Unit 2 test answers

Students are given data from an investigation that identified some of the chemical elements present in four different samples. Which sample was most likely DNA?

• Sample 4 because iron, oxygen, and magnesium help organisms transport oxygen in the blood for cellular respiration.

• Sample 1 because hydrogen, phosphorus, and nitrogen along with carbon are used in storing and transmitting genetic information.

   

• Sample 3 because calcium, potassium, and nitrogen are essential metals found in all living organisms and are used in storing and transmitting genetic information.

• Sample 2 because aluminum, silicon, and copper are the base pairs of DNA, which transmit chemical information.

 

Students studying the function of macromolecules learned that glycogen is found in the liver of animals as different as a polar bear and a tiny mouse. Based on the structural diagram below, which of the following claims can be made about Glycogen?

• Glycogen is stored and used to build muscle tissue.

• Glycogen is hydrolyzed to glucose and used as energy to help carry out daily functions.

• Glycogen is converted to DNA for cell division.

• Glycogen is combined with other macromolecules to be used in meiosis.

A student states that because nucleic acids contain sugar, they are an energy storage molecule. Using the diagram below, which statement accurately describes why this student’s claim is correct or incorrect?

• The student’s claim is correct because base pairs are a method of storing energy inside the cell’s cytoplasm

• The student’s claim is incorrect because the base pairs create a unique code that allows for passing on genetic information.

• The student’s claim is correct because the base pairs can be broken and energy released for cellular processes.

• The student’s claim is incorrect because the base pairs work as enzymes to catalyze cellular reactions important for metabolism.

 

Amylase is an enzyme found in saliva that breaks down starch. In his lab report, a student claims that as amylase breaks down starch in the mouth, the amount of amylase will decrease. Which evidence from the chart disproves this student’s claim? Select TWO answers from the list below

• The concentration of starch decreases by the end of the reaction.

• Energy is being converted into chemical bonds throughout the reaction.

• At the end of the reaction, the concentration of amylase is equal to the concentration of glucose.

• Throughout the reaction, glucose is being converted into starch.

• The concentration of amylase remains constant throughout the reaction.

 

Listed below are properties of 4 major Biological Molecules. Use the chart to answer these questions. Based on the properties listed in the chart, which of the macromolecules would best act as a barrier to loss of water from a cell?

• Macromolecule D

• Macromolecule A

• Macromolecule B

• Macromolecule C

In the graphs below, Reaction Rate in the presence of an enzyme peaks at a specific temperature independent of substrate concentration. Despite the presence of abundant substrate, as temperature increases the reaction rate begins to decrease. Which of the arguments below BEST explains this phenomenon?

• extreme temperatures, the substrate denatures and can no longer bind their enzyme.

• At extreme temperatures, enzymes denature and their active site can no longer bind their substrate.

• At extreme temperatures enzymes are unable to release their substrates to bind new ones.

• At extreme temperatures chemical reactions between enzyme components and substrate components are unable to form chemical bonds.

 Listed below are properties of 4 major Biological Molecules. Use the chart to answer these questions. Which of the following statements best support the claim that the molecule identified in the question above would be ideal as a water barrier?

• The Polar molecule with N and P elements repels water using those elements.

• The Polar molecule dissolves water and neutralizes its loss by using energy.

• The non-polar molecule does not dissolve in water and actually repels it.

• The Large Globular molecule is a structural component that closes pores in the cell.

What type of Macromolecule is pictured below?*

• Lipid

• Nucleic Acid

• Carbohydrate

• Protein

 

DNA stores

• protein

• carbohydrates

• hereditary information

• fat

A molecule that has a partial positive charge on one side and a partial negative charge on the other side is called a

• polar molecule.

• nonpolar molecule.

• charged molecule.

• bipolar molecule.