What is the function of the scrotum 1 protection of the test

What is the function of the scrotum?
1- protection of the testis
2- thermoregulation of the testis
3- production of seminal fluid
4- both 1& 2
5- both 1 & 3
heterosis is a genetic effect that occurs following:
1- brother x sister matings
2- genetic selection
3- line breeding
4- crossing different genetic lines

chromosome number in animals determines by
1- size of the adult animal
2- size of the egg cell from the female
3- amount of dna in each cell
4- all of the above
5 none of the above


(answer with numbers no needs to wite reasons)

Solution

What is the function of the scrotum? The correct answer is: 4.both 1 and 2

heterosis is a genetic effect that occurs following: The correct answer is:4.crossing different genetic lines

chromosome number in animals determines by: The correct answer is : 5.none of the above