A Level Biology synoptic essayWatch this thread
I know what sort of structure to write them in but I don't particularly know how to start them off. One of them is to talk about the importance of receptors in living organisms which I'm struggling with the most. Can anyone help meee?
First make a general statement about what they are e.g. made of glycoprotein/glycolipid and that certain chemicals with a complementary structure bind to them; also that they are specific
Then use the tactics above:
I shall help you start off, yeah? [REMEMBER THE Q says "IMPORTANCE" so ensure you give the examiner "his/her own medicine" so to speak i.e. keep repeating the word "importance"!
Eyes: vision enabled by photoreceptors [rods + cones] transducing light energy into nerve impulses [electrical energy] -----> importance: predators can see prey for nutrition [vultures have the highest concentration of cones per unit area of macula [central part of retina]; prey can see e.g. lion and can run like hell = important for survival; monkeys can jump from branch to branch with precision: importance nutrition once again e.g. eat bananas or nuts.
Ears: Hair cells in cochlea [audioreceptors] enables hearing: cat can hear a hungry dog approaching - importance: survival.
Mouth: Taste buds are receptors that can detect chemical differences Importance: nutrition + recognition of toxins as they are bitter usually - importance: survival.
Nose: olfactory receptors etc etc
Skin: touch/pressure/temp/pain receptors: google Pacinian corpuscles; Meissner bodies; free nerve endings, IMPORTANCE: avoidance of danger ----> survival; etc.
C. NERVOUS SYSTEM:
Receptors for neurotransmitters: Importance: reflex arc [classical e.g. of hand pulled away from fire; homeostasis important for allowing internal environment ideal for biochemical processes e.g. nervous control of hunger/thirst; importance: prevent dehydration or starvation OR opposite [obesity].
Receptors at neuromuscular junction [for ACh] allow movement: importance: escape from predators by using leg muscles + running to catch prey; in humans, movement is highly dextrous so we make gadgets/machines/ and myriads of other items using our hand/thumb muscles for movement; important for progress e.g. aviation/cooking [nutrition]/farming permit survival/nutrition/transport.
Carotid sinus: baroreceptors ----> importance = control of blood pressure.
Carotid body: chemoreceptors; importance: control of breathing/O2 levels in blood [pO2 = partial pressure of oxygen].
Then work through chest heart, lungs; paravertebral sympathetic chain, etc.
Abdomen e.g. digestion; kidneys:, then genitals [+ breasts] e.g. secretion of testosterone [glands are stimulated to secrete their products by action of neurotransmitters on receptors of autonomic system neurones.
This should get you going: REMEMBER WHAT MATTERS IS MARK, MARK, MARK just like in hockey [best sport!], it's goal, goal, goal that counts!
good luck & be safe!