A.sleep movements of clover leaflets at dusk
B.initiation of seasonal migration in birds
C.breaking of diapause in the cabbage white butterfly
D.breaking of bud dormancy in oak
E.induction of flowering in biennials such as carrot and swede
F.nocturnal secretion of nectar by moth-pollinated flowers
G.laying down of fat in brown in bears prior to hibernation

a.which of these are under phoyoperiodic control?
b.which are a response to a period of cold
c.which is under endogenous control?

ok.for a. photoperiodism refers to the regulation of seasonal effect by daylength. therefore anything to do with daylength that changes a pattern of animals will be photoperiodic. in my opinion, only B is. this is obviously wrong.
b.diapause is a period of arrested development,this development can only be resumed by a period of low temperature.so C is. also, bud dormancy is the development of buds which remain actively maintained by the abscisic acid, the development only resumes by a period of cold. so D is.
c.endogeous rhythm continues under constant condition if the orgainsm is subject to a constant environment. therefore, endogenous rhythm is not influenced by the external environment.therefore i would choose A and F.

however SOME of my answers are not correct. some of the info is completely bullshit.( 😥 )hopefully, pros can help me sort out.

by the way, how do pros study behaviours of animals, i dont wanna memorise every animal’s behaviour.
cheers