if the adjacent tryptophan codons in the trp operon leader sequence are mutated to alanine codons, what is the predicted effect on trp operon regulation?

Elephants in the savanna regions of africa dig holes in dried up river beds to reach water lying just below the surface. these holes provide drinking water for other animals as well. so, without the elephants, many animals might otherwise die from lack of water during the dry season. the location in which the elephants live is an example of a/n and the role they play in creating water holes is an example of a a) ecosystem; habitat b) community; niche c) habitat; niche d) niche; habitat

What makes a dominant allele different from a recessive allele

Is there any solid scientific evidence that humans have been cloned?