A(n) keeps blood from flowing backwards

Give the biological term for: structures that display characteristics of living organisms only within living cells

Two male mice, which we will call male a and male b, are both phenotypically normal. male a was from a litter that contained half phenotypically normal mice and half dwarf mice. the mother of male a was known to be homozygous for the normal igf2 allele. male b was from a litter of eight mice that were all phenotypically normal. the parents of male b were a phenotypically normal male and a dwarf female. male a and male b were put into a cage with two female mice that we will call female a and female b. female a is a dwarf and female b is phenotypically normal. the parents of these two females were unknown, although it was known that they were from the same litter. the mice were allowed to mate with each other, and the following data were obtained: female a gave birth to three dwarf babies and four normal babies. female b gave birth to four normal babies and two dwarf babies. which male(s)mated with female a and female b? male a with both females male a with female b, and male b with female a male a with female a, and male b with female b could not be determined male b with both females

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.