MULTIPLE CHOICE In the space provided, write the letter of the term or phrase that best completes
each statement or best answers each question.
__6. Organisms that live in estuaries must adapt to changes in
a. temperature and precipitation,
b. sunlight and nutrients.
C. oxygen and pollutants.
d. water level and salinity.
7. Why doesn't photosynthesis occur in deep ocean water?
a. The water temperature is too cold.
b. There is no sunlight.
c. There are not enough nutrients.
d. The salinity level of the water is too high.
8. In estuaries, fresh water and salt water mix, forming a(n)
a. algal bloom.
C. coastal boundary.
b. habitat for shellfish.
d. nutrient trap.
9. Most of the nutrients in an arctic ecosystem come from
a. melting ice.
c. sunlight
b. the ocean.
d. lakes.
10. The majority of marine organisms are found in
a. deep ocean waters.
b. shallow, coastal waters.
c. hydrothermal vents.
d. salt marshes.

Mouse liver cells were homogenized and the homogenate subjected to equilibrium density-gradient centrifugation with sucrose gradients. fractions obtained from these gradients were assayed for marker molecules (i.e., molecules that are limited to specific organelles). the results of these assays are shown in the figure. the marker molecules have the following functions: cytochrome oxidase is an enzyme involved in the process by which atp is formed in the complete aerobic degradation of glucose or fatty acids; ribosomal rna forms part of the protein-synthesizing ribosomes; catalase catalyzes decomposition of hydrogen peroxide; acid phosphatase hydrolysis monophosphoric esters at acid ph; cytidylyltransferase is involved in phospholipid biosynthesis; and amino acid permease aids in transport of amino acids across membranes. a) name the marker molecule and give the number of the fraction that is most enriched for each of the following cell components: lysosomes; peroxisomes; mitochondria; plasma membrane; rough endoplasmic reticulum; smooth endoplasmic reticulum.

What is the difference between the conducting zone and the respiratory zone of the respiratory system? the conducting zone is a series of cavities and tubes that move air to the respiratory zone where gases exchange with the bloodstream. the conducting zone exchanges gases between the lungs and the alveoli and the respiratory zone is a series of cavities and tubes that move air to the conducting zone. the conducting zone moves oxygen into the cells and the respiratory zone takes carbon dioxide away from the cells. the conducting zone moves oxygen into the bloodstream and the respiratory zone takes carbon dioxide away from the bloodstream.

One gene can influence trait(s). one trait can be determined by gene(s).