Research has shown that a person's height is about 81 percent heritable, whereas his or her body mass index (BMI) is about 59 percent heritable. Which of the following is the most accurate interpretation of these findings?
a. The variability we see in a population's height is more influenced by genetic factors than the variability we see in the population's weight.
b. Environmental factors account for only 19 percent of a person's height and 41 percent of a person's BMI.
c. We cannot make any conclusions about genetic contributions to either height or weight.
d. Knowing the relative genetic contributions to traits such as height or weight does not allow us to compare these two unrelated characteristics of people.
Question 2
One major difference between striated and smooth muscles is that
a. smooth muscles move the voluntary system and striated muscles move automatic systems.
b. striated muscles are responsible for fast twitch and smooth muscles are responsible for slow twitch.
c. striated muscles move mostly voluntary systems while smooth muscles move involuntary, automatic systems.
d. smooth muscles are made up of myofibrils and striated muscle is made up of only sarcomeres.
Gas exchange across body surfaces.
(A) The structure of a neuron, showing the dendrites, nerve cell body, and axon. (B) Photomicrograph
Primary pulse points of the body.
Good body mechanics for lifting heavy objects.
Systems of the Human Body
Percentage of youth age 15 to 19 years with at-risk levels of body composition & fitness