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Life: The Science of Biology 11th Edition > Chapter 26. The Origin and Diversification of Eukaryotes > Flashcards

Chapter 26. The Origin and Diversification of Eukaryotes Flashcards

1
Q

What are the four main groups of eukaryotic organisms?

A

Animals, Fungi, Plants, and Protists

26.1 Eukaryotes Acquired Features from Both Archaea and Bacteria

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2
Q

What are protists?

A

Any eukaryotic organism that is not an animal, fungi or plant is classified as a protist. Protists are usually unicellular.

26.1 Eukaryotes Acquired Features from Both Archaea and Bacteria

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3
Q

Eukaryotic cells derived chloroplasts and mitochondria from which bacterial organisms

A

Chloroplasts from cyanobacteria and mitochondria from proteobacteria

26.1 Eukaryotes Acquired Features from Both Archaea and Bacteria

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4
Q

From the phylogenetic tree shown below which other domain of life (bacteria and archaea) is eukaryotes more closely related to?

A

Eukaryotes are more closely related to archaea than bacteria. They are especially related to archaea called Lokiarchaeota.

“eukaryotes are a specialized group of archaea that acquired a cell nucleus.” quote found on page 556 of Life 11th edition.

26.1 Eukaryotes Acquired Features from Both Archaea and Bacteria

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5
Q

Name the process that explains how eukaryotes got mitochondria and chloroplasts from Bacteria.

A

Endosymbiosis

26.1 Eukaryotes Acquired Features from Both Archaea and Bacteria

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6
Q

Name the important events that lead to the evolution of the modern eukaryotic cell

A
  • The evolution of a flexible cell surface
  • The evolution of a cytoskeleton
  • The evolution of a nuclear envelope enclosing a genome organized into chromosomes
  • The evolution of digestive vacuoles
  • Receiving mitochondria and chloroplasts through endosymbiosis of bacteria

26.1 Eukaryotes Acquired Features from Both Archaea and Bacteria

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7
Q

What are the advantages of a flexible cell surface?

A

A flexible cell surface (membrane) allows the cell surface to fold inward. A cell surface that folds inward has two main benefits.

  1. It means that it can increase its suface area by folding inward allowing the cell to grow in size and hence volume without comprising too much, the rate substances move in and out of the cell.
  2. A cell that has a flexible cell surface can undergo endocytosis.

Great video to watch on surface area to volume ratio of cells: https://youtu.be/FK9xHry877U

A good video to watch about endocytosis: https://youtu.be/QspmZf_yWyU

26.1 Eukaryotes Acquired Features from Both Archaea and Bacteria

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8
Q

What is the evidence that eukaryotes acquired mitochondria and chloroplasts from endosymbiosis?

A

The sequence of nucleotides in rRNA genes found in chloroplasts and mitochondria are more similar to the sequence of nucleotides in the same rRNA genes found in present-day Cyanobacteria (Chlorobium) and Proteobacteria (E.coli) than in present-day eukaryotes.

26.1 Eukaryotes Acquired Features from Both Archaea and Bacteria

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9
Q

What other events important to the evolution of eukaryotes?

A
  • The development of a more complex cytoskeleton
  • The formation of ribosome-studded internal membranes, some of which surrounded the DNA
  • The enclosure of the cell’s DNA in a nucleus
  • The formation of a flagellum from microtubules of the cytoskeleton
  • The evolution of digestive vacuoles

26.1 Eukaryotes Acquired Features from Both Archaea and Bacteria

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10
Q

How did digestive vacuoles evolve to become lysosomes

A

Using enzymes from the early endoplasmic reticulum

26.1 Eukaryotes Acquired Features from Both Archaea and Bacteria

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11
Q

Is the presence of cytoskeletons restricted only to eukaryotes?

A

no - cytoskeletons are also found in prokaryotes which tells us that simple cytoskeletons evolved before the specialized group of archaeans called eukaryotes evolved.

26.1 Eukaryotes Acquired Features from Both Archaea and Bacteria

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12
Q

The cytoskeletons of prokaryotes or eukaryotes are more sophisticated?

A

The cytoskeletons of eukaryotes are more sophisticated than the cytoskeletons of prokaryotes.

26.1 Eukaryotes Acquired Features from Both Archaea and Bacteria

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13
Q

What does the cytoskeleton allow the eukaryotes to do?

A
  • Supports the cell
  • To control shape changes in eukaryotes
  • Move daughter chromosomes
  • Move materials from one region of the cell to another.
  • Has allowed some eukaryotes to develop flagellums

26.1 Eukaryotes Acquired Features from Both Archaea and Bacteria

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14
Q

Describe the theory of endosymbiosis

A

It proposes that certain organelles found in eukaryotic cells today are actually the descendants of ancient bacteria. These organelles were engulfed but not digested by ancient eukaryotes.

