Chapter 28 - Being Multicellular Flashcards Preview

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Flashcards in Chapter 28 - Being Multicellular Deck (50):
1

Examples of organisms with macroscopic bodies and distinct tissue types can be found among both the prokaryotes and the eukaryotes.

False

2

Which of the following explains why bulk flow allows an organism to attain a larger body size?

Bulk flow allows nutrients to be transported over greater distances, rapid communication between different parts of the body, oxygen to reach interior cells that are located far from the surface of the body and allows waste products to be removed more efficiently.

3

Cell-signaling molecules are generally which type of macromolecule?

protein

4

What happens during gastrulation?

Cells migrate to form a layered structure.

5

Complex multicellular organisms did not succeed by doing the same thing as simpler eukaryotes.

true

6

Simple multicellular organisms show which of the following characteristics?

adhesion of cells
little signaling between cells
little differentiation of specialized cell types
little transfer of resources between cells

7

Which of the following cell adhesion molecules can be found in all complex multicellular organisms?

Neither cadherins, integrins or pectins

8

All plant cells except eggs and sperm are surrounded by cell walls.

True

9

Which of the following represents the correct order of evolution of requirements for complex multicellularity in animals?

adhesion, cell signaling, gap junctions, bulk flow

10

Which of the following statements about the organization of complex multicellular organisms is false?

Exterior cells are highly differentiated whereas interior cells are not differentiated.

11

Which of the following statements about diffusion is false?

It transports materials actively, powered by ATP.

12

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

Individual cells must retain a full range of functions, including reproduction.

13

Individual cells must retain a full range of functions, including reproduction.

blastula

14

While analyzing a sample of pond water, you discover a new organism whose body is composed of multiple cells. Upon closer inspection, you are able to determine that the individual cells are highly differentiated and organized into distinct interior and exterior tissue layers. Which of the following best describes the organization of this organism?

complex multicellular

15

Bulk flow is completely independent of diffusion; diffusion does not occur anywhere in the body of an organism that demonstrates bulk flow.

False

16

Which of the following cell adhesion molecules are found in animal tissues?

cadherins and integrins

17

During animal development, a fertilized egg divides to form a ball of undifferentiated cells called a:

blastula

18

Which of the following statements contrasting simple and complex multicellularity is true?

Complex multicellular organisms show a large degree of cellular differentiation, whereas simple multicellular organisms show little differentiation into specialized cell types.

19

Which of the following statements are true regarding sponges?

The structure of sponges—especially the pores and canals—allows sponges to achieve sizes of up to a meter (or more).

20

Which of the following is not involved in plant development?

active migration of cells

21

Which of the following statements about oxygen is false?

Oxygen is the only potential electron acceptor available on Earth's surface.

22

Diffusion is best defined as:

the random motion of individual molecules, with net movement from areas of higher concentration to areas of lower concentration.

23

Which of the following statements about the evolution of complex multicellularity is true?

Complex multicellularity evolved independently at least six times in different groups of organisms.

24

If animals were unable to produce pectin, what effect would this have on their epithelial tissues?

It would have no effect on epithelial tissue structure or function.

25

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:

plant cells on one side of the stem will elongate

26

Which of the following traits of complex multicellular organisms is also shared by some simple multicellular organisms, but not by single-celled organisms?

plasmodesmata

27

Which of the following statements regarding a simple multicellular organism is true?

If a single cell is removed from a simple multicellular organism, it may be able to reproduce on its own.

28

Which of the following statements about cell signaling is correct?

Signaling pathways and the molecules involved (e.g., kinases) evolved before the evolutionary split between plants and animals and thus are similar in the two groups.

29

In animals, fungi, and plants, bulk flow is always an active and ATP-expensive process. This is best evidenced by the need for a heart to beat in order for bulk flow to occur in animals.

False

30

Which of the following statements is true regarding bulk flow in both animals and plants?

Bulk flow is responsible for the movement of nutrients and hormones in both animals and plants.

31

Which of the following statements about adhesion molecules is false?

Cadherins and pectins are both transmembrane proteins.

32

Which of the following statements about the evolution of animal cell adhesion molecules is true?

Animal cell adhesion molecules evolved from protein families that originally performed other functions.

33

The passive movement of ions or molecules from a point of high concentration to a point of low concentration is known as:

diffusion

34

Which of the following statements concerning complex multicellular organisms is TRUE?

Bulk flow systems move substances faster than simple diffusion.

35

In humans and many other animals, what organ system is involved in bulk transport of nutrients, oxygen, and signaling molecules?

circulatory system

36

Which of the following molecules help maintain cell–cell adhesions in plants?

pectins

37

Which of the following is TRUE of plasmodesmata?

They are holes in the cell wall through which the plasma membrane and endoplasmic reticulum of adjacent cells are connected.

38

An inhibitor of mitosis would most likely have the greatest effect on the _____ of a plant.

meristems

39

In which order were the key features of complex multicellularity likely to have appeared?

cell adhesion, cell communication, regulated growth and development

40

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

Multicellularity helps organisms avoid predation.

41

Cells in the interior of complex multicellular organisms are able to respond to environmental signals through:

receptors for signals sent from exterior cells that relay information about environmental changes.

42

Which of the following is an adaptation shared by virtually all complex multicellular organisms that allows the organisms to receive the oxygen and nutrients they need?

amplification of surface areas

43

The evolution from simple multicellular organisms to complex multicellular organisms required:

the development of a system that enabled bulk flow.

44

What is the main limitation on cell size?

diffusion

45

The vegetative cells of the simple multicellular organism Volvox function in:

photosynthesis

46

What structures are used in animal cells to move molecules between cells?

gap junctions

47

An undifferentiated cell in animals that can develop into any of several differentiated cell types is called a:

stem cell

48

Cadherins are transmembrane proteins that function in:

cell–cell adhesion

49

Unlike plant cells, animal cells move during development. Which of the following terms describes the reorganization of undifferentiated cells that results in the formation of an embryonic structure with multiple layers?

gastrula formation

50

The discovery that single-celled sister groups of animals synthesize proteins known to play roles in animal development tells us that:

the single-celled sister groups use the proteins in question for functions other than multicellular development