Ecology- Algae

Question 1

What does species growth depend on?

Answer 1

Resource capture capabilities of nutrients and llight.

Question 2

Where do Cyanobacteria thrive?

Answer 2

Warm, stagnant waters with P and N in abundance

Question 3

Structure of a cyanobacteria

Answer 3

Cell envelope of PG layer, plasma membrane, outer mmebrane and as S-layer

Question 4

What facilitates cyanobacteria movement?

Answer 4

Vacuoles with gas-filled cell inclusions or flagella

Question 5

What habitats are cyanobacteria found in?

Answer 5

Tropics, temperate lakes, rivers and estuaries

Question 6

What seasons do cyanobacteria prfer?

Answer 6

Summer and Autmn, or year round in the tropics

Question 7

Why do cyanobacteria thrive year-round in tropics?

Answer 7

Constant solar radiation

Question 8

Why is buoyancy important in cyanobacteria?

Answer 8

Regulation of vertical distribution to specific sunlight and nutrients.

Question 9

How do gas vesicles allow vacuoles?

Answer 9

Net hydrostatic, turgor and atmospheric pressure minus interior gas pressure.

Question 10

How do algae regulate buoyancy?

Answer 10

Lift generated by gas vesicles and density of the cell.

Question 11

What are the feeding behaviours of algae?

Answer 11

Autotrophic and photosynthesis

Question 12

Importance of algae in ecosystems?

Answer 12

Primary producer, generating biomass by fixation of carbon

Question 13

How does carbon productivtiy of algae vary among envrionments?

Answer 13

Eutrophic lake high P and N are highly productive whilst mesotrophic or oligotrophic have less productivity.

Question 14

Lentic

Answer 14

Lakes and Wetlands

Question 15

Lotic

Answer 15

Streams and rivers

Question 16

What are the two types of freshwater envrionments?

Answer 16

Lentic and Lotic

Question 17

What are the two types of Algae?

Answer 17

Planktonic and Benthic

Question 18

How do planktonic and benthic algae differ?

Answer 18

Free floating and substrate fixed.

Question 19

Rhodophyta

Answer 19

Red algae being eukaryotic, lacking flagella, phycobiliprotein pigments, unstacking thylakoids and chloroplasts lacking an external ER

Question 20

Pyrrophyta

Answer 20

Includes dinoflagellates being red, synthesisng CP a and c with high carotenoids

Question 21

Chrysophyta

Answer 21

Gold-brown algase being mostly unicellular, and maybe containing flagella

Question 22

Phaeophyta

Answer 22

Brown algae with chlorplasts with four surrounding membranes, containing fucoxanthin masking cp A and C

Question 23

Chlorophyta

Answer 23

Green algae containing CP A and B, chloroplasts with no external ER and thylakoid stacks of 2-6

Question 24

Dinoflagellates structure

Answer 24

Biflagellates unicellular algae with CP a and c with accesory peridinin and carotene

Question 25

Why are dinoflagellates large-celled in freshwaters?

Answer 25

High nuclear DNA levels reflecteive of their k-strategists

Question 26

Phototactic

Answer 26

Locomotion movement moving towards or away from light stimulation.

Question 27

When do Dinoflagellates exhibit phototactic?

Answer 27

When surface nutrients are limited thus diurnally migrate to low levels

Question 28

When do Dinoflagellate blooms occur?

Answer 28

Mid-late summer

Question 29

How can dinoflagellates be toxic?

Answer 29

Production of neurotoxins like Paralytic Shellfish Poisoning.

Question 30

Diatoms

Answer 30

Non-flagellates in marine and freshwater envrionemtns

Question 31

What are diatoms characterised by?

Answer 31

Thick silica cell wall

Question 32

Why are silica cell walls in diatoms useful?

Answer 32

They are more-efficient to generate and have light

Question 33

Frustule

Answer 33

Composed of two overlapping thecae, each consisting of a valve composed almost purely of silica.

Question 34

What is the frustule made of?

Answer 34

Epitheca and hypotheca

Question 35

What are the two diatom groups?

Answer 35

Centric, radially symmetric, and Pennate, bilaterally symmetric, bipolar and elongated.

Question 36

What ecological niches do diatoms fit in?

Answer 36

Planktonic, benthic, epiphytic and epizoic

Question 37

Chrysophytes

Answer 37

Golden algae with fucoxanthin and cp a and c pigments

Question 38

What pigments do dinoflaggelates contain?

Answer 38

CP a and c with accesory peridinin and carotene

Question 39

Xanthophytes

Answer 39

Yellow-green algae with silica and pectin in the cell wall with neoxanthin, CP A and B and beta carotene.

Question 40

Why are eyespots important?

Answer 40

Allow phototaxis