The heart is an organ because it a. maintains homeostasis.
b. is made up of different kinds of tissues.
c. contains blood.
d. contains muscle.

Based on anatomical similarities, to which modern animal is dr. digger’s creature most closely related?

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?

Darwin’s hypothesis about how life changes over time is now called?