1.4 science

Whats cell replication , compare eukaryotes and prokaryotes ?

 

Cell replication is critical

for both eukaryotes and

prokaryotes.

It allows existing cells

to produce new cells

allows existing cells to grow, develop and repair themselves

For mitosis list the stages ( in eurzakoyotic cell

Prophase

Metaphase

Anaphase

Telophase

 

How many stages does the eukaryotic cell have

eukaryotic cell cycle is composed of three stages including interphase, mitosis, and cytokinesis.

Mitosis

division of one cell into two identical cells

How does cell divison occur for mitosis and whats the purpose

Throufh mitosis which is one stage of cell cycle , occurs in every cell in our body . its to produce two genetically identical daughter cells from a single parent cell, enabling organism growth, tissue repair, and the replacement of old or damaged cells.

Interphase process before mitosis

the cell produces the substances needed and does its required job in the body. It also replicates all the DNA in its chromosomes. This is important as the new cells would not contain the correct genetic material to carry out their functions! Mitosis passes genetics from cell to cell.

Why is interphase in mitosis important

New cells would not contain correct genetic matirzal to carry out functions

FOurphases of mitosis ( PMAT)

1. Prophase : chromosome coil up and nucleus breaks down  , spindle fibres start to form

2. Metaphase : Chromosomes line up across middle of cell , the spindle fibres attach to side of chromosoe

3. Anaphase: spindle fibres pull away chromosome from centretowards either side of cell and elogates

4. Telophase: chromomes on each side are relased from spindle fibres and unwind , While nucleus reforms arounf them . The middle of cell pinch inwards .

cytokinesis

Cytokinesis : after the mitosis PMAT , cell splits  down in half , known ad cytokinesis , cytoplasm divides and the

organelles evenly distribute themselves before separating into two daughter cells.

The growth and repair of mitosis . What does mitosis additionally do throgh growth

•The process of mitosis is important as it allows growth and repair to occur

•Growth is not the cells themselves growing

•As the number of cells in a tissue increase, the size of the tissue increases

•

•The maximum growth of an organism is determined by its genes

How does  mitosis growth occur after cell division: 

•Cells are constantly dividing to replace cells that are damaged and old to ensure the organism can effectively perform functions needed for survival

•

•Some cells are replaced every few days (stomach, intestinal)

•Some last a longer time (liver)

•

•Not all body cells can be replaced, nerve and heart muscle cells cannot divide, so damage is permanent.

Due to the increasin number cell what does this affect due to growth after divison:

Causes tissues tp incrrwase the size of tissue causing organisim to grow .

damaged cell , how does it ensure healthy

 Cells constantly devide and replace cells that are damaged or old , cell division ensures cells are healthy and can perform the functions needed for survivial

 

Xells in stomac or intesties last few days due to exposed damage  

Whats an uncontrolled mitosis that causes disease (M)

 

 

 

A mutation : is a change in the structure of a gene, caused by alterations in DNA such as the substitution, deletion, insertion, or rearrangement of genetic material.

 

What happens when cells are mutated :

• cell’s instructions for normal division can be removed entirely.

• Without proper instructions, the cell begins to divide much more rapidly than normal.

When cells are changed/mutated what does this trigger :

• this rapid, uncontrolled division causes the cell to form dangerous tumours also called disease cancer.

• Changes (mutations) in these genes are the reason cancers occur in our bodies.

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