For example, an ancient eukaryotic cell engulfed (but not digested) an ancient proteobacterium and the engulfed proteobacterium evolved to become the mitochondria we see in eukaryotic cells today.

The other example is chloroplasts. An ancient eukaryotic cell engulfed (but not digested) an ancient cyanobacterium and the engulfed cyanobacterium evolved to become the chloroplasts we see in photosynthetic eukaryotic cells today.

26.1 Eukaryotes Acquired Features from Both Archaea and Bacteria

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15
Q

The event where an ancient eukaryotic cell engulfs a single ancient cyanobacterium is called _________

Primary/secondary/tertiary endosymbiosis

A

Primary endosymbiosis

26.1 Eukaryotes Acquired Features from Both Archaea and Bacteria

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16
Q

Are cyanobacteria gram-negative or gram-positive?

A

Cyanobacteria are gram-negative which means they have two phospholipid bilayers sandwiching a thin layer of peptidoglycan in its cell wall.

26.1 Eukaryotes Acquired Features from Both Archaea and Bacteria

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17
Q

If a eukaryote cell engulfs a cyanobacterium how many outer membranes would the cyanobacterium have.

A

There are three in total. The cyanobacterium is gram-negative so it has two membranes and the host eukaryotic cell gives one more membrane to the cyanobacterium during endocytosis. However, during evolutionary history, the cyanobacterium lost one of its three membranes.

26.1 Eukaryotes Acquired Features from Both Archaea and Bacteria

Animation: http://www.life11e.com/animation2601.html

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18
Q

The peptidoglycan layer of cyanobacteria has been lost from all groups of photosynthetic eukaryote except the ________

A

Glaucophytes

Animation: http://www.life11e.com/animation2601.html

26.1 Eukaryotes Acquired Features from Both Archaea and Bacteria

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19
Q

The single endosymbiotic event with one ancient eukaryotic cell engulfing one ancient cyanobacterium gave rise to the chloroplasts of the _________and _____ algae and also land plants since land plants evolved from a green algae ancestor. All other photosynthetic eukaryotes such as Euglenids got chloroplasts from an ancestral eukaryote that acquired a chloroplast from ________ or ________ endosymbiosis.

A

green; red; secondary; tertiary

26.1 Eukaryotes Acquired Features from Both Archaea and Bacteria

Animation: http://www.life11e.com/animation2601.html

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20
Q

Explain what tertiary and secondary endosymbiosis is

A

Secondary endosymbiosis - The process by which a eukaryotic cell engulfs a photosynthetic eukaryote that acquired its chloroplast by primary endosymbiosis.

Tertiary endosymbiosis - The process by which a eukaryotic cell engulfs a photosynthetic eukaryote that acquired its chloroplast by secondary endosymbiosis.

26.1 Eukaryotes Acquired Features from Both Archaea and Bacteria

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21
Q

Name the organism that got its chloroplast by tertiary endosymbiosis

A

Dinoflagellates

26.1 Eukaryotes Acquired Features from Both Archaea and Bacteria

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22
Q

Name the organism that got its chloroplast from secondary endosymbiosis

A

Euglenids

26.1 Eukaryotes Acquired Features from Both Archaea and Bacteria

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23
Q

What are the eight main groups of eukaryotes?

A
  1. Alveolates (protist)
  2. Stramenopiles (protist)
  3. Rhizarians (protist)
  4. Excavates (protist)
  5. Plants
  6. Amoebozoans (protist)
  7. Fungi
  8. Animals

26.2 Major Lineages of Eukaryotes Diversified in the Precambrian

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24
Q

What name is given to unicellular protists?

A

Microbial eukaryotes

26.2 Major Lineages of Eukaryotes Diversified in the Precambrian

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25
Q

Name the three groups that belong to the alveolate group.

A
  • Dinoflagellates
  • Apicomplexans
  • Ciliates

26.2 Major Lineages of Eukaryotes Diversified in the Precambrian

26
Q

What colour are the chloroplasts of Dinoflagellates?

A

Golden brown

26.2 Major Lineages of Eukaryotes Diversified in the Precambrian

27
Q

What are red tides?

A

Red tide is a phenomenon caused by algal blooms (large concentrations of aquatic microorganisms) caused by dinoflagellates that turn the colour of the water red or brown.

