Question 1

You are asked to determine whether an unknown tissue specimen comes from a plant or an animal. Closer inspection with an electron microscope reveals that the cells are connected by small openings lined by extensions of the cell membrane and containing tubules connecting the endomembrane systems of adjacent cells. Which of the following conclusions can you draw from your observations?

Accepted Answer

A)  The openings are plasmodesmata, so the tissue must come from a plant.
B)  The openings are plasmodesmata, so the tissue must come from an animal.
C)  The openings are gap junctions, so the tissue must come from a plant.
D)  The openings are gap junctions, so the tissue must come from an animal.
E)  The openings could be either gap junctions or plasmodesmata, so it cannot be determined whether the tissue came from a plant or an animal.F) B) and E)
G) B) and C)

Question 2

Some species of choanoflagellates can form multicellular structures in the presence of their desired food bacterium; however, not all choanoflagellate species will form multicellular structures. Multicellularity is induced in some forms of choanoflagellates because of signals released by the bacterium. This variation in the ability to develop multicellular structures is MOST likely the result of:

Accepted Answer

A)  changes in patterns of gene expression resulting in multicellular aggregations in some, but not all choanoflagellates.
B)  changes in the pattern of integrin expression in choaoflagellates forming multicellular aggregations.
C)  the evolution of genes for cell-adhesion molecules in only in choanoflagellates that form multicellular aggregations.
D)  the evolution of differential responses to environmental signals.E) A) and C)
F) A) and B)

Question 3

You may have noticed that a plant placed on a windowsill will eventually bend toward a light source. This is likely due to the fact that, in response to a light source:

Accepted Answer

A)  plant cells will move from one side of a stem to the opposite side.
B)  plant cells on one side of the stem will elongate.
C)  all the cells of a plant's meristem will differentiate.
D)  the cell walls of plant cells will break down.E) B) and C)
F) A) and B)

Question 4

A human gastrula is composed of three cell layers stacked on top of one another (like the layers of a sandwich). As the early cells within human embryos are incapable of migration, this tri-laminar disc is the result of mitotic cell division and not the active movement of cells.

Accepted Answer

A) True 
 B)False

Question 5

Which of the following statements about plant and animal development is FALSE?

Accepted Answer

A)  Cell division occurs in discrete regions within the plant body, but tissue differentiation occurs throughout the plant body.
B)  Cell differentiation and growth occurs throughout the developing animal body.
C)  Animal cells move during development, whereas plant cells do not.
D)  In both plants and animals, signaling molecules induce cell differentiation.
E)  Animal embryos pass through a gastrula stage, whereas plant embryos do not.F) B) and E)
G) A) and B)

Question 6

Which of the following is a term describing a multinucleated organism made up of a single cell?

Accepted Answer

A)  colonial
B)  multicellular
C)  differentiated
D)  coenocyticE) A) and B)
F) B) and C)

Question 7

The oxygen needed for respiration moves from the lungs and into capillaries by simple diffusion. Once in the capillaries, what molecule or other component of blood is responsible for transporting oxygen in the circulatory system?

Accepted Answer

A)  There is no transport molecule; oxygen remains free in the blood.
B)  white blood cells
C)  hemoglobin
D)  cadherinsE) A) and B)
F) C) and D)

Question 8

Cell-cell signaling is limited to complex multicellular organisms composed of organs and organ systems.

Accepted Answer

A) True 
 B)False

Question 9

Which of the following describes the anatomy of a coenocytic organism?

Accepted Answer

A)  The body is made of a large cell with many nuclei.
B)  The body cells are organized into well-defined tissue layers.
C)  The body cells are organized into branching filaments.
D)  The body is made up of several different types of highly specialized cells.
E)  The body is a hollow ball of flagellated cells.F) All of the above
G) A) and E)

Question 10

If all animal cellsboth embryonic and adultsuddenly possessed cell walls, which of the following processes would be negatively affected?

Accepted Answer

A)  the movement of materials through the intestines
B)  the ability of animals to move their limbs (i.e., muscle contraction) 
C)  the development of the gastrula during embryogenesis
D)  the ability of animal hearts to pump blood
E)  All of these choices are correct.F) A) and D)
G) A) and B)

Question 11

In complex multicellular organisms, bulk flow is an important physiologic character. Why is bulk flow a necessary condition of complex multicellularity?

