Benchmark 2 Reteach

Benchmark 2 Reteach

​Scientific Method

​It is important to know how scientists set up experiments using the scientific method. One thing to review is the different types of scientific variables.

Multiple Choice

The dependent variable in this experiment was

• Number of Bacteria

• Culture Number

• Time of Incubation

• Type of Bacteria

Multiple Choice

What is a control group in an experiment?

• the manipulated group

• a group in an experiment that changes to compare the IV and DV variables

• the group that is altered

• a group in an experiment that remains unchanged for purpose of comparison (missing the IV)

Multiple Choice

Read the paragraph and then answer the question below:

An experiment was designed to investigate the effect of caffeine on the heartbeat of water fleas. Two populations of water fleas were cultured. Both populations had water with the same mineral content, were supplied with identical amounts of bacteria as food, received the same amount of light, and had their temperature maintained at 20°C. Every two hours, water fleas from both populations were selected and their heartbeats were checked. The fleas of population #1 had caffeine administered five minutes before their heartbeat was checked. The fleas in population #2 were given nothing.

What part of the experiment was the heartbeat?

• dependent variable

• independent variable

• control group

• experimental group

• constants

Water

Water is a polar molecule that has many amazing properties. Water molecules form hydrogen bonds with each other and form cohesive bonds to create surface tension. Adhesion is bonding with other materials like adhesive tape.

Multiple Choice

The diagram shows hydrogen bonds between water molecules. What describes each hydrogen bond?

• An attraction between positive ends of two molecules

• An attraction between negative ends of two molecules

• An attraction between the positive end of one molecule and the negative end of another molecule

• An attraction between neutral ends of two molecules

Multiple Choice

A common science experiment is to place a celery stalk into a glass of water and food coloring. After some time, the food coloring appears in the celery. What chemical principle is modeled by this experiment?

• The food coloring acts as a buffer, and the plant absorbs the food coloring in order to maintain a pH near 7.

• Water accounts for about 60 percent of the celery plant. The food coloring dissolves in the water in the celery and spreads throughout the plant.

• The celery can use the food coloring as an energy source.

• The food coloring molecule carries a charge, and is attracted to oppositely charged molecules in the plant.

• The food coloring dissolves in the water in the glass. The water rises through vessels in the celery stem by capillary action, and carries the dissolved food coloring along with it.

​Macromolecules

​You need to know the structure and function of the 4 macromolecules: carbohydrates, lipids, proteins and nucleic acids.

Multiple Choice

Which of the following tables correctly matches the complex molecules and what they break down into?

Multiple Choice

 The diagram shows the structure of palmitic acid. What type of fatty acid is palmitic acid?

• it is monounsaturated

• it is saturated

• it is polyunsaturated

• it is a trans-fatty acid

Multiple Choice

In glucose, each carbon atom forms how many bonds, and of what type?

• one hydrogen bond

• one hydrogen and three covalent bonds

• four covalent bonds

• one hydroxyl bond

• four ionic bonds

Multiple Choice

 Which molecule is a sugar?

Multiple Choice

For which macromolecule does the student list an incorrect function?

• the lipids, because they are responsible for long-term energy storage

• the proteins, because they are responsible for helping plants retain water

• the carbohydrates, because they are responsible for the structure of the cell membrane

• the nucleic acids, because they are responsible for providing support for the immune system

Multiple Choice

The shape of a protein molecule is influenced by

• whether it is organic or inorganic.

• the number of chromosomes in the cell.

• its sequence of amino acids.

• the number of genes in the nucleus.

Multiple Choice

Experiments revealed the following information about a certain molecule.

• It can be broken down into amino acids.

• It can break down proteins into amino acids.

• It is found in high concentrations in the small intestine of humans.

To which of the following categories does this molecule belong?

• inorganic compound

• genetic hormone

• antigen

• enzyme

Multiple Choice

The picture is a major macromolecule. What best describes the function of this macromolecule?

• It is broken down to provide usable chemical energy.

• It stores and transmits genetic information.

• It transports oxygen in the blood.

• It helps plants retain water.

​Enzymes

​Enzymes are special proteins that can speed up chemical reactions by lowering the activation energy.

Multiple Choice

The graph below shows the effect of temperature on enzyme X's relative rate of action on a protein. What effect does the temperature have on enzyme X in the range of 55°C to 68°C?

• It denatures the enzyme and increases its ability to increase the rate of the reaction.

• It improves the enzyme's chemical structure and increases its affinity for the substrate.

• It denatures the enzyme and decreases its ability to increase the rate of the reaction.

• It improves the enzyme's chemical structure and decreases its affinity for the substrate.

Multiple Choice

Which of the following outcomes can be expected?

• The enzyme will be able to convert molecule A into molecules C and D at a faster rate.

• The enzyme will be able to reverse the reaction, combining molecules C and D into molecule A.

• The enzyme will only be able to convert molecule A into molecules C and D a few more times.

• The enzyme will no longer be able to aid in the reaction that breaks molecule A into molecules C and D.

Multiple Choice

The diagram below models an enzyme breaking down a complex carbohydrate called starch. If X represents what a starch molecule will break down into, then X could represent

• proteins.

