Topic 2 Flashcards
Adult Stem Cells
Stem cells that can differentiate into a limited range of cell types
Asexual Reproduction
A form of reproduction involving a single parent that creates a genetically identical offspring
Axon
A long fibre that conducts nerve impulses away from the cell body
Cancer
A non-communicable disease caused by changes in the cell that lead to uncontrolled growth
Cataract
A cloudy patch that forms on the lens preventing light from entering the eye
Cell Differentiation
The process where a cell becomes specialised for its function
Cell Elongation
The process which cells expand and enlarge enabling the growth of a plant.
Central Nervous System
The brain and spinal cord
Cerebellum
The region of the brain the coordinates muscles and non-voluntary movement. (Eg: Balance and Posture)
Cerebral Hemisphere
One half of the cerebellum, each half controls corresponding half of the body
Cerebrum
The largest region of the brain made of 2 hemispheres. Responsible for movement, memory, intelligence, language and vision.
Chromatid
One ‘arm’ of a replicated chromosome
Chromosome
A long coiled molecule of DNA that carries genetic information in the form of genes
Colour Blindness
A deficiency of the eye making it difficult to distinguish between colours.
Cone Cells
Cells found in the retina that are sensitive to high light intensity (bright lights) and detect different colours.
Cornea
The transparent out layer that reflects light entering the eye.
CT Scan
A imaging technique that uses X-Rays to make a detailed imagine of internal organs.
Dendrites
Short, branched extensions of dendrons that provide large surface areas to receive nervous impulses from other neurones
Dendron
Branched extension of nerve cell body that connects to other neurones and carries impulses towards the body
Diploid Cell
A cell that contains 2 copies of each chromosome
Effector
An organ, tissue or cell that produces a response to a stimulus
Embryonic Stem Cells
Stem cells found very early in embryos that are unspecialised and capable of differentiating into any cell type
Eye
A sense organ containing receptors sensitive to light intensity and colours
Growth
An increase in mass or size
Haploid Cell
A cell that contains a single copy of each chromosome
Iris
A pigmented ring of muscles that controls the size of the pupil to alter how much light enters the eye
Lens
A transparent biconvex structure that refracts light focusing it onto the retina.
Long-Sightedness
A defect of the eye where nearby objects appear out of focus due to convergence of light rays behind the retina. This occurs when the eyeball is too short or the less is less elastic. This is fixed using a convex lens.
Medulla Oblongata
The region of the brain that controls unconscious activity such as breathing and heart rate
Meristem Tissue
Plant tissues containing undifferentiated stem cells
Motor Neurone
A neurone that carries nerve impulses from the CNS to the effectors.
Myelin Sheath
A electrically insulating layer that surrounds the axon and increases the speed of nerve impulses
Neurones
Nerve cells adapted to quickly transmit nerve impulses. They are the functional part of the Immune system
Neurotransmitters
Chemicals that are used for communication between neurones and their target cells
Percentile Chart
A chart used to monitor growth or time. Can be compared to expected values helping to identify abnormal patterns.
PET Scan
An imaging technique used to assess the structure and function of the brain through the use of radioactive chemicals. Comparison to a normal brain can highlight unusually active or inactive areas.
Pupil
A hole in the centre of the iris that allows light to enter the eye
Reflex
A rapid and automatic response to a stimulus by the body
Reflex Arc
Stimulus Sensory Receptor Sensory Neurone Relay Neurone Motor Neurone Effector Response
Relay Neurone
A neurone that carries nerve impulses from sensory neurones to motor neurones within the CNS.
Retina
A light sensitive layer at the back of the eye composed of rod and come cells. It converts light into nerve signals sent to the brain
Rod Cells
Cells found in the retina that are sensitive to low light intensity
Sensory Neurone
A neurone that carries nerve impulses from receptors to the CNS
Sensory receptors
A specialised structure that detects a specific type of stimulus
Short-Sightedness
A defect of the eye where distant object appear out of focus due to the convergence of the light rays in front of the retina. This occurs when the eyeball is too long or the lens is too thick and too rounded. It is corrected using a concave lens
Stem cells
Cells that are unspecialised and capable of differentiating into a range of cell types
Synapse
A small gap in between neurones which a nerve impulse is transmitted via neurotransmitters.
Nucleus is made of…
Genetic information made of chromosomes containing DNA.
A Gene
A short section of DNA that codes for a protein and controls a characteristic
How Many Pairs of Chromosomes are in Each Cell?
23 Pairs - 46 Chromosomes
Sex Cells Have…
Half the number of chromosomes
A diploid cell has…
46 Chromosomes
A Haploid Cell Has…
23 Chromosomes
Haploid Cell Examples
Sperm and Egg Cells
Cell Division is for…
Growth and development, replacing damaged cells and a vital part of asexual reproduction.
Mitosis Produces…
2 Identical Diploid Daughter Cells
Nucleus contains…
Chromosomes
Chromosomes Contain…
DNA
Genes are…
A short section of DNA that codes for a protein.
Each chromosome carries many…
Gene’s
Amount of Chromosomes
23 Pairs (Half from Father and Half from Mother)
Sex Cells are also know as…
Gametes
Gametes have…
23 Chromosomes in Total
A diploid is…
23 Pairs of Chromosones
A Haploid is…
23 Chromosomes in Total
Cell Cycle…
Interphase, Prophase, Metaphase, Anaphase, Telophase, Cytokinesis
Interphase
Stage 1
DNA copies itself ready for mitosis.
Prophase
Stage 2
DNA chromosome become more visible and membrane around nucleus disappears.
Metaphase
Stage 3
Chromosomes and their copies are line up in the middle of the cell.
Anaphase
Stage 4
Chromosomes and their copies are pulled to different ends of the cells.
Telophase
Stage 5
New membranes form around the chromosomes at each end of the cell.
Cytokinesis
The cell membrane pinches in and divides the two daughter cells.
Mitosis
A form of cell division that produces two genetically identical cells (with full sets of chromosomes) from one parent cell.
Cancer is caused by…
Small changes in cells that lead to uncontrolled cell division. A group of these cells are called a tumour.
If a Child is in the 95th Percentile for Height it is…
Taller than 95% of children of the same age and shorter than 5% of children of the same age.
Form when an egg and sperm cell fuse to form a zygote.
Can differentiate into any cell in the body.
Can be replicated in lab conditions.
Adult Stem Cells
Found in bone marrow.
Can make many types of cell like red blood cells.
Meristems
Found in plant roots and shoot tips.
Can differentiate into any type of plant.
Can be used to clones plants.
