Why is heartwood darker in color than sapwood?
a. heartwood is closer to the center of the stem; sapwood is away from the center of the stem
b. heartwood does not conduct water; sapwood is active in fluid transport
c. heartwood contains xylem tissue; sapwood contains phloem tissue

Gregor mendel is best known for his work with pea plants and for uncover many of the mysteries of genetics. one of his major findings stated that there were specific, physical units of inheritance that are transmitted during reproduction. what is the the name given to these units of inheritance which can be found on chromosomes? a) centromeres b) cytoplasm c) genes d) nucleotides

Which kind of mutation has occurred when the codon for an amino acid is changed to a stop codon? a. a silent mutation b. a missense mutation c. a frameshift mutation d. a nonsense mutation

Which rate indicates the number of children that would be born per women if she were to live to the end of her child-bearing years