Unit 2: Producing New Cells From Achieve Flashcards
Describe the events of mitosis
The main events of mitosis are:
In the original parent cell, the chromosomes replicate and double. Forming 2 identical chromatids joined in the centre by a centromere.
The nuclear membrane breaks down and the chromosomes shorten and thicken, becoming visible under a microscope.
The chromatids line up along the equator of the cell.
Spindle fibres attach to the chromatids.
Spindle fibres shorten pulling the chromatids apart to opposite poles of the cell.
The cytoplasm divides and a nuclear membrane forms.
2 diploid cells produced, containing the same genetic information as the original parent cell.
Describe a diploid cell
A diploid cell had two matching sets of chromosomes.
Most cells (the exception being the gametes) in the human body are diploid. They contain 2 sets of 23 chromosomes, giving a total of 46 chromosomes.
Both sets are replicated during mitosis.
Explain the importance of mitosis
Mitosis maintains the diploid chromosome complement of the new cells, providing the body with new cells that can be used in growth and repair.
Describe a stem cell and how they are used in animals
A stem cell in an animal is an unspecialised cell that can divide to self-renew (produce more stem cells) or become specialised. They have the potential to become any cell type in the body.
Stem cells are used in growth and repair.
State where stem cells are found
There are 2 types of stem cell:
Embryonic stem cells are taken from an embryo at a very early stage.
Tissue stem cells are found in the body throughout life.
Explain the importance of the specialisation of cells
Cells become specialised to give rise to a variety of cells, each with a particular function.
Describe the role of an organ explaining the term tissue, organ and organ system
A tissue is a group of cells.
An organ is a group of tissues.
An organ system is a group of organs.
An organ contains cells specialised for a particular function and groups of organs work together to form systems.
State the hierarchy of organ systems
Cells → Tissues → Organs → Organ systems
