Bio unit 1 quiz

As shown in the diagram, when environmental temperatures drop below freezing, a layer of ice typically forms on the surface of bodies of freshwater such as lakes and rivers.

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

Tags

NGSS.MS-LS1-5

Water molecules are polar covalent molecules. There is a partial negative charge near the oxygen atom and partial positive charges near the hydrogen atoms due to the uneven distribution of electrons between the atoms, which results in the formation of hydrogen bonds between water molecules. The polarity of water molecules contributes to many properties of water that are important for biological processes.

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

• 
• 
• 
• 

In vascular plants, water flows from root to leaf via specialized cells called xylem. Xylem cells are hollow cells stacked together like a straw. A student explains that evaporation of water from the leaf pulls water up from the roots through the xylem, as shown in Figure 1.

Figure 1. Model of water movement through the xylem, with magnified models of water movement in the stem and leaf.

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

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

• 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.

• 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.

Tags

NGSS.MS-ESS2-4

The figure shows the results of an experiment to investigate the effects of an enriched CO

2

environment on plant growth. Identical plants were separated into different groups and grown either in a standard CO

2

environment (400 ppmCO

2

) or in an enriched CO

2

environment (700 ppm CO

2

). Of the plants in each environment, half were grown under ideal conditions and half were grown under stressed conditions.

Based on the figure, which statement best describes the observed relationship between atmospheric CO

2

enrichment and plant growth under ideal and stressed conditions?

• The increase in atmospheric CO

  2

  CO2 resulted in a greater increase in plant growth under stressed conditions than under ideal conditions.

• The increase in atmospheric CO

  2

  CO2 resulted in an inhibition of plant growth under both ideal and stressed conditions.

• The increase in atmospheric CO

  2

  CO2 resulted in a greater increase in plant growth under ideal conditions than under stressed conditions.

• The increase in atmospheric CO

  2

  CO2 had no observable effect on plant growth under either ideal or stressed conditions.

Tags

NGSS.HS-LS1-5

NGSS.HS-LS2-5

NGSS.HS-LS2-6

Phosphorous (P) is an important nutrient for plant growth. Figure 1 shows Arabidopsis thaliana plants grown under phosphorus‐sufficient (left) and phosphorus‐starved (right) conditions for six weeks.

• The phosphorus-starved plant was unable to synthesize both the required proteins and carbohydrates, limiting growth.

• The phosphorus-starved plant was unable to synthesize both the required nucleic acids and lipids, limiting growth.

• The phosphorus-starved plant was unable to synthesize both the required carbohydrates and nucleic acids, limiting growth.

• The phosphorus-starved plant was unable to synthesize both the required proteins and lipids, limiting growth.

Tags

NGSS.HS-LS1-6

A polypeptide is polymer of amino acids held together by peptide bonds. The process of dehydration synthesis creates these peptide bonds, as shown in Figure 1.

As shown in Figure 1, an amino acid must have which of the following properties in order to be incorporated into a polypeptide?

• An R-group

  R-group that is compatible with the R-group

  R-group of the last amino acid incorporated

• A central carbon atom that reacts with a nitrogen atom to form the peptide bond

• The ability to remain stable in the presence of water molecules

• The ability to form a covalent bond with both its NH

  2

  NH2 group and its COOH

  COOH group

Which of the following is common feature of the illustrated reactions showing the linking of monomers to form macromolecules?

• Monomers are joined by ionic bonds, and a water molecule is produced.

• Two different monomers are joined by a covalent bond.

• Monomers are joined by a covalent bond, and a water molecule is produced.

• Two identical monomers are joined by a covalent bond.

Tags

NGSS.HS-LS1-6

Which of the following describes a key difference among the 20 amino acids that are used to make proteins?

• Only some amino acids have an R-group

  R-group.

• Some amino acids are hydrophobic.

• Some amino acids contain the element phosphorus.

• Some amino acids contain the element phosphorus.

Figure 1 shows three amino acids that are part of a polypeptide chain. Figure 2 shows the same section of the chain after a mutation has occurred.

How might this change affect the structure and function of the protein?

• The new amino acid, valine, has replaced cysteine in the new protein. Since the number of amino acids has remained the same, there will be no change in the three-dimensional folding, or function, of the protein.

• Since this is a linear section, it does not influence protein folding. Thus, there will be no change in protein structure or function.

• Since the new amino acid is bounded on one side by an amino acid with a negatively chargedR-group

  R-group and by an amino acid on the other side with a positively charged R-group

  R-group, the charges will balance and the protein will fold as usual.

• The R-group

  R-group of the new amino acid, valine, has different chemical properties than the R-group

  R-group of cysteine. This will cause the protein to misfold and not function properly in the cell.

Tags

NGSS.HS-LS1-6

NGSS.HS-LS3-2

Figure 1 shows a short segment of a double-stranded nucleic acid molecule.

Which of the following statements is correct about the molecule shown in Figure 1 ?

• It is DNA

  DNA because of the nature of the hydrogen bonds between guanine and cytosine.

• It is RNA

  RNA because of the number of different nucleotides found in the molecule.

• It is DNA

  DNA because of the nucleotides present.

• It is RNA

  RNA because of the relative direction of the two strands.

Tags

NGSS.HS-LS1-1