More notes this time for biology, just finsihed these earlier -good luck tomorrow...
Patterns of Behaviour
Innate Behaviour
Innate - genetic - little influence from the environment - varies little within species - doesn’t need to be learnt
Learned - develops from animals interaction and experience from the environment - allows animals to adapt to an environment - not passed on genetically
Taxis & Kinesis
Innate behaviours
Taxis - orientating behaviour- directional - move towards or away from a stimulus
Kinesis - orientating behaviour - non directional - if environment is favourable, speed is decreased rate of turning is increased - allows organism to remain in favourable conditions
Reflex Actions
Reflex escape responses
Rapid, innate, automatic response to a stimulus
e.g. stimulus à receptor à sensory neurone à relay neurone à motor neurone à effectors à organism escapes/moves out of danger
Linking a number of reflexes too produce a more complicated behavioural response e.g. feeding a new born infant
Rooting Reflex - nipple seeking behaviour - as breast touches babies cheek baby turns its head, mouth open until it finds the nipple
Sucking Reflex - when lips touch nipple baby starts sucking
Let Down Reflex - Stimulation of nipple causes oxytocin to be released from the pituitary gland - oxytocin causes smooth muscles in the mammary glands to contract, releasing milk
Modified Reflexes
Learn to control a reflex of the ANS
Gain conscious control of the bladder
Stretch receptors in bladder send impulses along ANS, but also too the brain, motor areas send impulses to second sphincter too contract
Also inhibitory signals sent from CNS too inhibit normal reflex
Learned Behaviour
Habituation - when an animal becomes accustomed to something - e.g. when an animal learns too stop responding to a stimulus
Imprinting - e.g. goslings imprint on their mother - imprinted object used as a parent figure in times of distress - object of sexual desire
Conditioning
Classical - stimulus leads too a response - new stimulus given at same time as original stimulus - repeated many times - animal associates new stimulus with old stimulus - now animal has the same response for both stimulus
e.g. Pavlov with dogs - dogs salivate on sight and smell of food - Pavlov rang a bell every time before he served the food - repeated - after time the dog would salivate on just hearing the bell
Operant Conditioning - trial & reward learning - Skinners rats/box - rat presses leaver - food released (reward) - positive reinforcement - rat is then more likely to do it again, quicker
Similarities between humans e.g. parents give their children money if well behaved
Reproductive Behaviour
Courtship
Courtship is necessary for successful mating
Species Recognition - each species has their own courtship display too attract the opposite sex of the same species - this is important when two of the same species live close together to avoid aggression - aggression is a waste of energy and could possibly cause injury
Pair Bond Formation - synchronise breeding activities - pituitary glands secrete gonadotrophic hormones which stimulate production of sex hormones - oestrogen stimulates ovulation - so she is ready too mate
Sexual Selection - allows female too choose a healthy mate, who is going to be able to look after her and support their offspring
Sign Stimuli & Innate Releaser Mechanisms
Visual sign - usually coloured - triggers an innate reflex - communication between species - multiple sign stimuli can be strung together in courtship behaviour patterns
Territorial Behaviour
Reduces fighting and aggression between species
Advantageous because - reduced energy output - reduced risk - maintenance of a food source - defence of a nest site
Menstrual Cycle
Pituitary Hormones - FSH - follicle stimulating hormone - LH - lutenising hormone
Ovarian Hormones - Oestrogen - repair uterine endometrium - Progesterone - maintain uterine endometrium
The menstrual cycle uses negative feed back
Sequence - FSH stimulates growth of follicle - developing follicle produces oestrogen - rising oestrogen inhibits FSH production and promotes production of LH - LH stimulates follicle development into conversion of corpus luteum - rising oestrogen stimulates FSH production - surge in FSH & LH cause ovulation - LH stimulates progesterone production - progesterone inhibits FSH & LH
Contraception
Reliable methods - oral pill/ barrier contraceptive/ implant/ vasectomy/ IUD
Oestrogen/ Progestin Pill - oestrogen inhibits FSH - progestin inhibits LH which reduces chance of ovulation - also thickens cervical mucus so acts as a barrier to sperm
Infertility
Use extracted/ synthesised hormones e.g. clomiphene which stimulate hormone production
In vitro fertilisation - use fertility drugs too stimulate ovulation - collect mature eggs and incubate with sperm - insert embryo’s into the uterus
Pregnancy
Conception
Capacitation - ejaculation - sperm has a protective membrane of protein and lipoproteins - enzymes must remove the coating before fertilisation occurs
Acrosome Reaction - fertilisation occurs in the oviduct - contact between granulosa an occyte trigger the acrosome reaction - enzymes released from acrosome - enzymes create a gap too the zona pellucida - sperm binds too a ZP3 receptor protein on the zona pellucida - this forms a slit into the oocyte - the sperm enters the oocyte - its back fuses with the oocyte membrane - the tail keeps moving causing the oocyte too rotate inside the zona pellucida - enzymes cause cortical granules too thicken - ZP3 receptors destroyed
Cortical Reaction - only one sperm fertilises the oocyte - zona pellucida forms a barrier enzymes cause cortical granules too thicken - ZP3 receptors destroyed
Hormones In Pregnancy
Once an embryo is implanted on the endometrium it releases HCG
HCG - Human Chorionic Gonadotrophin
Acts on the corpus luteum so it continues too secrete progesterone - maintaining the endometrium - also inhibits FSH so no follicles develop
Pregnancy Test
Conformation of pregnancy by detection of HCG or higher levels of progesterone
HCG/Progesterone specific shapes, bind too complementary structures - binds too a tracer - makes a colour
Placenta
Supplies substances e.g. glucose, amino acids for growth
Removes nitrogenous waste/CO2
Placenta - blood never mixes - allows exchange of substances - hormone production
Many chorionic villi and microvilli to increases surface area for exchange of substances, large conc gradients due too counter current multiplier effect - foetal blood has a higher affinity for oxygen - active transport - pinocytosis of anti bodies
Physiological Changes
Body Mass - foetus/placenta - myo/endometrium - blood mass/haemoglobin - plasma - body fat
Cardiovascular - rich blood supply - larger heart - increase in plasma and blood cell mass - transport more substances - increased blood flow too maintain conc gradients for effective diffusion
Kidney Function - Increased blood flow through kidneys - larger kidneys - increased waste products - more conc urine due too amino acid metabolism in foetus
