Question

Summarize the following topics briefly:

Oceanic Alveolates

Protista classficiation

Stramenophiles and global warming

Traits that distinguish charophytes from land plants

Traits charophytes share with land plants

Advantages of seeds over spores

Answer 1

1. Oceanic Alveolates - The Alveolata is a monophyletic group of single-celled eukaryotes that have adopted extremely diverse modes of nutrition, such as predation, photoautotrophy and intracellular parasitism. Most alveolates fall into one of three main subgroups: ciliates, dinoflagellates, and apicomplexans.

Regardless of large morphological differences between ciliates, apicomplexans and dinoflagellates, alveolates share several morphological features:

• A system of adjoining membranous sacs, called “alveoli”, positioned beneath the plasma membrane (synapomorphy); the alveoli can be empty or filled with cellulosic material.
• Distinct micropores through the cell surface that function in pinocytosis (synapomorphy)
• Similar extrusive organelles
• Closed mitosis
• Tubular mitochondrial cristae

2. Protista classification

They are found in moist and watery environments. Their characteristics are similar to animals like their ability to move and they are heterotrophs. They are different from animals being unicellular while animals are multicellular.

Protozoans are classified on the way they move into four categories:

• Sacordinians - move using pseudopod (Amoba).
• Zooflagellates - move using flagella (trypnosoma).
• Ciliaphorans - move using cilia (Paramecium).
• Sporozoans - forms spores (Plasmodium).

Algae

• Phylum Chlorophyta (Green Algae)
• Phylum Rhodophyta (Red Algae)
• Phylum Phaeophyta (Brown Algae)
• Phylum Chrysophyta (Golden algae)
• Phylum Pyrrophyta (Fire Algae)

Fungus-like Protists

• Slime Molds - Slime molds are saprophytic protists.

3. Stramenophiles and global warming

Stramenopiles are Photosynthetic algae, contains 1 hairy flagellum paired with a smooth one, makes large amount of organic matter in oceans. They include diatoms which is unicellular algae that have a unique glass-like wall made of silicon dioxide embedded in an organic matrix, They are So widespread that photosynthetic activity affects global CO₂ levels, when they die, bodies sink to clean floor and are broken down by bacteria-carbon in bodies remains there rather than being released as CO₂ when decomposers respire.

4. Traits that distinguish charophytes from land plants

Charophytes are extremely adapted to an aquatic environment, and the features that distinguish members of the plant kingdom from charophytes are their adaptations to a terrestrial environment.

5. Traits charophytes share with land plants

Chlorophyll is common in both. Characters such as a cell wall composed primarily of cellulose, storage of carbon in the form of starch, and formation of a cell plate are other similarities.

6. Advantages of seeds over spores

• Seeds have outer covering that provides protection.
• Each seed contains nourishment for the embryo inside the seed whereas spore needs nourishment from outer world.
• Inside each seed there is a fully developed embryo that is ready to begin growing, and it provides better dormancy for the plant whereas single cell of the spore must undergo a cell division and special process before the plant or fungus can begin to grow.
• Seeds usually don’t require water to grow, whereas spores need water to grow.