Topic 1,2: key concepts- cells, microscopes, mitosis, growth, stem cells, nervous system. Flashcards
What is the vacuole?
A bag like structure which holds water and nutrients and helps keep the cell rigid
What is the chloroplast?
Contain green pigment call chlorophyll. Chlorophyll is used in photosynthesis.
What are special about palisade cells?
They have extra chlorophyll to help with photosynthesis
What do ciliates epithelial cells do?
Keep the airways clean by trapping dust and microbes.
Arteries carry blood…
Away from the heart
What does the cell membane do?
Controls what goes on and out of the cell.
What do the mitochondria do?
Where respiration happens. - energy is released from glucose.
What does the cytoplasm do?
provides cell shape and is where reactions take place.
What do ribosomes do?
Where protein synthesis happens, the process in which proteins are made.
What is mitosis?
The process in which cells divide
What is a chromatid?
an arm of a chromosome preparing to divide.
What are the phases of mitosis?
IPMAT interphase prophase metaphase anaphase telophase
What happens in each phase of mitosis?
interphase: when the dna replicates
prophase: The DNA forms chromosomes and the nucleus membrane disappears
Metaphase: spindle fibres form across the cell and the chromosomes line up along the equator
Anaphase: The chromatids get pulled apart to either end of the cell/poles.
Telophase: A nucleus develops around both sets of chromosomes (cytokinesis) the cytoplasm divides into two cells that are genetically identical
What are stem cells?
special cells which can differentiate into many different types of cells and are essential to developing as an embryo.
Where are stem cells found?
In animal embryos and in bone marrow. Normally once an animal is fully developed, the stem cells can only produce the same type of cell that is around them. in plants stem cells remain fully functional throughout their life.
Why are stem cells useful?
Because they can treat many different diseases and illnesses including wounds and genetic diseases.
What do pluripotent and totipotent mean?
pluripotent: can become only a few different cells.
totipotent: can become any different cell.
What is the order of the nervous system?
Receptor>sensory neurone>relay neuron>motor neuron>effector
What happens in the sensory neuron?
It receives an impulse from a receptor and passes it on to the relay neuron in the spinal chord via its axon terminal.
What happens in the relay neuron?
Receives the impulse from the sensory neuron and passes it on to the motor neuron.
What happens in the motor neuron?
The motor neuron receives the impulse from the relay neuron and then stimulates the effector.
What is a synapse?
the junction between neurons such that the nerve impulse is transmitted from a neuron to another neuron or to a muscle cell or gland cell.
How does the synapse pass on the electrical impulse?
1) The impulse travels along the axon terminal in the first neuron.
2) The electrical impulse stimulates the chemical neurotransmitter
3) The chemical neurotransmitter diffuses from the axon terminal to the dendrite.
4) The receptor in the dendrite picks up the neurotransmitter and activates the electrical impulse onto the next neuron.