Wolves were reintroduced to Yellowstone National Park in 1995. This keystone species restored the park’s ecosystem. What is the ecological value of a keystone species?

The intervention of extraterrestrials has been used to explain the bermuda triangle, a region of the atlantic ocean where ships and planes are frequently lost, leaving no evidence behind. how would this explanation best be characterized?

Matched chromosomes carrying information about the same characteristics in the organism are called

During crossing-over, a. genetic material is exchanged between nonsister chromatids, resulting in new combinations of alleles. b. nonsister chromatids from each homologous chromosome of a tetrad are exchanged, resulting in new combinations of alleles. c. one homologous chromosome of a tetrad is exchanged with another tetrad, resulting in new combinations of alleles. d. sister chromatids from each homologous chromosome of a tetrad are exchanged, resulting in new combinations of alleles. e. genetic material is exchanged between sister chromatids, resulting in new combinations of alleles.