2.1 Producing New Cells Flashcards
Describe the sequence of events in mitosis.
- Just before a cell divides, each chromosome doubles to form the two identical chromatids joined by a centromere.
- The chromosomes shorten and thicken and become visible.
- The nuclear membrane breaks down.
- The spindle fibres attach to each centromere and move the chromosomes to the equator of the cell.
- The spindle fibres shorten and pull the chromatids apart.
- Chromosomes move to opposite ends of the cell (the poles of the cell).
- Nuclear membranes form and the cytoplasm divides.
- There are now two new cells each with the same chromosome complement as the original cell.
What does mitosis do?
Mitosis provides new cells for growth and repair of damaged cells.
Describe the importance of mitosis in maintaining the diploid chromosome complement.
It is important as it ensures that the diploid chromosome complement is maintained and the genetic information in the daughter cells is identical to the parent cell.
What does the specialisation of cells lead to?
The specialisation or cells leads to the formation of a variety of cells, tissues and organs.
What is tissue made up of?
Tissue is made up of similar specialised cells carrying out the same broad function.
What is an organ made up of?
Organs are made up of a group of different tissues working together.
What is the name of the groups that organs are organised into?
Organs are organised into groups called organ systems.
What is the hierarchy that exists in multicellular organisms?
Cells - tissues - organs - systems.
What are stem cells in animals?
Stem cells in animals are unspecialised cells which can divide to self renew.
Describe what stem cells have the potential to become.
Stem cells have the potential to become different types of cells and are involved in growth and repair.
