Of which era was the cretaceous period?

In a hypothetical breed of dogs, coat color is controlled by two genes. there are six different coat colors in this breed: black, brown, cream, gray, silver, and tan. consider the following crosses. cross 1: black females from a lineage of all black dogs are crossed with brown males from a lineage of all brown dogs. f1 males and females are all black. when f1 are intercrossed, f2 males and females are black or brown. cross 2: black females from a lineage of all black dogs are crossed with tan males from a lineage where all males are tan and all females are cream. f1 males are black, f1 females are gray. when f1 are intercrossed, f2 males and females are black, brown, gray, or tan. cross 3: silver females from a lineage where all females are silver and all males are gray are crossed with brown males from a lineage of all brown dogs. f1 males and females are all gray. when f1 are intercrossed, f2 males are black, brown, gray, or tan, f2 females are cream, gray, silver, or tan. select the correct statements regarding the mode of inheritance of the coat color genes. a) both genes are x-linked. b) both genes are autosomal. c) one of the genes modifies the expression of the other gene. d) each gene has an additive effect on the intensity of coat color. e) each gene independently specifies three colors. f) one of the genes is autosomal, and the other is x-linked.

When listening the levels of orginization in orginisims from the smallest to most complex , which level is just below organs in complexity

Cladistics is a way of classifying organisms by examining the characteristics of their ancestors and descendants and depicting the relationships in a cladogram. which of the following best describes a challenge in classifying organisms this way? a. there are millions of species on earth, and a cladogram is not a practical means for classifying all of them. b. it is impossible to tell which organisms are most closely related to each other using a cladogram. c. cladograms are detail-oriented and do not provide a useful understanding of evolutionary relationships. d. there is a limited number of ways to organize the information, so most cladograms end up looking very similar.