biology final3

How does a cilium differ from a flagellum?

Cilia appear in large numbers on the cell surface, and flagella do not.

Which of the following choices correctly describes the composition of a ribosome?

Contains RNA and proteins A ribosome is made of RNA and proteins. Each ribosome consists of two complexes: the small and large subunits. Ribosomes are responsible for protein synthesis.

Which of the following is true regarding plasmodesmata?

Plasmodesmata allow for neighboring plant cells to transport ions, water, and other substances. Plasmodesmata allow for cytoplasmic exchange to occur between two plant cells.

Which of the following is a function of the extracellular matrix?

Regulating cell differentiation

Which of the following correctly identifies the nucleus of this cell?

2 The nucleus, which is enclosed in the nuclear membrane, contains the cell's genetic material. The dark circular region within the nucleus is known as the nucleolus which is the site where new ribosomes are assembled.

A pathogen is ingested by a white blood cell. How might a lysosome assist in getting rid of the pathogen?

A lysosome can fuse to the pathogen once it has been engulfed in a vesicle, breaking it down with digestive enzymes. First, a vesicle is formed around the pathogen. The pathogen then fuses with a lysosome, forming a combined compartment where digestive enzymes can destroy the pathogen.

Which of the following is true regarding the cell theory? Choose all answers that apply:

All living organisms are made of one or more cells. Cells are the basic units of life.

Desmosomes are junctions that attach one cell to its neighbor, allowing tissues, like skin, to stretch without breaking. Which of the following proteins attach desmosomes to one another?

Cadherins Cadherins are the specialized adhesion proteins found in desmosomes. They are found on cell membranes, and work to "pin" adjacent cells together. This enables tissues, like cardiac muscle, to stretch without breaking.

Which of the following statements best identifies these two cells?

Cell X is a prokaryotic cell and Cell Y is a eukaryotic cell.

Which of the following choices correctly describes the composition of the cell membrane?

Contains lipids and proteins The plasma membrane is made of lipids that form a phospholipid bilayer. It also contains proteins that help with transport and cellular communication.

The cell theory is based on three major premises: -Cells are the basic units of life. -Each cell must come from a preexisting cell. -All living things are made up of cells. Which of the following discoveries was the last to be made?

Each cell must come from a preexisting cell. Scientists knew that cells existed and composed living things, but they were unsure about where cells came from. It wasn't until the 1850s that scientists uncovered that cells cannot arise spontaneously, but they must come from other cells.

Which of the following statements best describes eukaryote chromosomes compared to prokaryote chromosomes?

Eukaryotes generally have multiple linear chromosomes, while prokaryotes have a single-stranded circular chromosome. Eukaryotes, which are much more complex, contain multiple linear chromosomes that are bundled and stored in a membrane-bound nucleus. Prokaryotes have a single circular chromosome that is found in the central region of the cell.

A single prokaryotic cell can divide several times in an hour. Most eukaryotic cells cannot divide this quickly. Which of the following statements best explains this difference?

Eukaryotic cells are more structurally complex than prokaryotic cells.

Which of the following statements is true regarding gap junctions?

Gap junctions form when connexons align in adjacent animal cells to form a channel.

What type of microscope would be most effective for studying a living cell?

Light microscope In a light microscope, visible light passes through the specimen and is bent through the lens system, allowing the user to see a magnified image. Light microscopes can often be used on living cells to see them carrying out their normal behaviors.

Match the following cytoskeletal proteins with their functions.

Microfilaments Aid in cell movement and transport of vesicles Intermediate filaments Bear tension and maintain cell shape Microtubules Help the cell resist compression forces

What is the primary function of the rough endoplasmic reticulum (ER)?

Modifying proteins

Alonte is viewing a cell under a microscope. The presence of which of the following cell structures would tell him that the cell is eukaryotic?

Nucleus Only eukaryotes have a membrane-bound nucleus, which directs cellular functions and stores genetic information.

Which of the following statements correctly identifies the name and function of the cell structure labeled X?

