Cells

Question 1

A student adds yeast cells to a flask of liquid media containing glucose. The flask is sealed and allowed to sit for a period of time.

What substance would increase if the yeast cells are performing fermentation?

Answer 1

alcohol

B.C.2

Question 2

What is a hypotonic solution?

Answer 2

A solution with a low concentration of solute.

Question 3

One theory that explains the origin of eukaryotic cells suggests that they resulted from large prokaryotic cells engulfing smaller prokaryotic cells. These smaller engulfed cells then contributed to the homeostatic needs of their new hosts.

Answer 3

Mitochondria have their own DNA.

B.C.1

Question 4

Which structures are found in eukaryotic cells but not in prokaryotic cells?

Answer 4

• Mitochondria
• Nucleus

Question 5

Oxygen in Earth’s early atmosphere was generated by marine organisms such as cyanobacteria, which are sometimes called blue-green algae.

What process did cyanobacteria use to oxygenate Earth’s early atmosphere?

Answer 5

Photosynthesis.

B.C.2

Question 6

Which graph shows the effects of temperature on the activity of an enzyme?

Answer 6

B.C.2

Question 7

A student fills a beaker with a 5% salt solution. The student places a dialysis bag containing a 15% salt solution into the beaker. Then the student measures the salinity of the salt solution in the beaker after 5 minutes. The dialysis tubing is permeable to salt and water.

PART A: Which direction does the water move immediately after placing the dialysis tubing in the beaker?

Answer 7

Water moves into the tubing.

B.C.1

Question 8

A student fills a beaker with a 5% salt solution. The student places a dialysis bag containing a 15% salt solution into the beaker. Then the student measures the salinity of the salt solution in the beaker after 5 minutes. The dialysis tubing is permeable to salt and water.

PART B: Which direction does the salt move immediately after placing the dialysis tubing in the beaker.

Answer 8

Salt moves out of the tubing.

B.C.1

Question 9

Which element is found in all living cells on Earth?

Answer 9

Carbon.

B.C.1

Question 10

A protein is built from several polypeptides, each with a different three-dimensional folding pattern.

What causes polypeptides to have different folding patterns?

Answer 10

The polypeptides are composed of different amino acid sequences.

B.C.2

Question 11

For normal nerve transmission in mammals, nerve cells maintain specific concentrations of potassium (K+) and sodium (Na+) ions. Concentrations of Na+ ions are normally higher outside the cell and lower inside the cell, while K+ ions are normally lower outside the cell and higher inside the cell. However, cell membranes are impermeable to Na+ and K+ ions. The diagram shows the relative concentrations of ions in solution inside and outside the cell.

Which process describes how a nerve cell maintains homeostasis in regards to the Na+ and K+ ion concentrations?

Answer 11

by transporting both types of ions through protein pumps within the cell membrane

B.C.1

Question 12

The transcription of a DNA molecule into an mRNA molecule, and the translation of that mRNA molecule, can occur simultaneously in prokaryotic cells. This does not occur in eukaryotic cells.

Which statement explains why transcription and translation can occur simultaneously in prokaryotic cells but not in eukaryotic cells?

Answer 12

Prokaryotic cells lack a nucleus to separate the two processes.

B.C.1

Question 13

What do eukaryotic cells lack that affects their ability to translate mRNA for protein synthesis?

Answer 13

Eukaryotic cells lack ribosomes

B.C.1

Question 14

What is the main difference between prokaryotic and eukaryotic cells regarding energy production?

Answer 14

Prokaryotic cells have more mitochondria to produce energy

B.C.1

Question 15

Fill in the blank

Eukaryotic cells do not create amino acids until ??? is complete.

Answer 15

transcription

B.C.1

Question 16

The graph shows the relative enzymatic activity among four different enzymes.

Which enzyme would be most efficient in an environment where the pH level can fluctuate between acidic and basic?

Answer 16

Enzyme C

B.C.2

Question 17

The graph shows the relative enzymatic activity among four different enzymes.

What would happen if enzyme A was placed in an environment with a pH of 9?

Answer 17

Enzyme A would slow or stop functioning.

B.C.2

Question 18

Chemosynthesis is a cellular process used by organisms in deep sea ecosystems in the absence of light. A chemical equation for chemosynthesis is shown.

How is chemosynthesis different from photosynthesis?

Answer 18

Chemosynthesis harvests energy from other chemical compounds.

