Experiments are carried out to test a hypothesis by changing one variable at a time and including an unchanged variable called a(n) ______________

A dental student wants to test if fluoride is an effective additive against tooth decay. The student studies tooth decay in a population of people who live in neighborhoods supplied with fluoridated water. This student would like to ask whether access to fluoridated water prevents tooth decay. What would be an effective control group to ask this question? 

A student poses the question: How does the presence of dissolved salt affect the freezing point of water? To answer this question, the student set up two conditions. In the first condition, the student added salt to water in a container and referred to this condition as the variable. In the second condition, the student did not add any salt to water in a second container and referred to this condition as the control. The student took both containers and attempted to freeze the water at various temperatures to assess the freezing point. Would this be a valid experiment? 

Marlon is conducting a seed germination experiment. He places 3 groups of lettuce seeds in a 34º Celsius incubator with adequate moisture. One set of seeds is placed in a dark area with no light source. A second set is placed under artificial light and third set of seeds is placed in direct sunlight. This experiment is intended to test Phil's hypothesis that light is necessary for lettuce seed germination. Which of these conditions is the negative control?

Which of the following is not an indication that a hypothesis is NOT valid (“bad”)?

The following statements are true about all living things EXCEPT _____.

Which of the following is NOT one of the characteristics of living organisms?

 A beautiful wood desk you may do your homework on was once a living tree, but after being cut down its tissues died. Now, it only exhibits what property of life? 

Based on hierarchical levels of biological organization, which of these choices represents the broadest level?

The proposal that one type of organism can change gradually into another type over a long period of time is known as: 

Which of the following bonds is the weakest?

ATP’s role as the energy currency of the cell depends on the functional group ______.

A covalent bond is best described as two atoms interacting due to _______.

Which element's isotope is commonly used to determine when biological samples such as fossils, were formed?    

Sue was monitoring the oil spill into the Gulf of Mexico from an oil tanker. From her observations, she noted that the oil was moving as large patches in the water. It did not appear as though the oil was dissolving into the water. Why did the oil not dissolve into the water?  

Which of the following does NOT dissolve easily in water?

The common basilisk lizard will run across water on its hind legs in an erect position when startled by predators. This lizard has large feet and flaps of skin along its toes. What properties of water allow this lizard to walk on water?   

Compared to pure water, a pH 8 solution ____.

Which of the following does NOT have a long backbone with side groups?

Elemental carbon has ______ valence electrons.

Trans fats ____.

The layer that forms the foundation of cell membranes is primarily composed of molecules called ________.

A modified form of cellulose found in the exoskeletons of insects and crustaceans is known as:  ___________________

Animals do NOT have the enzyme(s) needed to break down _____.

You have extracted yeast DNA by first growing up cells and then lysing them.  The resulting mixture contains DNase, an enzyme that cuts DNA.  In order to deactivate the DNase, you need to disrupt the enzyme's _____ structure.

Protein primary structure defines _______.

A protein is not fully formed until a polypeptide has ______.

RNA can _____, but DNA does not.

The DNA sequence capable of pairing with 5' CGATTAGT 3' is:

All RNA molecules have different ______ than in DNA.

ATP is different from RNA because ATP has _____.

Carla studies proteins on the outside of pathogenic bacteria.  Then proteins are anchored to the membrane with a glycolipid.  These are _____ proteins.

______ are primarily responsible for keeping the two layers of biological membranes together.

A friend gives you handpicked flowers, and you put them in plain tap water.  The cells of the plant stem are ____ to the water.

Which of the following best describes osmosis?

Carbon dioxide is a small, nonpolar molecule that can pass through membranes down a concentration gradient without using a carrier protein or channel.  The movement of carbon dioxide in and out of cells is _____.

Facilitated diffusion does not require a/an _______.

All prokaryotes and eukaryotes have _______.

The ER is a connected extension of the _____.

Acinar cells in the pancreas secrete digestive enzymes and have a lot of ____ compared to other cells in the body.

Macromolecules, such as polysaccharides, are formed by dehydration (condensation) reactions.

All cells arise from pre-existing cells

All atoms (except hydrogen) contain at least one neutron, proton, and electron.