AP Biology Unit 1 Progress Check

Which feature of model 1 best illustrates how biological information is coded in a molecule?

• The and labels at the ends of each strand

• The labeling of the hydrogen bonds between base pairs

• The lines connecting sugars and phosphate groups that represent covalent bonds

• The linear sequence of the base pairs

Figure 1 represents a segment of. Radiation can damage the nucleotides in a molecule. To repair some types of damage, a single nucleotide can be removed from a molecule and replaced with an undamaged nucleotide. Which of the four labeled bonds in Figure 1 could be broken to remove and replace the cytosine nucleotide without affecting the biological information coded in the molecule?

• Bond only

• Bond only

• Bonds Y and Z at the same time

• Bonds and at the same time

A student wants to modify model 1 so that it represents an double helix instead of a double helix. Of the following possible changes, which would be most effective in making model 1 look more like than?

• Changing the sequence of the base pairs

• Changing the deoxyriboses to riboses by adding groups

• Changing the shapes of the nitrogenous bases to match those shown in model 2

• Changing the sugar-phosphate backbone to a ribbon, as shown in model 3

Based on Figure 1, which of the following best compares the atomic structures of starch and cellulose?

• Starch is composed of carbon, hydrogen, and oxygen, while cellulose also contains nitrogen.

• Starch and cellulose are composed of repeating glucose monomers; however, in cellulose every other glucose monomer is rotated 180 degrees.

• Starch is composed of monomers that each have a group, while cellulose only has a group on every other monomer.

• Starch and cellulose are composed of identical monomers and therefore have identical structures.

Which of the following statements best describes the different functions of starch and cellulose in plants?

• The differences in the assembly and organization of the monomers of these two polymers result in different chemical properties.

• Since starch and cellulose are composed of identical monomers, the cellular environment where they are located controls their function.

• The monomers of cellulose are connected by covalent bonds, making it idea for structural support.

• The monomers of starch are connected by ionic bonds, making it ideal for energy storage for plants.

Which of the following best describes the process that adds a monosaccharide to an existing polysaccharide?

• The monosaccharide is completely broken down by a specific enzyme and then the atoms are reorganized and made into a polysaccharide.

• Ionic bonds are formed between adjacent carbon atoms of the monosaccharide and the polysaccharide by adding water and a specific enzyme.

• A specific enzyme removes the hydrogen from the monosaccharide and the hydroxide from the polysaccharide, creating a bond between the two and creating a water molecule.

• A specific enzyme removes two hydroxides, one from the monosaccharide, and one from the polysaccharide, creating a bond between the two monosaccharides and creating a hydrogen peroxide molecule.

Which of the following would most likely occur if cattle lost the ability to maintain a colony of microorganisms in their digestive tract?

• Cattle would no longer be able to synthesize cellulose.

• Cattle would have to convert cellulose to starch before digesting it.

• Cattle would have to start producing enzyme without the help of the bacteria.

• Cattle would no longer be able to use cellulose as a primary source of glucose.

Tags

NGSS.HS-LS2-3

Which of the following best describes how the structure of ice benefits the organisms that live in the water below?

• The water molecules in ice are closer together than those in liquid water, so the ice prevents the passage of air to the water, maintaining a constant gas mixture in the water.

• The water molecules in ice are closer together than those in liquid water, so the ice forms a barrier that protects the organisms in the water from the freezing air temperatures.

• The water molecules in ice are farther apart than those in liquid water, so the ice floats, maintaining the warmer, denser water at the lake bottom.

• The water molecules in ice are farther apart than those in liquid water, so the ice floats, preventing the escape of gases from the liquid water.

Which of the following models best demonstrates the arrangement of hydrogen bonds between adjacent water molecules?

• Model A

• Model B

• Model C

• Model D

Which statement describes how water is pulled up through the xylem to the leaves of the plant?

• As water exits the leaf, hydrogen bonding between water molecules pulls more water up from below.

• As water exits the leaf, signals are sent to the roots to pump more water up to the leaves through the xylem by adhesion.

• Evaporation from the leaf decreases the hydrogen bonds that form between the water molecules in the xylem, which helps the water molecules to be pulled up the xylem.

• Evaporation of water from the leaf increases the hydrogen bonds that form between water molecules in the air, providing the energy for transport.

Tags

NGSS.MS-LS2-3