Biodiversity 2 : red and green algae

Eukaryotes

have a membrane bound nucleus and other organelles and has a cytoskeleton

cytoskeleton

network of protein fibers inside a cell that gives it shape, support, and helps it move.

Diploid somatic cell

body (2 set of chromosome)

Haploid cell  germ line cell

one set chromosomes  

Direct life cycles

where juveniles look similar to adults, just smaller

Indirect life cycles

juveniles DO NOT look like smaller adults

oviparity

lay eggs

viviparity

giving birth to live young instead of laying eggs.

Many eukaryotes are single celled: 

meiosis produce gametes or spored

fusion

new combination of genes together

Eukaryotes genetic recombination

• sexual processes (meiosis)

• sexual reproduction occurs universally

• sex cells (gametes are diverse)

isogametes

look the same

anisogamy

not the same

In plants and som ealgea there are:

2 life phases

• one phase will be more visible/dominant in comparison to the other

Archaeplastida

group of organisms that includes plants, red algae, and green algae — all of which perform photosynthesis and store energy as starch.

phylum - rhodophyta (red algae)

1. photosynthetic (poducer) with numerous pigments (chlorophyll a and d, phycoerythrin, phycoyanin, allophycocyanin)

2. alternation of generations: some with similar life stages (isomorphic) others with heteromorphic

3. no flagella

4. cellulose, pectin, agar and carrageenan in cell wall - calcified

alternation of generations - heteromorphic

sporophyte looks distinct from gametophyte

alternation of generations - isomorphic

sporophyte looks identical gametophyte

phylum - Chlorophyta (green algae)

1. Photosynthetic with pigments (chlorophylls a and b, carotenoids)

2. alternation of generations

3. 2 or 4 apical whiplash type flagella

4. cellulose and pectin in cell wall, sometimes calcified

class clorophyceae

flagellate colonial genera isogamy to oogamy

order chlorococcales

• photosynthesis

• non-flagellate unicells and colonial genera

Ulva

isomorphic alternation of generations

life cycle of spirogyra

conjugation involves paring of filament cells, formation of conjugation canals and cell fusion

Charophyta / class charophyceae

oogamy, egg in a protective layer of cells

→ jacket protects egg in dry conditions