Answer:
Positive feedback system increases temperature of the earth surface which is good in a number of ways.
Explanation: For example, due to increase in the temperature of earth surface, melting of ice occurs in the mountainous area of the world. This stored form of water is changed into liquid form and flows down through streams and used by plants and animals. But more increase in temperature causes rise of sea level which is not good for areas near the sea.
Answer:
oxygen enters blood cells by 'diffusion'
Digestion begins in the mouth. Saliva contains enzymes which begin to break down food. The mouth also uses the teeth and jaw to mechanically break down food.
Most adult placental mammals have no remaining trace of the cloaca. Being placental animals, humans only have an embryonic cloaca, which is split up into separate tracts during the development of the urinary and reproductive organs.
It would hard to live and you would be sick no protection I hope this helps
