MATERIALS AND METHODS1. Dependent Variable2. Independent Variable3. Controlled Variables4. What instrument was used to measure cardiac volumes?5. Does the instrument that was used to measure cardiac volume use X-rays? Explain.

answer; the above statement is (true);

•there must be variation for the particular trait within a population.

•the variation must be inheritable (that is, it must be capable of being passed on from the parents to their offspring).

•individuals with one version of the trait must produce more offspring than those with a different version of the trait.good

explanation: