Pencil lead is dull and brittle. That's why it breaks off when you drage it across paper. Therefore, pencil lead is made out of an element that is a ?
- non-metal
- metal
- metalloids
- metalloid

Animal bodies (and even plant bodies for that matter) are complex enough that life couldn't exist without enzymes. enzymes are usually large, complex biological catalysts that are expensive to make. enzymes speed up the rate of chemical reactions without being used up during the reaction (they can be reused many times). they are highly specific in the reactions they regulate. knowing what enzymes are and how they function, why does this explain why complex life forms could not exist if there were no enzymes.

The negative impacts of nonnative species generally outweigh the positive impacts

Anormal appearing couple is found to be heterozygous recessive for albinism both have the genotype aa the gene responsible for albinism is recessive to the normal pigment-producing gene what are the changes of their children being albino