Ch. 1 Flashcards

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1
Q

All cells require oxygen to live.

A

false

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2
Q

In what way are all cells alike?

A

They store their genetic instructions in DNA.

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3
Q

How long ago is it estimated that the common ancestor for all of life existed?

A

Between 3.5 and 3.8 billion years ago

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4
Q

Genetic change followed by selection are the fundamentals of what process?

A

Evolution

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5
Q

Which statement is NOT true about the differences between liver cells and kidney cells from the same animal?

A

The different cells have different DNA.

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6
Q

Which statement IS true about the differences between liver cells and kidney cells from the same animal?

A
  • The different cells express different genes.

- he different cells have different roles in the body.

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7
Q

What is the cell theory?

A

All cells are formed by the division of preexisting cells.

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8
Q

Which of these structures cannot be resolved with a conventional light microscope?

A

Ribosome

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9
Q

Which of these structures CAN be resolved with a conventional light microscope?

A
  • Mitochondrion
  • Bacterium
  • Nucleus
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10
Q

An individual ribosome can be seen with a fluorescence microscope.

A

True

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11
Q

Individual atoms can be seen with an electron microscope.

A

False

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12
Q

.What do eukaryotic cells have that prokaryotes lack?

A

A nucleus and other internal organelles

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13
Q

.Which of the following are prokaryotes?

A

Archaea and bacteria

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14
Q

At a molecular level, the members of the two domains of prokaryotes–the archaea and bacteria–differ as much from each other as either does from the eukaryotes.

A

True

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15
Q

The DNA in the nucleus of eukaryotic cells is separated from the cytoplasm by the:

A

nuclear envelope.

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16
Q

Which statement is NOT true of mitochondria?

A

Mitochondria are not present in plant cells.

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17
Q

Which statement IS true of mitochondria?

A
  • Mitochondria have an inner and outer membrane.
  • Mitochondria contain their own DNA.
  • Mitochondria are thought to have originated from bacteria.
  • Mitochondria generate chemical energy for the cell.
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18
Q

.Which statement is NOT true of chloroplasts?

A

Chloroplasts are present in essentially all eukaryotic cells.

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19
Q

.Which statement IS true of chloroplasts?

A
  • Each has an internal stack of membranes and is enclosed by two membranes.
  • Chloroplasts contain their own DNA.
  • Chloroplasts are thought to have originated from bacteria.
  • Chloroplasts produce food molecules and generate oxygen.
20
Q

Which of the following organelles is an irregular maze of interconnected spaces enclosed by a membrane that functions as the site where most cell membrane components, as well as materials destined for export from the cell, are made?

A

The endoplasmic reticulum

21
Q

Which of the following organelles is a stack of flattened membrane-enclosed sacs, functioning in receiving and often chemically modifying the molecules made in the endoplasmic reticulum, and then directing them to the exterior of the cell or to various locations inside the cell?

A

The Golgi apparatus

22
Q

Which of the following organelles is a small, irregularly shaped organelle in which intracellular digestion occurs?

A

Lysosome

23
Q

What mediates the exchange of materials between the endoplasmic reticulum, Golgi apparatus, the lysosomes, and the outside of the cell?

A

Vesicles

24
Q

What is the name of the process by which eukaryotic cells engulf material captured from an external medium?

A

Endocytosis

25
Q

The largest single compartment in most cells is:

A

the cytosol.

26
Q

Which of these is NOT part of the cytoskeleton?

A

the cytosol.

27
Q

Which of these IS part of the cytoskeleton?

A
  • Actin filaments
  • Microtubules
  • Intermediate filaments
28
Q

What role is NOT performed by the cytoskeleton?

A

Generating chemical energy

29
Q

What role IS performed by the cytoskeleton?

A
  • Pulling duplicated chromosomes to opposite poles in dividing cells
  • Transporting organelles and molecules from one place to another in the cytoplasm
  • Controlling cell shape and cell movement
30
Q

In plant cells, a tough cell wall takes the place of a cytoskeleton.

A

False

31
Q

The cytoskeleton is one of the few permanent fixtures in the cell.

A

False

32
Q

Which organelle’s ancestor was likely engulfed by primitive eukaryotes to help the cell survive in an oxygen-rich atmosphere?

A

Mitochondrion

33
Q

Which statement is NOT true of E. coli?

A

E. coli is a model eukaryote.

34
Q

Which statement IS true of E. coli?

A
  • E. coli is small, rod-shaped cell.
  • E. colican be grown in the laboratory
  • E. coli normally lives in the gut of humans and other vertebrates.
35
Q

What is NOT a reason scientists study yeast?

A

It lacks a nucleus so it is easy to genetically manipulate.

36
Q

What IS a reason scientists study yeast?

A
  • It carries out all the basic tasks a eukaryotic cell must perform.
  • It is as closely related to animals as it is plants.
  • It reproduces rapidly in the lab.
37
Q

Which of the following is a model plant used by scientists?

A

Arabidopsis

38
Q

Early studies of Drosophila melanogaster showed that:

A

genes are carried on chromosomes.

39
Q

Which of the following is frequently studied as a model vertebrate?

A

Zebrafish

40
Q

Human cells are capable of surviving in a culture dish.

A

True

41
Q

.If two genes from different organisms have closely similar DNA sequences, it is highly probable that both genes descended from a common ancestral gene.

A

True

42
Q

Which term describes genes (and gene products) related by a common ancestral gene?

A

Homologous

43
Q

.DNA contains sequences that:

A
  • code for proteins.
  • code for functional RNA molecules.
  • are seemingly dispensable.
  • regulate gene activity
44
Q

Eukaryotic cells contain multiple membrane-enclosed organelles. How might have this arrangement evolved? What evidence supports your theory?

A

One theory is that an ancestral eukaryotic cell was a predator that fed by capturing other cells. Eukaryotic cells are large and have a flexible membrane and cytoskeleton, characteristics that would allow them to chase down and devour other cells. The nuclear compartment may have evolved to keep the DNA segregated from the prey that this primitive eukaryotic cell engulfed. This eukaryotic cell may also have engulfed free-living, oxygen-consuming bacteria that later evolved into the mitochondria of modern eukaryotic cells. An early eukaryotic cell could similarly have engulfed photosynthetic bacteria that later evolved into chloroplast. An example of this predatory behavior is observed in modern protozoans, which are free-living single-celled eukaryotes that can prey upon and swallow other cells whole.

45
Q

Name three membrane-enclosed organelles and describe their respective roles in the cell.

A

The endoplasmic reticulum, or ER, is the site where most cell membrane components, as well as materials destined for export from the cell, are made.
The Golgi apparatus is involved in the synthesis and packaging of molecules destined for export from the cell. It is also involved in the routing and transport of newly synthesized proteins to the correct cellular compartment.
Lysosomes are the organelles in which intracellular digestion occurs. They release nutrients from food and break down unwanted molecules.
Peroxisomes are vesicles that provide an enclosed environment in which hydrogen peroxide inactivates toxins.
Endosomes are vesicles that sort and transport materials ingested by endocytosis.