26.2 Major Lineages of Eukaryotes Diversified in the Precambrian

28
Q

All apicomplexans are parasitic/mutualistic

A

Parasitic

26.2 Major Lineages of Eukaryotes Diversified in the Precambrian

29
Q

Why are apicomplexans called apicomplexans?

A

That’s because apicomplexans have a collection of organelles that form the apical complex. The apical complex is found at the tip of the cell.

26.2 Major Lineages of Eukaryotes Diversified in the Precambrian

30
Q

Give the function of the apical complex and an example of the apical complex in action

A

The apical complex aids the apicomplexan invasion of its host’s (target cell’s) tissues.

For example, the apical complex helps plasmodium (the protist that causes malaria) entry into human body tissues after transmission by a mosquito.

26.2 Major Lineages of Eukaryotes Diversified in the Precambrian

31
Q

Another example of an apicomplexan is toxoplasma. Toxoplasma alternates between ______ and _______ to complete its life cycle. Rats infected with toxoplasma feel less afraid of cats and therefore become easy prey to the cats.

Answer choices for blanks dogs/cats; rats/mice

A

cats; rats

26.2 Major Lineages of Eukaryotes Diversified in the Precambrian

Good video on parasites: https://youtu.be/g09BQes-B7E

32
Q

What does heterotrophic mean?

A

It describes an organism that cannot make it’s on own food and must feed on animal and plant matter to obtain organic compounds and energy. All animals, fungi, protozoans and some bacteria are heterotrophic

26.2 Major Lineages of Eukaryotes Diversified in the Precambrian

33
Q

Why are the ciliates called the ciliates?

A

They possess many hairlike cilia which are shorter but identical to eukaryotic flagella.

26.2 Major Lineages of Eukaryotes Diversified in the Precambrian

34
Q

What is the defining character of ciliates?

A

They have two types of nuclei

26.2 Major Lineages of Eukaryotes Diversified in the Precambrian

35
Q

Which genus that belongs to the ciliate group exemplifies the complex structure and behavior of a ciliate

A

The paramecium genus

26.2 Major Lineages of Eukaryotes Diversified in the Precambrian

36
Q

Describe the pellicle of a paramecium

A

The pellicle covers the whole organism belonging to the paramecium genus and so could be called the outer membrane of the paramecium. The pellicle itself consists of closely packed alveoli that surround the base of the cilia. The pellicle also has defensive organelles called trichocysts (Try-coal-cysts). They shoot out like sharp darts when a microexplosion occurs in the paramecium.

26.2 Major Lineages of Eukaryotes Diversified in the Precambrian

37
Q

State was composes a pellicle in a paramecium

A
  • Trichocysts
  • Fibrils
  • Alveoli
  • Cilia

26.2 Major Lineages of Eukaryotes Diversified in the Precambrian

38
Q

Name some of the other organelles of the paramecium except the pellicle and composition of the pellicle

A
  • Anal pore
  • Contractile vesicle
  • Oral groove
  • Digestive vacuole
  • Micronuclei
  • Macronuclei

26.2 Major Lineages of Eukaryotes Diversified in the Precambrian

39
Q

What is the function of the micro and macronuclei of the paramecium?

A
  • Macronuclei - Controls all the of the Paramecium cell’s activities.
  • Micronuclei - Involved in genetic recombination

26.2 Major Lineages of Eukaryotes Diversified in the Precambrian

40
Q

Describe the movement of paramecium

A

It’s the cilia it posses that facilitates its motion. The cilia in paramecium can better control movement than flagella in other cells because it allows the paramecium cell to move forward and backward and move backward quickly.

26.2 Major Lineages of Eukaryotes Diversified in the Precambrian

41
Q

Explain what the contractile vacuoles do?

A

The excess water that enters the paramecium cell by osmosis collects in the contractile vacuole. The contractile vacuole then contracts to expel the excess water out of the cell.

26.2 Major Lineages of Eukaryotes Diversified in the Precambrian

42
Q

Describe the steps of digestion in a paramecium

A

Note: researchers dyed the yeast cells with a dye called congo red that is red when the pH is greater than or equal to 7. Lower than 7 and the dye turns green.

  1. A paramecium’s food like yeast cells moves through an opening in the paramecium called the oral groove.
  2. Once the yeast cells move to the bottom of the oral groove, a digestive vacuole forms around the yeast cells.
  3. The yeast cells in the digestive vacuole turn green indicating that inside the digestive vacuole is an acidic environment.
  4. Proteolytic enzymes (who work best at acidic pHs) help digest the yeast cells.
  5. The products of digestion of the yeast cells get absorbed by the cytosol of the paramecium through smaller vesicles that pinch off from the digestive vacuole. The smaller vesicles increase surface area causing faster absorption of digestion products by the cytosol.
  6. The digestive vacuole turns red in colour and all that remains in the vacuole is the waste (stained red). The vacuole fuses with the membrane expelling the waste out of the cell.

http: //www.life11e.com/animation2602.html
26. 2 Major Lineages of Eukaryotes Diversified in the Precambrian

43
Q

What the difference between the cytosol and cytoplasm of the cell?

