Topic 2 Flashcards
Anaphase
Stage of mitosis when separated chromosomes move away from each other
Asexual reproduction
Producing organisms from one parent only.
Genetically identical to the parent
Cancer cell
Cell that divides uncontrollably
Cell cycle
Sequence of growth and division in cells
Mitosis & interphase
Cytokinesis
When the cytoplasm of the cell is separated and the cell membrane is pinched to divide the cell into 2 daughter cells
Daughter Cell
New cells produced by cell division
DNA replication
Copying of DNA in a cell
Interphase
Stage when cell prepared itself to divide, DNA replication takes place.
Makes more sub-cellular structures
Metaphase
Stage of mitosis when chromosomes line up in middle of cell
Mitosis
Process of cells dividing into 2 identical daughter cells, genetically identical also to the parent
Prophase
Stage of mitosis when the nucleus begins to break down and spindle fibres appear
Spindle fibre
Filament formed during mitosis to help separate chromosomes
Telophase
Chromosomes arrive at opposite ends of cell and nucleus membrane forms
Percentile
A 1/100 division of a group
Differentiate
To change into different types, e.g., meristem cells differentiate to become xylem cells or root hair cells
Elongation
When something gets longer
Meristem
A small area of undifferentiated cells in a plant
Root hair cell
Cell found on surface of plant roots that has a large surface area to absorb water
Xylem cell
Cells that join with other xylem cells to form long, thick walled vessels after they die.
Carry water and dissolved mineral salts through the plant
Adult stem cell
Stem cell found in specialised tissue that can produce more of the specialised cells in that tissue for growth and repair
Rejection
When the immune system attacks and kills cells and tissue
Axon
Long extension of a neurone that carries an impulse away from dendron or dendrite towards other neurones
Axon terminal
Small ‘button’ at end of branches that leave an axon
CNS
Central Nervous System
Brain and spinal cord
Dendrite
A fine extension from a neurone which carries impulses
Dendron
Large, long extension of a sensory neurone that carries impulses from dendrite to axon
Myelin sheath
Fatty covering around axons of neurones.
Speeds up transmissions of impulses
Helps to insulate
Neurone
Cell that transmits electrical impulses
Nerve cell
Neurotransmission
Passing impulses
Neurone to neurone
Receptor cell
Cell that receives a stimulus and coverts it into an impulse to be sent to the brain - spinal cord
Sense organ
Organ that contains receptor cells
Sensory neurone
Neurone that carries impulses from receptor cells towards CNS
Stimulus
Change in a factor detected by receptors
Effector
Muscle or gland in the body that performs an action when an impulse is received from nervous system is received
Motor neurone
Neurone that carries impulses to effectors
Neurotransmitter
Substance that diffuses across the gap between 2 neurones at a synapse
Reflex arc
Neurone pathway consisting of sensory neurone passing impulses to a motor neurone
Relay neurone
Short neurone in spinal cord and brain, linking with sensory, motor and other relay neurones
Synapse
Where 2 neurones meet - tiny gap where electrical impulses cannot be transmitted, so are changed into chemical impulses
