Annual rings in woody stems are caused by an increase in rings of the
a. secondary phloem.
b. secondary xylem.
c. primary xylem.
d. primary phloem.

Apopulation of black bears depends on salmon from a stream for food. if a drought causes the stream to run dry one year, how will this likely impact the black bear population?

Pentane with molecular formula c5h12, exists in three isomeric forms. one shows linear carbon chains, another has one -ch3 groups present on the third carbon atom, and the third has two -ch3 groups present on the second carbon atom. what types of isomers are these? a. geometric isomers b. structural isomers c. halotropic isomers

Plz quick a natural resource that is replaceable through a cycle in nature or sustainable practice is called a? the subject is science