How can you make number one disappear by adding something to it?

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

What Word am I Looking For ?

Astrology starts with the alphabet A, Biology starts with B, Psychology with P and Limnology with L.

Can you find an "ology" that begins with a P?

John is the son of Jacob.
So,
Jacob is the_____of John's father?

Can you find the six hidden animals in the picture below?

A family is trapped in a jungle. There is a bridge which can lead them to safety. But at one time, the bridge can only allow two people to pass through. Also, all of them are afraid of the dark and thus, they can't go alone.

Father takes 1 minute to cross, the mother takes 2 minutes, the son takes 4 and the daughter takes 5 minutes. While crossing the time taken will be according to the slower one. How can they all reach the other side in the minimum possible time?

I have a hole in my back and legs I lack.
I live where I can’t breathe and I eat without teeth.
What am I?

I am a white box having no key or lid.
Yet there is a golden treasure inside it.

What Am I?

Jack have ten pairs of black socks, eight pairs of white socks and seven pairs of green socks. Everything is mixed in a draw. As there is no light he were not able to identify the colour of the socks. How many of the socks did he want to take to match one pair

You walk into a room that contains a match, a kerosene lamp, a candle and a fireplace. What would you light first?