The Punnett square for a sex-linked trait is shown. Xr is the recessive allele. Based on the Punnett square, which statement is true? Xr X
X XrX XX
Y XrY XY
A.
Female offspring have a 50 percent chance of expressing the recessive trait.
B.
Both male offspring will express the recessive trait.
C.
Both female offspring will express the recessive trait.
D.
There’s a 50 percent chance the male offspring will express the recessive trait.

Charles darwin published his theory of evolution in 1859. in what way foes modern evolutionary theory differ from the theory as proposed by darwin? a) darwin inferred that individuals can evolve, but modern generic science has shown that this is not true. b)darwin inferred that individuals do not evolve, but modern genetic science has shown that this is not true. c)modern science has disproved most of darwin's original theory of evolution, because darwin knew nothing about generations and their role in heredity. d)generic studies have shown that gene expression and other factors operate along with natural selection, but most of darwin's theory has been supported by modern science.

Which ideas did your answer contain? check all that apply. no food for organisms no oxygen in the atmosphere no trees or flowering plants no products based on trees or plants (building materials, medicines, fuels, fibers) no fossil fuels

The leopard frog and the pickerel frog are two closely related species. in areas where their ranges overlap, the frogs will remain separate species if they