A

Cytoplasm - The jelly-like fluid that fills the cell. It is made up of mostly salt and water.

Equation: Cytoplasm = Whole cell - Nucleus

Cytosol - The fluid in which organelles of the cell reside.

Equation: Cytosol = Whole cell - (Nuclus + Organelles)

Not found in 26.2 I was just curious

44
Q

What does “unicellular protists living in freshwater are hypertonic to their environment” mean?

A

It means that the protist cell must be hypertonic and its environment must be hypotonic.

26.2 Major Lineages of Eukaryotes Diversified in the Precambrian

45
Q

What does hypertonic, isotonic and hypotonic mean?

A

Hypertonic - Low concentration of water and a higher concentration of solutes.

Isotonic - equal concentration of solutes and water.

Hypotonic - high concentration of water and low concentration of solutes

26.2 Major Lineages of Eukaryotes Diversified in the Precambrian

46
Q

In which direction does water move during osmosis?

A

From areas of low solute concentration and high water concentration towards areas of high solute concentration and low water concentration.

26.2 Major Lineages of Eukaryotes Diversified in the Precambrian

47
Q

Are protists hypertonic compared to their environment or hypotonic compared to their environment?

A

Hypertonic. This means that there is a greater concentration of solutes and lower concentration of water compared to its outside environment. Therefore osmosis drives the movement of water molecules outside of the cell inside the cell.

26.2 Major Lineages of Eukaryotes Diversified in the Precambrian

48
Q

What three groups belong to the stramenopiles?

A

Brown algae, diatoms, and the oomycetes

26.2 Major Lineages of Eukaryotes Diversified in the Precambrian

49
Q

Name a morphological synapomorphy of most stramenopiles

A

Stramenopiles have rows of tubular hairs present on the longer of the two flagella they possess.

26.2 Major Lineages of Eukaryotes Diversified in the Precambrian

50
Q

Not all stramenopiles had ancestors with flagella

True/False

A

False

All stramenopiles had ancestors with flagella.

26.2 Major Lineages of Eukaryotes Diversified in the Precambrian

51
Q

Which of the three groups of stramenopiles (diatoms, brown algae, and oomycetes) is photosynthetic?

A

The diatoms and brown algae groups are photosynthetic. The oomycetes are not.

26.2 Major Lineages of Eukaryotes Diversified in the Precambrian

52
Q

All diatoms are unicellular

True/False

A

True!

26.2 Major Lineages of Eukaryotes Diversified in the Precambrian

53
Q

Where are flagella found in the diatoms?

A

Only in its male gametes

26.2 Major Lineages of Eukaryotes Diversified in the Precambrian

54
Q

All of the diatoms synthesize carbohydrates and oils as photosynthetic storage products

True/False

A

True

26.2 Major Lineages of Eukaryotes Diversified in the Precambrian

55
Q

What substance do diatoms give to their cell walls?

A

silica also known as hydrated silicon dioxide

26.2 Major Lineages of Eukaryotes Diversified in the Precambrian

56
Q

Why is the cell wall of a diatom a bit like a petri dish?

A

The cell walls of diatoms are made up of two parts, a top and bottom part, that overlap each other just like the top and bottom part of a petri dish.

26.2 Major Lineages of Eukaryotes Diversified in the Precambrian

57
Q

What makes each diatom morphologically different?

A

The patterns of their cell walls. This is what makes one species of diatoms different from other species.

26.2 Major Lineages of Eukaryotes Diversified in the Precambrian

58
Q

Diatoms can reproduce sexually and asexually

True/False

A

True

26.2 Major Lineages of Eukaryotes Diversified in the Precambrian

59
Q

How do brown algae get their brown colour?

A

They possess a mixture of an orange-yellow pigment called fucoxanthin (phew-co-zan-frin) and chlorophyll a and c which is green.

26.2 Major Lineages of Eukaryotes Diversified in the Precambrian

60
Q

Are all brown algae multicellular or uniceullar?

A

multicellular

26.2 Major Lineages of Eukaryotes Diversified in the Precambrian

61
Q

What is the holdfast of brown algae made from?

A

Its made from alginic acid.

Life: The Science of Biology 11th Edition (60 decks)

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