Scientific investigations begin by asking questions that can be tested, measured, or both. Which question meets this criterion? What opinions do teenagers have about vaccines?
Do hand sanitizers decrease a person’s risk of a bacterial infection?
Is buying organic food an ethical choice?
How hard is it for people to reduce stress in their lives?

a. autosomal.

explanation:

depends where

on my head

yes

on my legs

yes

on my

arms

yesh

in the year 2850, humans successfully colonized mars. the martian modules that were constructed could hold only a small population of people. it is now a century later, and the population on mars has grown to 600 people. of the current mars population, 45 people express the recessive phenotype for phenylketon- uria (pku) syndrome (pp genotype).

explanation:

blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen-poor blood from the body into the right atrium of the heart. as the ventricle contracts, blood leaves the heart through the pulmonic valve, into the pulmonary artery and to the lungs where it is oxygenated.