• fatty acids.

• lipids.

• simple sugars.

​Prokaryotes vs Eukaryotes

​Find the following while watching the video:

Which one is bigger?

​Where is the DNA located in each type of cell?

​Which one contains a nucleus?

​

Multiple Choice

All living cells contain genetic material. Where is the genetic material stored in these cells?

• in a long strand of DNA floating free in the cytoplasm, because these cells are prokaryotic

• outside of these cells, in a single strand of DNA that passes from from cell to cell, because these cells are eukaryotic

• in DNA that is stored inside a membrane-bound nucleus, because these cells are prokaryotic

• outside of these cells, linked to the cell membrane that is carried with these cells, because these cells are eukaryotic

​Cell Membrane

​A cell membrane is also called a plasma membrane. It is a semi-permeable membrane which means it lets some things pass through but not others. It is made up of macromolecules and has a very important function in organisms.

Multiple Choice

A common function of proteins and carbohydrates in the plasma membrane is

• cell recognition and interaction.

• regulation of the cell cycle.

• synthesis and delivery of enzymes.

• transcription of DNA.

Multiple Choice

How does the structure of a phospholipid allow it to function as a cell membrane component?

• The non-polar regions of the phospholipid tails orient toward each other with the polar regions of the phospholipids pointing toward the inside of the cytoplasm or towards the outside of the cell.

• The inner non-polar region of the phospholipid bilayer is extremely attractive to water molecules, making the cell membrane semipermeable.

• Phospholipids can shift the polar regions and the non-polar regions so they can frequently rotate within the plasma membrane.

• Phospholipids are very polar therefore they disperse easily in water.

​Cell Organelles Structure and Function

​What does each organelle do in the cell?

​Which ones are involved in making protein? making energy? cleaning up the cell? structure?

Multiple Choice

Which structure is often referred to as the "post office of the cell" and packages, sorts, and delivers proteins?

• W

• X

• Y

• Z

Multiple Choice

The purpose of a lysosome is to

• contain digestive chemicals used to break down food.

• push and pull the other organelles throughout the cell.

• store food and deliver food to the Golgi apparatus.

• carry the genetic material in the cell to the mitochondrion.

Multiple Choice

Which two organelles have a double membrane and are both responsible for making energy in cells?

• nuclei and Golgi apparatuses

• vacuoles and lysosomes

• ribosomes and centrioles

• chloroplasts and mitochondria

Multiple Choice

Which of the following organelles have a transport function?

• ribosome and Golgi apparatus

• endoplasmic reticulum and Golgi apparatus

• endoplasmic reticulum and mitochondrion

• ribosome and mitochondrion

​Cell Processes

​

​We learned about a lot of different cell processes: cell transport (diffusion, osmosis, protein channels), photosynthesis, cell respiration (glycolysis, Krebs, electron transport chain, fermentation). Please review these and make sure you know the inputs and outputs of each.

Multiple Choice

The diagram below represents movement of a large molecule across a membrane. Which process is represented by this diagram?

• gene manipulation

• active transport

• diffusion

• protein building

Multiple Choice

Under what condition will diffusion take place most rapidly?

• movement through a permanent barrier

• movement against a concentration gradient

• movement from an area of high concentration to an area of low concentration

• movement from an area of low concentration to high concentration

Multiple Choice

Why does active transport require energy to move molecules of a substance across a cell membrane?

• Lack of the substance makes the cell weak.

• The substance moves from low to high concentration, against the concentration gradient.

• The cell membrane is very thick.

• The substance moves from high to low concentration, with the concentration gradient.

Multiple Choice

What term is used when the concentrations of solutes inside and outside a cell are in equilibrium?

• hypotonic

• isotonic

• hypertonic

• polytonic

Multiple Choice

Which of the following correctly describes characteristics for the cellular processes of exocytosis and endocytosis?

• Exocytosis involves the secretion of cellular materials, while during endocytosis vesicles are moved away from the plasma membrane.

• During exocytosis cell membranes fuse, while during endocytosis the plasma membrane decreases in size.

• Exocytosis involves infolding of the plasma membrane, while during endocytosis vesicles are moved toward the plasma membrane.

• During exocytosis vesicles are moved toward the plasma membrane, while during endocytosis the plasma membrane increases in size.

Multiple Choice

Which combination of molecules and temperature would diffuse faster?

• small molecules, high temperature

• large molecules, high temperature

• small molecules, low temperature

• large molecules, low temperature

Multiple Choice

Human red blood cells contain 0.9% sodium chloride as a component of their cytoplasm. What would happen if an IV solution containing 1.5% sodium chloride is introduced into a person?

• Their red blood cells would lose water across their cell membrane and begin to shrink.

• Their red blood cells would absorb water across their cell membrane and begin to swell.

• The red blood cells would first absorb water across their cell membrane, then lose water across their cell membrane.

• The red blood cells will first lose water across their cell membrane, then absorb water across their cell membrane.

Multiple Choice

The sodium-potassium pump functions to pump sodium ions out of the cell and potassium ions into the cell. Which type of transport does this statement describe?

• Active transport

• Passive transport

• Osmosis

• Diffusion