Which events occur when a star is forming? check all that apply.
the outer layer of the star expands.
gravity pulls gas and dust together.
a protostar forms as mass increases.
a black hole forms as the core collapses.
nuclear fusion begins under high pressure.

What are two reasons for why a species might disappear from the fossil record?

Awire-hair terrier and a smooth-hair terrier are mated. the offspring produced are 6 wire-hair puppies and 2 smooth-hair puppies. a. what pattern of inheritance best describes this situation? b. what is the genotype(s) of the wire-haired puppies? of the smooth-haired puppies? c. what would be the expected genotype and phenotype ratios of a mating between 2 wire-haired terriers that are heterozygous?

Dna replication occurs in preparation for