Flashcards
Biology Unit 2 Flashcards
Cards in this deck (23)
- 1Describe the role of the central nervous system in humans-Accepts information
-Processes information
-Responds to information - 2Describe the functions of the cerebrumcontrols all higher activities e.g. memory, emotions, processes information and intelligence
- 3Describe the functions of the cerebellumcontrols balance and co-ordination of muscles, involved in precise, accurate movement
- 4Describe the role of the MedullaControls activities that animal isn't conscious of - breathing, digestion, heart rate etc.
- 5Describe the role of sensory neurons in the nervous systemtransmit messages from sense receptors (e.g. nose, eye) to the brain or spinal cord(CNS)
Receptors to relay neurons - 6Describe the role of relay neurons in the nervous systemconnects a sensory neuron to a motor neuron - passes impulse from sensory to motor neuron
- 7Describe the function of the motor neuron in the nervous systemcarry information towards an effector which may be a muscle or a gland
- 8Describe what happens when electric impulse signal arrives at a synapsewhen an electrical impulse arrives at a synapse neurotransmitter molecules are releases from synaptic vesicles. the neurotransmitters diffuse across the synaptic cleft, triggering receptors on receiving neuron to release an electrical impulse
- 9Describe the flow of information along a reflex arcfirstly stimulus is detected by receptors and electrical impulses are passed along the sensory neuron. the signal is then passed from sensory neuron to the relay neuron where it is then passed onto the motor neuron. the signal then reaches the muscle/gland and the muscle/gland responds
- 10Explain how the action of hormones is specific. (2 marks)target tissues have cells with receptor proteins - the hormone only affects receptors on it's target cells
-each hormone has a function not carried out by any other - 11describe the role of the pancreas in the control of blood sugar. (2 marks)-produces insulin which causes excess blood glucose to be stored
- produces glucagon, which causes the release of glucose from the store - 12Describe the role of the liver in the control of blood-stores excess glucose as glycogen
-release glucose from glycogen - 13describe the control of blood glucose concentration in humans. (3 marks)- raised glucose triggers insulin release by pancreas
-insulin causes liver to convert to glucose to glycogen and store it
when glucose levels fall glucagon released by pancreas
-glucagon cause liver to convert glycogen back into glucose and release it back into the bloodstream
-(glucagon converts glycogen to glucose)
(Any 3 of the above is sufficient) - 14Describe the two types of diabetes. (3 marks)- type 1 appears in childhood usually
- type 1 cause by lack of insulin
- type 2 often appears in overweight individuals
- type 2 caused by liver receptors not responding to insulin - 15What is the meaning of specialised in relation to cells?has certain physical and structural characteristic which allow the cell to carry out a specific function - structure is suited to the function
- 16what is the general function of stem cells?to produce more cells for growth and repair - to replace cells that are damaged or lost - divide to produce a supply of cells which can then specialise
- 17Describe what happens to a stem cell that results in the production of a red blood cell that results in the production of red blood cells in humans-cell division -stem cells divides
-loses nucleus
-produces haemoglobin
-develops biconcave shape - 18describe the differences and similarities between adult and embryonic stem cellssimilarity - both can divide, both are un-specialised
differences - embryonic stem cells can become any cell, adult limited to only a few types of cell - 19describe the ethical issues surrounding research into human embryonic stem cells-moral principle to improve medicine
-moral principle to respect human life
- these two principles cannot both be respected in embryonic stem cell research - 20give the meaning of haploida cell with one set of chromosomes - always sex cells(gametes)
- 21give the meaning of diploida cell which contains two sets of chromosomes
- 22describe the differences between a sperm cell and an ovumsperm cells are tiny and have a tail for swimming
ova are large and have a food supply to feed early embryo - 23describe how fertilisation is achieved in a flowering plant-male pollen carried from anther to the stigma by wind or insects
-pollen grows pollen tube through style to ovary
-pollen nucleus fuses with female ovule nucleus
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- Description
- Flashcards for National 5 Biology Course - Unit 2 Multicellular organisms. Sorry if all topics aren't included yet, I will add them as I progress through unit 2 in class. These questions are taken from extended response questions completed in class - all answers are model answers from my teacher. Hope this helps
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- themoonisdown
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