4.1.2 Cell Division Flashcards
What are chromosomes made of?
DNA molecules.
What do chromosomes carry?
A large number of genes.
How are chromosomes found in body cells?
In pairs.
What is the series of stages that cells divide in called?
The cell cycle.
What happens to genetic material during the cell cycle?
It is doubled and then divided into two identical cells.
What must a cell do before it divides?
Grow and increase the number of sub-cellular structures like ribosomes and mitochondria.
What happens to DNA before mitosis begins?
It replicates to form two copies of each chromosome.
What happens during mitosis?
One set of chromosomes is pulled to each end of the cell, and the nucleus divides.
What happens after the nucleus divides?
The cytoplasm and cell membrane divide, forming two identical cells.
Why is mitosis important in multicellular organisms?
It is important for growth and development.
What is a stem cell?
An undifferentiated cell that can give rise to many more cells of the same type and differentiate into other cell types.
Where are stem cells found in humans?
In embryos and adult bone marrow.
What can stem cells from human embryos do?
They can be cloned and made to differentiate into most types of human cells.
What types of cells can adult bone marrow stem cells form?
Many types, including blood cells.
Where are stem cells found in plants?
In meristem tissue.
What can meristem stem cells do?
Differentiate into any type of plant cell throughout the life of the plant.
How might stem cells be used in medicine?
To treat conditions like diabetes and paralysis.
What is therapeutic cloning?
Producing an embryo with the same genes as a patient so its stem cells won’t be rejected.
What are potential risks of stem cell use?
Transfer of viral infection and ethical/religious objections.
How are plant stem cells used in agriculture?
Cloning rare species to prevent extinction.
Producing disease-resistant crops in large numbers.
