One species benefits from the
interaction, and the other species is neither helped
nor harmed.
•Competition
•Predation
•Mutualism
•Commensalism
•Parasitism

Example: Egrets rely on cows to stir up dirt and
bring food to the surface, but cows do not benefit.

What did hunter gathers do to alter the environment?

Which statement best describes the relationship between an allele and a gene? question 1 a. an allele is a variation of a gene that can be expressed as a phenotype. b. an allele is the part of a gene that attaches to messenger rna molecules. c. an allele is a segment of a dna molecule that controls replication of a gene.

Which set of characteristics best describes sedimentary rock? a) largest type of rock, made of organic matter, hardest type of rock b) often contains layers, forms near sources of water, contains fossils c) least abundant type of rock, made of other rocks, made mostly of minerals d) most abundant type in earth's crust, made of magma/lava, contains no fossils