Why were the scientists concerned about the glue used to reattach the barn swallows’ tails?
a)they thought its smell might keep females away.
b) they were worried it might hurt the birds.
c) they did not know if it would hold the tails in place very long.
d) they were afraid it could not be removed.

Which statement best describes a keystone species? o a. it has littlelmenetic variation. it has an extremely high population. 0 b. 0 c. it remains unaffected by all environmental changes. od. it has a strong influence on the ecosystem. 0 e. it's the first species to populate a new ecosystem.

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.

“in 1492 columbus sailed the ocean blue” is an example of: a)explicit memory b) procedural memory c) semantic memory d)episodic memory