Accepted Answer

A)  Complex multicellularity reflects cell adhesion between cells, and this cannot happen without bulk flow of signaling molecules from the environment.
B)  Organisms exhibiting complex multicellularity are large and have cells/tissues that are not in contact with their environment. Systems that can overcome the limits of diffusion must occur for basic physiologic processes to occur.
C)  Bulk flow is necessary to move large amounts of liquid through the organism depending on physiologic needs. The tissues can all receive necessary nutrients from the environment, but bulk flow speeds the rate of diffusion.
D)  Complex multicellularity is related to the increase in oxygen in the environment. Because bulk flow systems are only related to the delivery of oxygen to tissues, higher environmental oxygen selected for individuals with bulk flow systems.E) None of the above
F) A) and B)

Question 12

What happens during gastrulation?

Accepted Answer

A)  Cells migrate to form a layered structure.
B)  A fertilized egg divides mitotically to form a ball of cells.
C)  A gastrula is transformed into a blastula.
D)  The embryo divides into distinct zones of cell division, cell expansion, and cell differentiation.
E)  All of these choices are correct.F) B) and C)
G) A) and C)

Question 13

Which of the following is NOT a general requirement for complex multicellular life?

Accepted Answer

A)  Individual cells must retain a full range of functions, including reproduction.
B)  Cells must stick together.
C)  Cells must communicate with one another.
D)  Cells must participate in a network of genetic interactions that regulate cell division.
E)  All of these choices are correct.F) All of the above
G) B) and E)

Question 14

Which one of the following is a selective advantage of simple multicellularity over single-celled organisms?

Accepted Answer

A)  Multicellularity helps organisms avoid predation.
B)  Multicellularity results in fundamental changes in metabolic processes.
C)  Multicellularity helps organisms utilize more food sources.
D)  Multicellularity helps organisms enhance efficiency of reproduction.E) A) and C)
F) B) and C)

Question 15

The ability of cells to adhere to one another is fundamental to multicellularity.

Accepted Answer

A) True 
 B)False

Question 16

Which of the following is TRUE of plasmodesmata?

Accepted Answer

A)  They are holes in the cell wall through which the plasma membrane and endoplasmic reticulum of adjacent cells are connected.
B)  They are channels in the plasma membrane of plant cells made of transmembrane proteins that allow ions and small molecules to pass between adjacent cells.
C)  They are channels in the plasma membrane of animal cells made of transmembrane proteins that allow ions and small molecules to pass between adjacent cells.
D)  They provide points of structural support between adjacent plant cells.
E)  They provide points of structural support between adjacent animal cells.F) A) and E)
G) D) and E)

Question 17

A researcher is looking through a microscope at a petri dish full of mouse embryos. These embryos appear as balls with no indentations along their surfaces. These embryos are MOST likely:

Accepted Answer

A)  mouse gastrulas.
B)  mouse blastulas.
C)  mouse meristems.
D)  mouse fetuses.
E)  mouse colonies.F) A) and B)
G) C) and D)

Question 18

A jellyfish relies on diffusion to provide oxygen to its body cells, and yet it is much larger than the 1 cm limit imposed by diffusion. How can it be so thick and still meet its metabolic demands by diffusion alone?

Accepted Answer

A)  Much of the thickness of a jellyfish consists of metabolically inert materials that do not require oxygen.
B)  Jellyfish have specialized tubular cells that facilitate the movement of oxygen throughout the body.
C)  The layers of metabolically active tissue are very thick and highly folded, which provides a large surface area for diffusion.
D)  Jellyfish maintain a very large concentration gradient for oxygen across their body tissues.
E)  Water makes up most of the body of a jellyfish, and oxygen diffuses more rapidly in water than in tissues.F) B) and D)
G) A) and E)

Question 19

Undifferentiated cells of plants are MOST likely to be present in which of the following tissues?

Accepted Answer

A)  leaves
B)  transport systems (xylem and phloem) 
C)  root tips
D)  flowersE) None of the above
F) All of the above

Question 20

While observing a new species of seaweed under the microscope, you determine that the entire organism is one large cell containing several nuclei. Which of the following BEST describes the organization of this organism?

Accepted Answer

A)  coenocytic
B)  complex multicellular
C)  simple multicellular
D)  filamentous
E)  eukaryoticF) A) and E)
G) B) and E)

Exam 28: Being Multicellular

The oxygen needed for respiration moves from the lungs and into capillaries by simple diffusion. Once in the capillaries, what molecule or other component of blood is responsible for transporting oxygen in the circulatory system?

Correct Answer
verified

What happens during gastrulation?

Correct Answer
verified

While observing a new species of seaweed under the microscope, you determine that the entire organism is one large cell containing several nuclei. Which of the following BEST describes the organization of this organism?

