What is made by white blood cells to help fight off infection?
Where do food chains begin?
What is the process of breaking down food called?
What kind of plant stem is soft and green?
What fluid-filled sac surrounds the human embryo?
What is the outer skeleton of organisms such as spiders and insects called?
What openings in a leaf allow gas exchange?
What does the substance melanin control?
Color Of The Skin
What is the waxy covering on plant leaves?
Where does the zygote of a gymnosperm develop?
In The Ovule
A person who specializes in the study of plants is called what?
What is the sticky part of the pistil called?
What type of reproduction uses only one parent cell?
What happens to your skin's blood vessels as you exercise?
Where are the female sex cells of a flower located?
What is a full set of bones called?
What is another name for the voice box?
What science word means "to group"?