The integumentary system, which is the largest organ system of the human body, is made up of skin, hair, nails and glands. The respiratory system is composed of the respiratory tract and the lungs. How do the integumentary and respiratory systems work together to protect the human body?

A. The two systems allow for the storage of nutrients to fuel the body at a later time.

B. The two systems deliver signals between the outside environment and the brain.

C. The hair and mucus that line the respiratory tract prevent foreign particles from entering the body.

D. The immune cells send electrical signals through the skin to the brain.

Environmental differences within ecosystems are generally caused by

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?

Radiometric dating is used to tell the absolute age of materials by studying the decay rate of radioactive isotopes. the decay rates of isotopes are constant and are expressed as .