Acetylcholine binds to a GPCR on heart muscle, making the heart beat more slowly. The activated receptor stimulates a G protein, which opens a K channel in the plasma membrane. Which of the following would enhance this effect of the acetylcholine

(a) addition of a high concentration of a non-hydrolyzable analog of GTP

(b) addition of a drug that prevents the α subunit from exchanging GDP for GTP

(c) mutations in the acetylcholine receptor that weaken the interaction between the receptor and acetylcholine

(d) mutations in the acetylcholine receptor that weaken the interaction between the receptor and the G protein

Coat color in cats is determined by genes at several different loci. at one locus on the x chromosome, one allele (x ) encodes black fur and another allele (xo) encodes orange fur. females can be black (x x ), orange (xoxo), or a mixture of orange and black called tortoiseshell (x xo). males are either black (x y) or orange (xoy). bill has a female tortoiseshell cat named patches. one night, patches escapes from bill\'s house, spends the night out, and mates with a stray male. patches later gives birth to the following kittens: one orange male, one black male, two tortoiseshell females, and one orange female. what are the genotypes of patches, the stray male, and the kittens?

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

Explain how the number of similarities between the embryos from early stage to late stage is used as evidence of a common ancestry