CB2 Flashcards
Prophase
Spindle fibres form in the cell and the nuclear membrane starts to disappear.
Metaphase
Chromosomes line up in the middle of the cell.
1st part of Mitosis
Anaphase
The chromosomes are pulled apart by spindle fibres.
2nd part of Mitosis
Telophase
The single chromosomes arrive at opposite ends of the cell and the membranes around each nucleus start to form again.
3rd part of Mitosis
Cytokinesis
The cytoplasm of the cell separates and the cell membrane divides the cell into two daughter cells.
Interphase
The DNA in the cell is copied, making X-shapes, each containing a chromosome and its copy, beginning the next cell division cycle.
Sensory neurones
The neurones that carry information as electrical impulses from the receptors to the CNS.
Motor neurones
The neurones that carry electrical impulses from the CNS to effectors.
Effectors
All your muscles and glands, which respond to nervous impulses.
Receptors
The cells that detect stimuli
Reflexes
Rapid, automatic responses to certain stimuli that DON’T involve the conscious part of the brain.
Prevents injuries
Adaptations of the sperm cell
Long tail and streamlined head to help it swim
Lots of mitochondria in the cell to provide it with energy
Carries enzymes to digest through egg cell membrane
Adaptations of the nerve cell
Long, to cover more distance
Branched connections at their ends to connect to other nerve cells and form a network throughout the body.
Adaptations of the female egg cells
Lots of cytoplasm as food for energy making it very large.
Adaptations of the muscle cell
Long, so they have space to contract
Lots of mitochondria to generate energy needed for contraction
Adaptations of the root hair cell
On the surface of plant roots, which grow into long “hairs” that stick out into the soil.
Big surface area for absorbing water and mineral ions from the soil.
Adaptations of phloem and xylem cells
Long and joined end to end to form xylem and phloem tubes
Xylem cells are hollow in the centre
Phloem cells have very few sub cellular structures, so that water can flow through them.
Function of a sperm cell
Specialised for reproduction to get the male DNA to the female DNA
Function of a nerve cell
To carry electrical signals from one part of the body to another.
Function of the muscle cell
To contract quickly
Function of the root hair cell
Specialised for absorbing water and minerals.
Function of phloem and xylem cells
Transport food and water around plants in xylem and phloem tubes.
The Central Nervous System is made up of…
Brain
Spinal Cord
Nerves
Sense Organs
3 stages that plants go through as they grow
Cell division
Cell elongation
Cell differentiation
Define diploid
Containing 2 sets of chromosomes, one from each parent
Define haploid
Having a single set of unpaired chromosomes
Define asexual reproduction
Offspring from single organism, same DNA, clones
Stem cells are…
Cells that haven’t differentiated yet, and can go on to become a number of different types of cells.
What is a specialised cell?
Where an unspecialised cell turns into a very specific cell with a very specific function and specific adaptations.
Mitosis is…
A type of cell division where new genetically identical cells are created.
Embryonic stem cells are…
The unspecialised cells of an early-stage embryo
Adult stem cells are…
Stem cells that can only produce the type of specialised cells in the tissue around them.
How do you calculate the percentage change in mass?
Final value - starting value
——————————— x 100%
Starting value
The myelin sheath is…
A fatty sheath around the nerve that insulated the nerves and allows impulses to travel faster.
What is the function of the dendrites?
They receive impulses from receptor cells.
What is the function of an axon terminal?
They pass impulses to other neurones.
A stimulus is…
Anything your body is sensitive to, including changes in your body and your surroundings.
The pathway of a nerve impulse
Stimulus Detected at receptor cells Passed along sensory neurone Impulse travels to CNS Impulse passed along motor neurone Effector receives impulse Response
