Cell Division Flashcards
What are the primary purposes of cell division?
Growth, replacement of cells, repair of damaged tissue
New cells carry the same genetic information to perform the same jobs.
What is contained within a cell’s nucleus?
Chromosomes
Chromosomes house genes, which have the instructions for making new cells and tissues.
What is a gene?
A section of DNA that controls a characteristic of the body
Genes are grouped together in chromosomes.
How many chromosomes do humans have in their body cells?
46 chromosomes in 23 pairs
One chromosome in each pair is inherited from the father and one from the mother.
How many chromosomes do sex cells (gametes) contain?
23 chromosomes
Sex cells have only one chromosome from each pair.
What is the cell cycle?
A series of stages that body cells go through to divide
It includes mitosis to produce identical cells.
What does mitosis produce?
Two identical cells with the same chromosomes and genetic information
It is essential for growth, development, and replacement of damaged cells.
What happens during asexual reproduction?
Offspring cells are produced by mitosis from parent cells
Offspring contain exactly the same genes as their parent.
What are the three main stages of the cell cycle?
- Cell growth and DNA replication 2. Mitosis 3. Cytoplasm and cell membrane division
Each stage is crucial for producing identical daughter cells.
What occurs in stage one of the cell cycle?
Cells grow, replicate DNA, and increase subcellular structures
This prepares the cell for division.
What happens during mitosis?
One set of chromosomes is pulled to each end of the cell and the nucleus divides
This is stage two of the cell cycle.
What occurs in stage three of the cell cycle?
The cytoplasm and cell membranes divide to form two identical daughter cells
This completes the cell division process.
What is differentiation in the context of cells?
The process by which unspecialised cells become specialised to perform specific functions.
What type of cells are unspecialised and can become any type of cell?
Stem cells.
How do specialised animal cells typically divide?
By mitosis, forming the same type of cell.
What happens to specialised cells that cannot divide?
They are replaced by adult stem cells.
Which type of cells cannot be replaced in adults?
Nerve cells.
In mature animals, what is the primary reason for cell division?
Repair and replacement of damaged cells.
What are meristems in plants?
Active regions in stems and roots where undifferentiated cells are formed.
How do plant cells differ from animal cells in terms of differentiation?
Plant cells can continue to differentiate throughout their lives.
What is cloning in the context of plants?
Producing identical offspring from a tiny piece of lead tissue.
What happens to plant cells during cloning?
They become unspecialised and undergo mitosis before differentiating into needed tissues.
Why is cloning animals more difficult than cloning plants?
Animal cells differentiate permanently early in embryo development.
Fill in the blank: In plants, differentiation is not _______.
permanent.
