Chlorophyceae

Question 1

What are the shared traits that unite the Chlorophyceae family

Answer 1

• cruciate flagellar arrangement
• phycoplast formation of cross wall where spindles turn into microfibers and pull the lateral walls to form a cross wall

Question 2

What type of flagellar apparati do the Chlorophyceae show

Answer 2

• clockwise cruciate, or direct opposite cruciate

Question 3

What type of cell division do Chlorophyceae show

Answer 3

phycoplast - no vesicles forming, spindles turn into microfibers and pull the lateral walls to form a cross wall

Question 4

Describe the volvocales

Answer 4

• Chlorophyceae order
• biflagellated colonies held together by protoplasmic strands and mucilage
• have clockwise cruciate flagellar arrangement

Question 5

Describe the life history of chlamydomonas - vulvocales

Answer 5

• chlorophyceae
• sexual reporduction invovles + and - clonal strains ocmbining to form a 4 flagella zygote which then becomes non motile
• also does asexual reproduction ffrom haploid vegetative cells

Question 6

What do the chlamydomonas produce

Answer 6

astaxanthin as natural sunscreen

Question 7

Describe the Dunaliella - vulvocales

Answer 7

• capable of osmoregulation and photoprotective pigmentation
• glycerol production balances high external osmotic pressure in saline environments

Question 8

Describe the Tetracysteans - vulvocales

Answer 8

• non flagellated
• display desmoschisis whih is when daughter cells are closely connected because of shared cell wall

Question 9

Describe the volvocalean colonies

Answer 9

• the colonies consist of chlamydomonas like bi flagellates
• each genus has a fixed number of cells in colony called coenobial

Question 10

what does coenobial mean

Answer 10

refers to how each genus colony in the vulvocalean has a fixed number of cells

Question 11

Describe the life cycle of volvocales

Answer 11

• have both asexual and sexual reproduction and involves inversion of the colony (the parent colony has to invert itself to release the daughter colonies that are inside)
• asexual reproduction involves clonal production of gonidia into daughter autocolonies
• sexual reproduction differentiation of gonidia into female and small male colonies

Question 12

Describe the inversion by volvocalean colonies

Answer 12

• generation of daughter colonies within a parent colony often starts with gonidium cell
• the gonidium divides to produce daughter cells whose apices are oriented inward
• the developing daughter colony has to then invert itself before it is released by the mother colony

Question 13

What is the direct opposite (DO) group of the chlorophyceae

Answer 13

the Sphaeropleales

Question 14

What is the clockwise cruciate group of the chlorophyceae

Answer 14

Volvocales

Question 15

Describe the sphaeropleales

Answer 15

• chlorophyceae that have DO
• mainly non flagellated coenobial colonies of consistent shape and number of cells
• can form a sarcinoidal colony where the non flagellated daughter cells do not become detached

Question 16

What are the sarcinoidal genera of sphaeropleales

Answer 16

-chlorophyceae with DO
–> Desmodesmus and Scenedesmus (both have coenobial colonies consisting of cells that share cell walls making them sarcinoids)
–> these have no flagella and have spines

Question 17

Describe the pediastrum

Answer 17

• these have asexual reproduction invovling production of motile zoospores
• the zoospores aggregate to form an autocolony that is then released from the parent colony
• this is a coenobial genus

Question 18

Describe the trebouxiophyceans

Answer 18

• these are outsiders of the Chlorophyceae
• can be both in freshwater and terrestrial
• have importance in fossil oil reserves, production of biofuels etc.
• show CCW flagellar arrangements which is odd for chlorophyceae
• have phycoplast
• meta centric centrioles

Question 19

which order can you see centric rings in (chlorophyceae)

Answer 19

Oedogoniales

Question 20

Describe the oedogonialean cell division and rings

Answer 20

• after cytokinesis a ring of cell wall material forms and extends
  -# of rings = # of cell divisions

Question 21

What is the reproductive structures of Oedogonialeans

Answer 21

• asexual ringed multi flagellated zoospores
• zoospores attach to periphytic substrates using their flagella (stephanokontic?)
• flagella are lost and a characteristic holdfast cell beings to divide

Question 22

describe the modes of sexual reproduction in Oedogonialean

Answer 22

1. nannandrous (dwarf male filament)
2. Macrandrous (male looks like female, independant male filament)
3. Gynandrospory (self fertilizer)
4. Idioandrospory (outcrossing)

Question 23

Describe nannandrous sexual reproduction in Oedogonialeans

Answer 23

where there is a dwarf male filament

Question 24

Describe macrandrous sexual reproduction in Oedogonialeans

Answer 24

with independent male filament

Question 25

Describe Gynandrospory sexual reproduction in Oedogonialeans

Answer 25

selfing

Question 26

Describe Idioandrospory sexual reproduction in Oedogonialeans

Answer 26

outcrossing

Question 27

Describe the chaetophorales order in the chlorphyceae

Answer 27

• they have phragmoplast with plasmodesmata
• quadriflagellated reproductive cells
• most attach to surfaces and are heterotrichous