If a boy exhibits a sex-linked trait that is carried on the x chromosome, what must be true?
a. his mother exhibited that trait.
b. his father exhibited that trait.
c. his father’s mother carried an allele for that trait.
d. his mother carried at least one allele for that trait.

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.

Sea levels are rising due to climate change while increasing numbers of people are moving into coastal areas. to accommodate more people, there has been increased construction of beachfront resorts and condominiums. how is this impacting sea turtle numbers and biodiversity and why? a. the increased human population in coastal areas has meant that more food is available to the turtles (e.g., dropped food, waste from restaurants), which has led to an increase in the numbers and diversity of sea turtles. b. there has been very little change in the numbers and biodiversity of sea turtles because the planet is so vast that they can simply relocate to less crowded beaches. c. this has resulted in a decrease in numbers and diversity of sea turtles because it is restricting available nesting sites, and hence reproduction. d. this has resulted in an increase in numbers and diversity of sea turtles because people are around to protect them from natural predators.

Look at the photo of the leaf. which term best describes this leaf?