If all Goats are Sheep and all Sheep are Deers, are all Deers Goats ?

I am looking for a word that change both gender and number when i add the letter 'S'.

What Word am I Looking For ?

I am a type of food that is often found in the fridge and can be white in colour. What I am?
Hint 1: I am a dairy product.
Hint 2: You can spread me on the bread.

Name one eight-letter word with 'kst' in the middle, 'in' the beginning, 'and' at the end.?

You Throw The Outside, Cook The Inside
Eat The Outside, Throw The Inside.

What Is It?

He does not have any heart but still, He manages to live.
If you kill him, you will eventually die but yet you kill him.
He cannot run, who is He?

I have a sore throat and a severe headache. I have four tablets with me that are identical to each other and they do not have any cover on them. There is no way I can identify which tablet serves what purpose. The only thing that I know is that two of these four tablets are for the throat and the remaining two are for the headache. To treat my condition, I must take 1 of each. What will I do now?

My cousin lives in one story house in Antarctica. His house is made the of-of sandstone. what is the color of stairs?

There is a basket full of hats. Three are white and two are black. Three men, Tom, Tim, and Jim, each take a hat out of the basket and put it on their heads without seeing the hat they selected or the hats the other men selected. The men arrange themselves so Tom can see Tim and Jim’s hats, Tim can see Jim’s hat, and Jim can’t see anyone’s hat. Tom is asked what color his hat is and he says he doesn’t know. Tim is asked the same question, and he also doesn’t know. Finally, Jim is asked the question, and he does know. What colour is his hat?

What Adam and Eve do not have but the rest of the people have?