B.C.2

Question 19

A student performs an experiment to study the transport of water in and out of cells. He uses clear, semi-permeable plastic bags to represent the cell membrane. The student places three plastic bags of the same size, each containing a 1% concentration sucrose solution, into three different beakers. One beaker contains distilled water, another beaker contains a 3% concentration sucrose solution, and the third beaker contains a 1% concentration sucrose solution. The diagram shows the student’s experimental setup, the plastic bag before it is placed in the beakers, and the appearance of the bags after an hour in each solution.

Which statement provides a conclusion about the transport of water in and out of cells based on the results of the student’s experiment?

Answer 19

Water movement into the cell is dependent on the percent concentration of solutes both inside and outside the cell.

B.C.1

Question 20

Chief cells are found in the glands that line the inside of the stomach. These cells secrete large amounts of enzymes to aid in food digestion.

Which cellular structure is more abundant in chief cells due to their high rate of enzyme secretion?

Answer 20

endoplasmic reticulum

B.C.1

Question 21

What type of macromolecule stores energy and provides thermal insulation for the body?

Answer 21

lipid

B.C.1

Question 22

Which structure helps classify an organism as eukaryotic?

Answer 22

nucleus

B.C.1

Question 23

Which pair of organelles works together to give structure and support in animal cells?

Answer 23

cell membrane and cytoskeleton

B.C.1

Question 24

Which cell specimen is a prokaryote?

Answer 24

Cell C

Prokaryotes do not have a nucleus and often lack membrane-bound organelles.

B.C.1

Question 25

True or False: Chemosynthesis can occur in environments with sunlight.

Answer 25

False ## Footnote Chemosynthesis occurs in the absence of light, unlike photosynthesis.

Question 26

Which structural feature of the cell membrane allows molecules such as oxygen and carbon dioxide to diffuse into and out of the cell?

Answer 26

The cell membrane is made up of two layers of phospholipids. ## Footnote B.C.1

Question 27

# Identify two cell structures involved in the function described: Modify proteins and transport them out of the cell.

Answer 27

2 and 6 ## Footnote B.C.1

Question 28

What are the appropriate transport mechanisms for each particle across the cell membrane?

Answer 28

Channel, Phospholipids, ATP Pump These mechanisms correspond to passive and active transport processes. ## Footnote B.C.1

Question 29

True or False: The movement across the membrane requires energy from ATP.

Answer 29

False The movement across the membrane does not require added energy when particles are uncharged and small. ## Footnote B.C.1

Question 30

Students in a biology class conduct an experiment to determine the effect of temperature on the rate of photosynthesis in a plant. They place an Elodea plant into a test tube filled with water. Then, the students place the test tube under a light and slowly increase the temperature of the water. They record their results and display them on a graph as shown. **Explain the effect of temperature on the rate of photosynthesis.**

Answer 30

Enzymes involved with plant photosynthesis are disrupted at temperatures above 25°C ## Footnote B.C.2

Question 31

A scientist isolates a number of non-photosynthetic prokaryotes. Which structure would be found in these cells?

Answer 31

cell walls ## Footnote B.C.1

Question 32

A red blood cell is placed into an aqueous solution. The red blood cell has a lower concentration of protein and sugar than the aqueous solution, as shown in the diagram. In the diagram, the volume of the cell is equal to the volume outside the cell. **What is most likely to occur?**

Answer 32

Water from the red blood cell will diffuse into the solution ## Footnote B.C.1

Question 33

Which structures are present in animal cells?

Answer 33

DNA, Nucleus, Ribosome ## Footnote B.C.1

Question 34

Animal cells store energy in the form of organic molecules. Which organic molecules are primarily used to store energy?

Answer 34

lipids ## Footnote B.C.1

Question 35

A student places a marine plant in fresh water. Which statement describes a response of the cells in the plant stem?

Answer 35

The cells will expand ## Footnote B.C.2

Question 36

Answer 36

## Footnote B.C.1

Question 37

The diagram shows an incomplete cross-section of a cell membrane. Three different particles are shown moving across the membrane into or out of the cell. Determine the appropriate transport mechanism of each particle and move the correct membrane segment into each blank box to complete the cross-section diagram.

Answer 37

## Footnote B.C.1

Question 38

The diagram models the time-lapse movement of particles across a cell membrane. The particles have characteristics that allow them to pass freely across the membrane. **Describe the particles or their movement based on the time-lapse diagram.**

Answer 38

* The particles crossing the membrane do not have a charge * The movement across the membrane does not require added energy * The particles crossing the membrane could be water (H2O) or oxygen (O2) ## Footnote B.C.1

Question 40

Which structures are present in bacteria cells?

Answer 40

Cell Wall, DNA, Ribosome ## Footnote B.C.1