The drawings below show a young sunflower plant at different times of the day.
Which of the following describes the plant's movement?
A.
It bends away from the pull of gravity.
B.
It bends away from light.
C.
It bends toward light.
D.
It bends toward water.
C. It bends toward light.
What is the role of carbohydrates in animal cells?
A.
synthesizing proteins
B.
developing enzymes
C.
storing energy
D.
protecting the cell wall
C. Storing energy
Why does active transport require energy to move molecules of a substance across a cell membrane?
A.
Lack of the substance makes the cell weak.
B.
The substance moves from low to high concentration, against the concentration gradient.
C.
The cell membrane is very thick.
D.
The substance moves from high to low concentration, with the concentration gradient.
B. The substance moves from low to high concentration, against the concentration gradient.
An investigation is set up to study the movement of water through a membrane. The results are shown in the diagram.
Based on these results, which statement correctly predicts what will happen to red blood cells when they are placed in a beaker containing a saltwater solution that has a salt concentration much higher than that of the red blood cells?
Without the diagram or any specific information about the results, it is not possible to make an accurate prediction.
The table shows the direction and function of substances in a chemical reaction that takes place in the chloroplasts of plant cells. The table is missing a title and information at W, X, and Y.
Title:____________________
Substance Direction In the Reaction
(In or Out) Function In the Reaction
Carbon dioxide In Used to make other substances containing carbon
Oxygen Out Is a product of the chemical reaction
W In Provides the main energy source for the reaction
Sugar molecules X Y
Water In Splits and is used to provide oxygen and hydrogen atoms for the reaction
What is the direction, X, and function, Y, for the sugar molecules?
A.
Direction X is out; function Y is to provide chemical energy for the plant cell.
B.
Direction X is in; function Y is to provide heat energy for the plant cell.
C.
Direction X is out; function Y is to form more chlorophyll for the plant cell.
D.
Direction X is in; function Y is to form large sugar molecules for the plant cell.
D. Direction X is in; function Y is to form large sugar molecules for the plant cell.
The model shows an animal cell.
The image shows the organelles within an animal cell. The ribosomes, nucleus, mitochondrion, cell membrane, and Golgi apparatus are labeled.
Which describes an interaction between the Golgi apparatus and another organelle to maintain the cell's homeostasis?
A.
The Golgi apparatus stores nutrients provided by the mitochondria.
B.
The Golgi apparatus sorts and packages proteins created by ribosomes.
C.
The Golgi apparatus collects genetic information to be used by the nucleus.
D.
The Golgi apparatus sends and receives chemical signals for the membrane.
B. The Golgi apparatus sorts and packages proteins created by ribosomes.
Which equation best summarizes the overall reactions of photosynthesis?
A.
6CO2 + 6O2 → C6H1206 + 6H2O
B.
6O2 + C6H1206 → 6CO2 + 6H2O
C.
6O2 + 6H2O + 6O2 → C6H1206
D.
6CO2 + 6H2O → C6H1206 + 6O2
D. 6CO2 + 6H2O → C6H1206 + 6O2
Viruses reproduce through the use of host cells. In this process, viruses reproduce by injecting their DNA into the host cell and using the cell's structures to create copies of itself. After numerous copies are made, the host cell bursts and the new viruses are released. Depending on the type of virus and the host cell, hundreds or thousands of viruses can be released in this burst. These viruses then go on to reproduce through new host cells. Bacteria, however, reproduce using binary fission. In this process, a bacterium splits into two identical daughter cells. In favorable conditions, bacteria can divide once every 20 minutes. This means that a single bacterium can turn into a colony of over a billion bacteria in about ten hours. Which statement correctly compares viral and bacterial reproduction?
A.
Both viruses and bacteria can reproduce without the help of other organisms.
B.
Both viruses and bacteria can create large populations in a short time period.
C.
Both viruses and bacteria must destroy themselves after they have reproduced.
D
.
Both viruses and bacteria must have very large populations in order to reproduce.
B. Both viruses and bacteria can create large populations in a short time period.
The diagram shows a cell.
The cell is green and rectangular with two outer layers. The cell contains various organelles inside it. An organelle labeled Y has a double membrane, with layers folded inside it. An organelle labeled Z is green and has stacks of cylindrical disks inside it.
Which statement BEST describes how the organelles labeled Y and Z work together to maintain homeostasis in the cell?
A.
Organelle Y creates sugar and oxygen, which organelle Z uses to release energy.
B.
Organelle Z creates sugar and oxygen, which organelle Y uses to release energy.
C.
Organelle Y creates protein for food, which organelle Z uses to release energy.
D.
Organelle Z creates protein for food, which organelle Y uses to release energy.
A.
Organelle Y creates sugar and oxygen, which organelle Z uses to release energy.
A student is investigating cellular transport. They fill a beaker with 250 ml of water. The student then places 10 drops of red food coloring into the beaker of water and makes an observation immediately, after 5 minutes, and after 30 minutes. The student's set up is shown.
Three beakers contain water molecules and dye molecules. The first beaker is labeled 'Adding the dye' and shows the dye molecules closely packed in a circle. The second beaker is labeled 'After 5 minutes' and the dye molecules are starting to move apart. The third beaker is labeled 'After 30 minutes' and the dye molecules are evenly dispersed within the water molecules.
The student observes that the molecules of red dye move from an area of higher concentration to an area of lower concentration until equilibrium is reached. Which BEST describes the type of cellular transport that the student is investigating?
A.
The student is investigating the active transport of diffusion.
B.
The student is investigating the active transport of osmosis.
C.
The student is investigating the passive transport of osmosis.
D
.
The student is investigating the passive transport of diffusion.
D. The student is investigating the passive transport of diffusion.
The table shows the pH ranges that support the growth of different bacteria.
Bacteria pH range
Salmonella 3.6–9.5
Listeria monocytogenes 4.2–9.6
Escherichia coli 4.3–9.0
What happens to these organisms at a pH of 3.7?
A
.
Salmonella, Listeria monocytogenes and Escherichia coli do not grow.
B.
Listeria monocytogenes grows. Salmonella and Escherichia coli do not grow.
C.
Salmonella grows. Listeria monocytogenes and Escherichia coli do not grow.
D.
Escherichia coli grows. Listeria monocytogenes and Salmonella do not grow.
C. Salmonella grows. Listeria monocytogenes and Escherichia coli do not grow.
A group of students conducts research on enzyme activity and collects the data shown in the graphs.
There are two graphs. The first graph has increasing enzyme activity on the y-axis and temperature, in Celsius, on the x-axis. The line increases at a steady rate until about 37 degrees Celsius, then quickly decreases. The second graph has increasing enzyme activity on the y-axis and pH on the x-axis. The line slowly increases until there is a pH of between 6 and 8, then starts to decrease.
Which statement is supported by the evidence in the graphs?
A.
The enzyme is very active at approximately 42°C and within a pH range of 2 to 6.
B.
The enzyme functions well at a temperature of 35°C and would be active at any pH value.
C.
The enzyme works best in a pH range of 6 to 8 and at a temperature of approximately 37° C.
D.
The enzyme's activity is greatest at pH 7 and would not be affected by a change in temperature.
C. The enzyme works best in a pH range of 6 to 8 and at a temperature of approximately 37°C.
Which table correctly compares a virus and a living organism?
A virus and a living organism have significant differences in their structures and functions. However, here is an example of a table that could compare some key characteristics:
| Characteristic | Virus | Living Organism |
|-------------------|------------------------|-------------------------|
| Structure | Consists of genetic material (DNA or RNA) surrounded by a protein coat | Composed of organized cellular structures containing genetic material |
| Reproduction | Replicates by infecting host cells and hijacking their machinery | Reproduces through cellular division or sexual reproduction |
| Metabolism | Lacks a metabolic system and relies on host cell's resources | Possesses a metabolic system for obtaining and utilizing energy |
| Growth | Does not experience growth | Exhibits growth through cellular division |
| Response to stimuli| Lacks the ability to respond to environmental stimuli | Can sense and respond to external/internal stimuli |
| Evolution | Does not evolve, but can undergo genetic variation through mutations | Evolves over time through natural selection and genetic variation |