Nucleus - stores genetic material

What is the function of organelle X?

Organelle X is where ATP is synthesized.

Based on the diagrams, which organism(s) are eukaryotic and why?

Organisms 1 and 2 only, because both have a nucleus. Organisms 1 and 2 have nuclei, which are characteristic of eukaryotic organisms. Organism 3 does not have a nucleus, suggesting that it is prokaryotic.

A cell has a mutation that makes it unable to appropriately synthesize proteins. Which organelle's function is likely to be impaired by this mutation?

Ribosomes Since ribosomes are responsible for the synthesis of proteins, it is likely that this mutation affects the ribosomes in the cell, rendering them unable to perform their normal functions.

Which scientists played a role in developing the cell theory? Choose all answers that apply:

Robert Remak Robert Hooke Theodor Schwann Matthias Schleiden

Which of the following is true regarding the rough endoplasmic reticulum (ER) and the smooth endoplasmic reticulum?

Rough ER: Modifies proteins to be used in cellular membranes Contains ribosomes on its surface Smooth ER: Synthesizes carbohydrates and steroid hormones Aids in detoxification of medications and poisons

Which of the following choices describes a function of the plasma membrane?

Separating the interior of the cell and the exterior of the cell Controlling the passage of various molecules Receiving cell signals

What is the main function of cytoplasm in a cell?

Suspending cellular structures and providing a place for cellular functions to take place

Which of the following correctly describes the structure and function of the cell wall in plants?

The cell wall is composed mainly of cellulose. It supports the cell, allowing it to maintain a rigid shape.

A scientist views a unicellular organism called a euglena under a microscope. Based on the diagram, what type of organism is the euglena and why?

The euglena is eukaryotic, because it has a nucleus.

A scientist observes a new organism through a microscope. Which of the following observations tells her that the organism is eukaryotic?

The organism has a membrane bound nucleus.

A scientist studying aquatic life discovers a new organism. He studies it under the microscope and draws a diagram of what he sees. Which of the following best describes the newly discovered organism?

The organism is eukaryotic, because it has a nucleus.

Which of the following statements best describes the organism below?

The organism is eukaryotic, because it has membrane-bound organelles.

Which of the following best describes the organism seen below?

The organism is prokaryotic, because it does not contain membrane-bound organelles.

Imarie uses a microscope to study different prokaryotic and eukaryotic organisms. Which of the following statements describes how the prokaryotic cells appear compared to the eukaryotic cells?

The prokaryotic cells are much smaller than the eukaryotic cells. Prokaryotic cells are much smaller than eukaryotic cells.

Part of the membrane of the Golgi pinches off and moves away in the form of a vesicle. Which of the following is true for this process?

The vesicles often deliver proteins to other areas in the cell or outside of the cell membrane. The Golgi apparatus packages modified proteins into vesicles that bud from the Golgi. Many of these vesicles deliver their contents to other parts of the cell where they will be used, while others are secreted outside of the cell.

Which of the following statements regarding chloroplasts is false?

Thylakoids are pigments found within chloroplasts that give plants their green color. Chlorophyll is the pigment that gives plants their green color. Chlorophyll is found within the thylakoid membrane.

Which of the following junctions form a watertight seal between neighboring cells?

Tight junction Tight junctions prevent liquid from seeping between cells. They allow a layer of cells to act as an impermeable barrier. One example of this is the bladder: the tight junctions between the cells lining your bladder prevent urine from leaking through to the extracellular space.

A team of scientists is studying detailed internal structures of a newly discovered cellular organism. What type of microscopy tool should the scientists use in order to observe these structures?

Transmission electron microscope

Trichodina is a eukaryotic organism that attaches itself to fish and eats bacteria. Which of the following features makes Trichodina different from all prokaryotes?

Trichodina has a nucleus. Only eukaryotes have a membrane-bound nucleus, which directs cellular functions and stores genetic information.

List the following microscopic items from smallest (top) to largest (bottom).

Water Molecule Hemoglobin Influenza Virus Skin Cell Grain of Salt