Topic 2: Cells & Control Flashcards
What is a cell cycle?
A series of stages where cells divide to produce new cells
When a cell isn’t dividing, it’s in interphase. What three things does the cell do before dividing?
- Grows in size
- Increases amount of sub cellular structures
- Duplicates DNA
What is mitosis?
The stage of the cell cycle when the cell divides.
What are the 5 phases of mitosis?
- Prophase
- Metaphase
- Anaphase
- Telophase
- Cytokinesis
What is prophase?
When chromosomes condense from DNA
The membrane around nucleus breaks down
What is metaphase?
Chromosomes line up across the equator of the cell
Spindle fibres attach to the centromere on the chromosome
What is anaphase?
Spindle fibres contract & pull apart the chromosome to the opposite sides of the cell
What is telophase?
Nuclear membrane forms around the two sets of chromosomes
What is cytokinesis?
2 genetically identical diploid cells daughter are produced
How to remember stages of mitosis?
Pee MAT Cat
What does mitosis do?
Allows organisms to grow or replace cells that have been damaged
What are the three methods of growth?
- Cell differentiation - when a cell changes to become specialised for its job
- Cell division - mitosis
- Cell elongation (plants only)
What is a percentile chart?
They’re used to monitor a child’s growth
Used to see if there should be a cause for concern for the baby
E.g. 50th percentile = the size that 50% of children will reach at a certain age
What are stem cells?
Undifferentiated cells that divide to produce lots more stem cells, these can differentiate into many other types of cells
Can be grown in a lab and made to differentiate
What can stem cells from adult animals become?
A limited amount of cells
What can stem cells from a human embryo become?
Any kind of human cell
There are moral and ethical arguments against the use of these
What can stem cells from plant meristem become?
Any kind of plant cell
What are some potential benefits of the uses of stem cells in becoming differentiated for medicine?
Could replace cells that have been damaged by disease or injury
E.g. cardiac muscle cells treat heart disease
What are some potential risks of the uses of stem cells in becoming differentiated for medicine?
Tumour development
Disease transmission (if the donor stem cells are infected with a virus)
Rejection by patients immune system
What are the 3 parts of the brain?
- Cerebrum
- Cerebellum
- Medulla oblongata
What is the role of the cerebrum?
Controls: movement, intelligence, memory, language & vision
2 parts of the cerebrum (hemispheres) - right hemisphere controls movement of the left side of the body & left hemisphere controls movement of the right side of the body
What is the role of the cerebellum?
Controls: muscle coordination & balance
What is the role of the medulla oblongata?
Controls: unconscious activities
What is the CNS?
Consists of the brain and spinal cord
CNS = centralised nervous system
Why is treating and investigating the CNS and brain difficult?
Complex and delicate
CNS nervous tissues cannot be repaired
Operating on the brain or spinal cord risks permanent damage
Tumours can grow in parts of the brain that are hard to access