You could talk about how plants supply food for animals.
E.g cacti provide food and water for desert animals and rodents.
small rodents provide food for larger animals and snakes.
some animals will clean larger animals in a mutualistic relationship.
it separates the inside of the cell from the environment outside and it controls substances moving in and out of the cell (selectively permeable)
A physical change occur when objects or substances undergo a change that does not change in which the composition of a substance changes or one or more substances combine or break up from new substances.
I can answer the third one:
Photosynthesis takes place in two stages<span>: light-dependent reactions and the Calvin cycle (light-independent reactions).</span>
Arrector Pili<span> Muscle - This is a tiny muscle that attaches to the base of a hair follicle at one end and to dermal tissue on the other end. In order to generate heat when the body is cold, the </span>arrector pili<span> muscles contract all at once, causing the hair to "stand up straight" on the skin.
Hope this helped, credits go too google.</span>
