Pheromones

Question 1

silk pheromones

Answer 1

bombykol, release by female to attract males
males detect pheromone from the antenna which fires an action potential upon exposure of bombykol diluted in 10^7 air molecules

Question 2

pheromones for marking/territorial behaviour

Answer 2

in dogs, these pheromones are present in the urine, which they deposit on landmarks where they claimed territory

Question 3

pheromones for dominance hierarchy

Answer 3

used in wolves - have sweat glands all over their body: tails, genitalia, skin and between toes
pheromones secreted in those glands will identify the wolve
a dominant wolf will rub its body against subordinate wolves to mark them as being a member of the pack

Question 4

aggregation pheromone

Answer 4

observed in desert locust 
function in defence against predators, mate selection and overcoming host resistance by mass attack

Question 5

primer pheromones

Answer 5

observed in termites in which it trigger a change in developmental events

Question 6

Dauer pheromones

Answer 6

c.elegans
in response to high population density or low food supply, c.elegans enters an alternative larval stage (they become dormant)
they sense the population density by the release of dauer pheromones

Question 7

alarm pheromones

Answer 7

species release alarm pheromones in response to predator that can trigger flight or aggression (in ants and bees)
plants also release pheromones tannins to make it less appetising when sensing herbivores near by

Question 8

trail pheromones

Answer 8

common in social insect - non-volatile hydrocarbons

they release trail pheromones as they track for food and it serves as a guide

Question 9

name three pheromone effects in mammals

Answer 9

Coolidge effect: re-mating with new potential mate

Vanderbergh effect: female rodent pups undergo puberty faster in presence of male that absence. Female pups also undergo puberty faster when raised in isolation

bruce effect: spontaneous termination of pregnancy followed by re-mating with new male. signalling through the urine of the novel male mice

Question 10

VNO responds to

Answer 10

non-volatile chemical cues

Question 11

define pheromones

Answer 11

chemical signal which is used to convey information between members of the same species

Question 12

individuals pheromones

Answer 12

MHC
the genes codes for special protein markers which mark the cell as endogenous or foreign
- advantageous for mother to select mates with different MHC protein
- protein fragment produced by the MHC is secreted through the bodily fluid giving a unique protein fragment odour associated with the original MHC

Question 13

detection of human pheromones

Answer 13

the accessory olfactory bulb thought to play a role in pheromone detection
because the vno is found non-functional in humans

Question 14

name two odourants present in human sweat which triggers different responses in female and male

Answer 14

AND and EST
AND = activity at ventromedial hypothalamus associated with copulatory function
EST= dorsomedial and thalamic nucleus associated with regulation of penile erections