Topic 2: Cells And Control Flashcards
What happends in Interphase?
Cells grow+replicates its dna
What happens in prophase?
Nucleur membrane breaks down
What happenss in metaphase?
Chromosomes line up
What happens in anaphase?
Spinal fibers split chromosomes and pull one chromatid in either side of the cell
What happens in telophase?
Cell is nearly done dividing and it starts to reestablish its normal structure as cytokinesis ( division of the cell) takes place
Purpose of mitosis? (3)
1)growth:produce new cells
2)repair:replace damaged/dead cells
3)asexual reproduction:produce offspring genetically identical to parents
Define cancer
Change in cells that lead to uncontrolled cell division
Describe two daughter cell
Identical sets of chromosome that result in the formation of two genetically identical diploid body cells
Why is differentiation important?
Allow cells to specialise and perform specific functions in an organism
Function of embryonic stem cells?
Differentiate into any cell type
Disadvantage of adult stem cells
Only differentiate into limited cell types
What is differentiation
Process by wich a cell becomes specialised cells with specific functions
What are specialised cells
Cells that have specific function or structure to carry out a specific task
What are meristem cells? Where are they found?
Unspecialised cells that differentiate into cells needed by the plant in region where growth is occurring like the shoots ot roots
Disadvantage of Stem cells?(3)
1)body imune systemmight reject it
2)stem cells might turn into cancer cells
3)transfer infection
Disadvantage of embryonic stem cells
1)body imune system might reject it
2)limited supply(difficult to find a donor)
3)cancer cells
What are sensory receptors
Nerve ending that sends signal to the CNS when stimulated (triggered)
What are sensory neurones
Carry electrical signals towards the CNS
What are relay neurones l
Found between sensory and motor neurons to communicate
What are motor neurons
Carry nerve impulses away from the CNS (maybe to muscle cells to contract)
What is a synapse
Two points that allow signals to pass between neurons
What is a reflex arc
Nerve pathway followed by a reflex action stimulis->receptor->sensory neurone->relay neurone
Function of axon, dendron, myelin sheath
1)Axon:transmit information to different neurones
2)Myelin sheath:allow impulses to transmit quickly and efficiently along the nerve cell
3)Dendron:receive information from other neurones
Role of neurotransmitters
Cause production of an electrical impulse in the next neurone
