The main function of the respiratory system is to do what?
a. circulate nutrient rich blood to the body
b. to absorb nutrients into the body
c. to exchange gasses between the blood and the environment.
d. to relay information to the body for life support

The image shows embryos of three vertebrate classes

Suppose you have monohybrid pea plants in your garden and find that they produce round seed to wrinkled seeds in the ratio of 3: 1. if the allele are designated (r & r) receptively. what is the probable genotypes of the round seeds which produced f 1 ? rr & rr rr only rr & rr rr only rr only

When you run, you begin to breathe heavier and faster. your heart beats more quickly, bringing more oxygen to your cells. which organ systems are working together here?