Lecture 5: Algae Flashcards

1
Q

Where is photosynthesis widespread?

A

Photosynthesis is widespread (polyphyletic) in Eukaryotes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are algae?

A

Algae are photosynthetic eukaryotes other than land plants

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Describe most algae

A
  1. Most algae are aquatic (both freshwater and marine)

2. Many are unicellular

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Describe most multicellular species

A

Most multicellular species produce bodies in which all cells are in contact with the environment (simple multicellularity)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What two things are closely related? What is the group they form called?

A

Plants and green algae are closely related and together form a monophyletic group.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What features of land plants are present in some green algae?

A

Many of the…
1) key physiological
2) structural features
of land plants are present in some green algae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

The ____________, ______________, and _________ are the green algae most closely related to land plants.

A

1) Charales
2) Coleochaetales
3) Zygnematales

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What do the Charles, coleochaetales, and zygnematales all have?

A

1) All occur in freshwater
2) All have a haplontic life cycle
3) All produce sporopollenin in the cell walls of the zygote

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the six features found in the green algae and in plants that are thought to have played a role in the transition to land?

A

Great POMPS

1) The use of the enzyme Glycolate oxidase in photoresipiration
2) Phragmoplast
3) Oogamy
4) Matrotrophy
5) Plasmodesmata
6) Sporopollenin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is oogamy?

A

Oogamy is a mode of fertilization where a nonflagellated gamete (the egg) is fertilized by a flagellated gamete, as in humans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is matrotrophy?

A

Matrotrophy is the retention of the fertilized egg (the zygote) and supply of “maternal” care to it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is sporopollenin?

A

Sporopollenin is a complex polymer hat serves a protective function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the phragmoplast?

A

The phragmoplast is the cytoskeletal structure responsible for the deposition of the cell plate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are plasmodesmata?

A

Plasmodesmata are microscopic channels that allow communication between cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is glycolate oxidase?

A

Glycolate oxidase increases the efficiency with which 2-Carbon molecules produced during photorespiration are recycled

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is a phylogeny?

A

A phylogeny is a starting point of the evolutionary diversification of plants and a way to organize information about the past

A hypothesis of the evolutionary relationships among species or other entities

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What does a node indicate?

A

A node indicates the last common ancestor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What does monophyletic mean?

A

A group consisting of all the descendants of a common ancestor
- MUST all have the SAME last common ancestor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is a paraphyletic group?

A

A paraphyletic group includes some, but NOT all, descendants

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

When are paraphyletic groups useful?

A

Paraphyletic groups can be useful when they refer to organisms that are functionally similar
- For example, Turtles, Lizards, and Crocodiles are not all descendants but are functionally similar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Within a Eukaryotic tree, which relationships are unresolved?

A

the deepest relationships are unresolved (polygamy)

- It’s therefore harder to know who’s related to who

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is polygamy?

A

a flat line indicating we don’t know the relationship

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are algae?

A

Algae is an informal term for photosynthetic eukaryotes that are not “land plans” and are typically aquatic
- polyphyletic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is polyphyletic?

A

when you group an organism by characteristics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Describe rhodophyta
- Red Algae - Mostly multicellular - Chlorophyll (a & c) and phycobilins (red pigment) - Some crustose red algae grow at a depth of 250 meters
26
What are two traits of algae that are of interest
1) Cellulose in cell walls (occurs in all of these groups) | 2) Sporopollenin (found in cell walls of some chlorophytes and in land plants and close green algal relatives)
27
Describe green algae
- Chlorophyll a and b - starch stored in chloroplasts - 2-7 thylakoids stacked in grana - stellate flagella
28
State 3 types of green algae
1) Chlorophyta 2) Volvox 3) Dasycladales 4) Ulva (sea lettuce)
29
What is chlamydomonas?
a unicellular chlorophyte with a haplontic life cycle (vegetative - doing photosynthesis and metabolic activity)
30
Describe gametes
gametes can't live very long - if they don't fuse then they die - spores can survive much longer
31
What is ulva?
Sea lettuce | - a multicellular chlorophyte with alternation of generations
32
All plants have ______________ and are distinguished by __________
All plants have alternation of generations and are distinguished by ploidy
33
All _____________ have a haplontic life cycle
All streptophyte algae have a haplontic life cycle
34
Features found in all streptophyte algae
- fresh water - haplontic - sporopollenin (zygote) - phragmoplast - plasmodesmata - open mitosis - glycolate oxidase
35
What feature did all 3 candidates of the closest alga relative to plants share?
the presence of sporopollenin in the wall of the zygote
36
What is sporopollenin?
Sporopollenin is the most degradation resistant polymer known - protection from UV radiation, desiccation, damage
37
Where do green algae grow?
green algae grow in freshwater habitats where water levels fluctuate
38
Filaments type of cell division
filaments, single plane of cell division
39
Sheets type of cell division
Sheets, two planes of cell division
40
Parenchymatous type of cell division
Parenchymatous, three planes of cell division
41
_________ and ________ allow for complex multicellular development
phragmoplast and cell plate allow for complex multicellular development
42
What are plasmodesmata?
span two cell walls and their connections together - control what moves between them
43
All cells have _____________-
intercellular connections
44
What moves between cells?
There are intercellular movements of proteins, mRNA, small molecules, and virus particles
45
What happens in "open" mitosis?
In "open" mitosis, the nuclear envelope breaks down before the chromosomes separate (and then reforms around the two sets of chromosomes) - fungi and animals
46
What happens in "closed" mitosis?
In "closed" mitosis, the nuclear envelope remains intact (later pinches to form two nuclei)
47
What is rubisco?
rubisco is the enzyme that catalyzes the entry of CO2 into the Calvin cycle
48
What can rubisco also catalyze?
Rubisco can also catalyze a reaction with O2 (instead of CO2) which leads to a loss of carbon and energy - this is because rubisco has trouble distinguishing O2 and CO2 - higher rates at higher temperatures
49
What is glycolate oxidase?
an enzyme that helps mitigate against the losses in carbon and energy that occur when rubisco reacts with oxygen - deals with temperature fluctuations - selectivity comes with speed --> if very selective also very slow
50
What are oogamous and what does it mean?
Choleochaete and Chara/Nitella are oogamous meaning they make eggs and swimming sperm
51
What are conjugating algae and what does it mean?
Zygnematales are conjugating algae - fertilization involves cytoplasmic bridges between cells - eggs don't move and sperm/male component moves
52
Where are gametes produced?
gametes produced in gametangia
53
Where are sperm produced?
sperm produced in the antheridium
54
Where are eggs retained?
eggs retained in the oogonium
55
All green algae have _________ via ________
all green algae have haplontic life cycles via mitosis
56
What are chara lifecycles triggered by?
chara lifecycle triggered by stress | *form a diploid*
57
What is matrotrophy?
wall ingrowths indicate nutrient transfer to zygote
58
What do zygotes undergo and what does this produce?
zygotes undergo meiosis which produce four haploid daughter cells that undergo 2 to 3 mitotic divisions which produce haploid "meiospores" that then disperse
59
How can haploid alga also reproduce?
can also reproduce asexually (mitotically produced zoospores)
60
What are zygnematales?
1) no swimming sperm | 2) dismiss floating around and have to come into contact with a spirogyra
61
What is desiccation tolerance?
the ability to survive drying and go back to metabolic processes when rehydrated
62
What is photorespiration?
when rubisco acts on oxygen with an acceptor carbohydrate molecule
63
Gamete vs. spore
Gamete: always fuse - no independent existence Spore - grow up on its own - persists
64
What is alternation of generations?
genetically distinct in policy