Correct Answer
verified

A human gastrula is composed of three cell layers stacked on top of one another (like the layers of a sandwich). As the early cells within human embryos are incapable of migration, this tri-laminar disc is the result of mitotic cell division and not the active movement of cells.

Correct Answer
verified

Which of the following describes the anatomy of a coenocytic organism?

Correct Answer
verified

You may have noticed that a plant placed on a windowsill will eventually bend toward a light source. This is likely due to the fact that, in response to a light source:

Correct Answer
verified

Undifferentiated cells of plants are MOST likely to be present in which of the following tissues?

Correct Answer
verified

A researcher is looking through a microscope at a petri dish full of mouse embryos. These embryos appear as balls with no indentations along their surfaces. These embryos are MOST likely:

Correct Answer
verified

Cell-cell signaling is limited to complex multicellular organisms composed of organs and organ systems.

Correct Answer
verified

Which of the following is TRUE of plasmodesmata?

Correct Answer
verified

Correct Answer
verified

If all animal cellsboth embryonic and adultsuddenly possessed cell walls, which of the following processes would be negatively affected?

Correct Answer
verified

In complex multicellular organisms, bulk flow is an important physiologic character. Why is bulk flow a necessary condition of complex multicellularity?

Correct Answer
verified

Which of the following statements about plant and animal development is FALSE?

Correct Answer
verified

The ability of cells to adhere to one another is fundamental to multicellularity.

Correct Answer
verified

Correct Answer
verified

Which of the following is a term describing a multinucleated organism made up of a single cell?

Correct Answer
verified

A jellyfish relies on diffusion to provide oxygen to its body cells, and yet it is much larger than the 1 cm limit imposed by diffusion. How can it be so thick and still meet its metabolic demands by diffusion alone?

Correct Answer
verified

Which one of the following is a selective advantage of simple multicellularity over single-celled organisms?

Correct Answer
verified

Which of the following is NOT a general requirement for complex multicellular life?

Correct Answer
verified

Exam 28: Being Multicellular

The oxygen needed for respiration moves from the lungs and into capillaries by simple diffusion. Once in the capillaries, what molecule or other component of blood is responsible for transporting oxygen in the circulatory system?

Correct AnswerverifiedShow Answer

What happens during gastrulation?

Correct AnswerverifiedShow Answer

While observing a new species of seaweed under the microscope, you determine that the entire organism is one large cell containing several nuclei. Which of the following BEST describes the organization of this organism?

Correct AnswerverifiedShow Answer

A human gastrula is composed of three cell layers stacked on top of one another (like the layers of a sandwich). As the early cells within human embryos are incapable of migration, this tri-laminar disc is the result of mitotic cell division and not the active movement of cells.

Correct AnswerverifiedShow Answer

Which of the following describes the anatomy of a coenocytic organism?

Correct AnswerverifiedShow Answer

You may have noticed that a plant placed on a windowsill will eventually bend toward a light source. This is likely due to the fact that, in response to a light source:

Correct AnswerverifiedShow Answer

Undifferentiated cells of plants are MOST likely to be present in which of the following tissues?

Correct AnswerverifiedShow Answer

A researcher is looking through a microscope at a petri dish full of mouse embryos. These embryos appear as balls with no indentations along their surfaces. These embryos are MOST likely:

Correct AnswerverifiedShow Answer

Cell-cell signaling is limited to complex multicellular organisms composed of organs and organ systems.

Correct AnswerverifiedShow Answer

Which of the following is TRUE of plasmodesmata?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

If all animal cellsboth embryonic and adultsuddenly possessed cell walls, which of the following processes would be negatively affected?

Correct AnswerverifiedShow Answer

In complex multicellular organisms, bulk flow is an important physiologic character. Why is bulk flow a necessary condition of complex multicellularity?

Correct AnswerverifiedShow Answer

Which of the following statements about plant and animal development is FALSE?

Correct AnswerverifiedShow Answer

The ability of cells to adhere to one another is fundamental to multicellularity.

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Which of the following is a term describing a multinucleated organism made up of a single cell?

Correct AnswerverifiedShow Answer

A jellyfish relies on diffusion to provide oxygen to its body cells, and yet it is much larger than the 1 cm limit imposed by diffusion. How can it be so thick and still meet its metabolic demands by diffusion alone?

Correct AnswerverifiedShow Answer

Which one of the following is a selective advantage of simple multicellularity over single-celled organisms?

Correct AnswerverifiedShow Answer

Which of the following is NOT a general requirement for complex multicellular life?

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified