Science Practices
In a study, researchers observed that students who sleep longer tend to score higher on biology exams. Does this observation prove that more sleep causes better exam performance? Why or why not?
No, the observation does not prove that more sleep causes better exam performance. It shows a correlation, but other factors (like study habits, nutrition, or stress levels) could be influencing both sleep and scores. Correlation does not imply causation.
Which of the following structures is found in eukaryotic cells but not in prokaryotic cells?
A. Ribosomes
B. Nucleus
C. Cell membrane
D. Cytoplasm
B. Nucleus
Which organelle is responsible for producing energy in the form of ATP?
A. Nucleus
B. Ribosome
C. Mitochondrion
D. Golgi apparatus
C. Mitochondrion
Which of the following best describes osmosis?
A. The movement of solutes from high to low concentration
B. The movement of water from low to high concentration
C. The movement of water across a selectively permeable membrane from high to low water concentration
D. The movement of gases across a membrane
C. The movement of water across a selectively permeable membrane from high to low water
IV = what you change in experiment
DV = what you measure (cm, g, in.)
A student increases the magnification on a microscope to better observe a specimen but finds the image becomes blurry. What is the likely issue, and how does resolution differ from magnification in this context?
The issue is likely with resolution, not magnification. Increasing magnification makes the image larger, but if the resolution is low, the image becomes blurry and details are lost.
True or False: Both prokaryotic and eukaryotic cells can carry out all basic life functions, such as metabolism and reproduction.
Despite structural differences, both cell types perform all necessary life processes.
TRUE
What is the primary function of ribosomes in a cell?
A. Transport substances
B. Make proteins
C. Store genetic material
D. Digest waste
B. Make proteins
True or False
Diffusion requires energy from the cell to occur.
False: Diffusion is a passive process—it does not require energy (ATP) because molecules move down their concentration gradient.
What is the main job of the cell membrane in cells?
It is selectively permeable meaning it allows certain things to enter and exit the cell.
During a plant growth experiment, a student records that the leaves are “greener” and that the plant grew 5.2 cm in one week. Identify which observation is qualitative and which is quantitative, and explain why.
"The leaves are greener" is a qualitative observation because it describes a quality using words, not numbers.
"The plant grew 5.2 cm" is a quantitative observation because it includes a numerical measurement.
Name two types of organisms that are made up of prokaryotic cells.
Bacteria & Archaea
Which organelle modifies, sorts, and packages proteins for secretion?
A. Endoplasmic reticulum
B. Nucleolus
C. Golgi apparatus
D. Lysosome
C. Golgi apparatus
What happens to an animal cell placed in a hypotonic solution?
Water enters the cell by osmosis, causing it to swell and potentially burst (lyse).
Which type of cell has membrane-bound organelles?
A. Prokaryotic
B. Eukaryotic
C. Bacterial Cells
B. Eukaryotic
A biology class measures the mass of a frog four times using a scale. The results are 12.1 g, 12.2 g, 12.1 g, and 12.2 g. The actual mass is 13.5 g. Are the measurements accurate, precise, both, or neither?
The measurements are precise but not accurate. Precision refers to how consistent the measurements are (which they are), while accuracy refers to how close the measurements are to the actual value (which they are not).
Which of the following features is shared by both prokaryotic and eukaryotic cells?
A. Membrane-bound organelles
B. DNA
C. Nucleus
D. Mitochondria
B. DNA
Which organelle is found only in plant cells and is the site of photosynthesis?
A. Chloroplast
B. Ribosome
C. Nucleus
D. Smooth ER
A. Chloroplast
What happens to a plant cell when it is placed in a hypertonic solution?
A. It swells and may burst
B. It stays the same size
C. It becomes turgid
D. It loses water and the cell membrane pulls away from the cell wall
D. It loses water and the cell membrane pulls away from the cell wall
A student wants to identify an organelle that is responsible for photosynthesis. Which cell and organelle should the student examine?
a. Animal cell – Mitochondria
b. Plant cell – Chloroplast
c. Animal cell – Nucleus
d. Plant cell – Golgi apparatus
b. Plant cell – Chloroplast
The number of bacterial colonies on five petri dishes after incubation were: 32, 28, 30, 34, and 26. What is the mean number of bacterial colonies?
Add the data:
32 + 28 + 30 + 34 + 26 = 150
Divide by the number of data points (5):
150 ÷ 5 = 30
Animal and Plant Cells are Eukaryotic Cells. What is the major difference between these two cell types?
Animal: Does not have cell wall and chloroplast
Plants: Have cell wall and chloroplasts
Which organelle contains digestive enzymes and helps break down cellular waste?
A. Vacuole
B. Mitochondrion
C. Lysosome
D. Chloroplast
C. Lysosome
True or False:
Diffusion & Osmosis are the same thing?
False: Diffusion has to do with all type of molecules moving into and out of cell from HIGH to LOW but OSMOSIS refers to movement of WATER ONLY into and out of the cell from HIGH TO LOW.
Soaking a salt water fish in a hypotonic solution (fresh water) would do what to the fish?
Cause its cells to take in water by osmosis, leading to cell swelling/burst and potentially cell damage or death.