The aristidoideae subfamily of grasses inhabits arid regions and respire using the c4 photosynthetic pathway. a related grass, axonopus compressus, grows in moist, shaded environments and photosynthesizes using the more common c3 photosynthetic pathway. what is a possible explanation for the difference in respiration? (2 points) question 14 options: 1) the grasses coevolved different respiratory mechanisms of the same species in different environments. 2) the grasses evolved as a result of biotic stresses. 3) the grasses evolved different respiratory methods to adapt to the differences in water availability of their environments. 4) the grasses evolved similar respiratory methods due to their common cellular structures.

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.