Anaphase Telophase Interphase
I I nterphase P P rophase M M etaphase A A naphase T T elophase C C ytokinesis IPMATC I Pray M ore At T he Church
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