Chapter 5 - Microbio of Pond Water

Parabasal Bodys

Associated with the Golgi body. Lack mitochondria, instead contain hydrogenosomes that carry out aerobic respiration.

Besides chlorophyll, what additional light-harvesting pigments are found in the cyanobacteria?

In addition to chlorophyll, cyanobacteria have phycobiliproteins which are complexes of pigments and proteins. They also harvest light.

What is a kinetoplast? What photogenic organisms contain this structure?

A kinetoplast is a large mass of DNA in the mitochondrion of a kinetoplastid such as the trypanosomes, which cause African sleeping sickness and Chagas disease.

Saxitoxin

A neurotoxin that produces dizziness, numbness of lips, and difficulty breathing

In which domains are algae, protozoa, and cyanobacteria?

Algae and protozoa are classified in the domain Eukarya. Cyanobacteria are classified in the domain Prokarya

Euglenoids

Can grow heterotrophically or photographically because they contain chloroplasts.

Ciliates

Characterized by having two kinds of nuclei, *micronuclei* and *macronuceli* Micronuclei genes function in sexual reproduction. Macronuceli genes encode for cellular functions

Alveolates

Comprised of the ciliates, dinoflagellates, and apicomplexans. Alveoli associated with the cytoplasmic membrane that may function in maintaining the osmotic balance of the cell

Cyanobacteria

Critical to the evolution of life on Earth because they were first to carry out oxygenic photosynthesis in which oxygen was released into the atmosphere. Over time the oxygen that was released paved the way for development of aerobic bacteria. They may have invaded a primitive cell and established an *endosymbiotic* relationship.

Phagocytosis

Food is taken up when cytoplasmic membrane surrounds food and brings it into the cell for digestion

What is the genus of the causative agent of malaria? In what group does it belong to?

Malaria is caused by the genus Plasmodium, a Protista found in the group Apicomplexa.

What function do the micronuclei play in the ciliates?

Micronuclei contain DNA that encodes for genes concerned with sexual reproduction.

What are mitosomes? In what organisms do they occur?

Mitosomes are reduced mitochondria that lack electron transport components. They occur in the dipomonads of which the human pathogen, Giardia lambdia, is a member

Apicomplexans

Obligate parasites in animals and humans, cause of malaria

Algae

Obtain carbon requirements from oxygenic photosynthesis in which CO2 is fixed into cellular materials and water is split to evolve oxygen.

What makes "red tides", red?

Overgrowths or blooms of microscopic algae cause "Red Tides" and the cellular pigments are responsible for the oceans taking on a red color.

Diatoms

Phototrophic freshwater and marine organisms that are unique in the biological world - synthesize a call wall composed of silica. External portion of the wall is the frustule - very dense

Dinoflagellate

Presence of two different lengths. Produce "red tides" caused xanthophyll in the cells.

Protozoa

Protists, mean "first animals". Genetics has discovered that these organisms have little in common and they're a diverse group. Heterotrophic, unicellular, lack rigid cellulose cell wall characteristic algae or chitinous

Compare and contrast the three mechanisms of motility displayed by protozoa

Protozoa utilize flagella, cilia, or pseudopodia (amoeboid movement) for motility. Flagella and cilia are fibrous, extracellular, protein appendages that wave. Flagella are longer and singular whereas cilia are shorter and more numerous. Pseudopodia are cytoplasmic projections that enable a "crawling" motion.

Mitosomes

Reduced mitochondria that lack electron transport components and Krebs cycle constituents.

In the alveolates, what structure may control osmotic balance?

Sacs called alveoli in the cytoplasmic membrane are thought to control osmotic balance.

Kinetoplastids

Single large mitochondrion in the cell that contains a kinetoplast, which is a large mass of DNA.

What is a frustule, and what unique compound comprises this structure?

The frustule is the cell wall of diatoms. It consists of two halves that fit together like a box with a lid. Frustules are composed of silica.

Name one similarity between algae and plants. Name one difference.

a. Algae and plants are both photosynthetic and have cell walls composed of cellulose. b. Algae, however, can be single-celled and motile

What organisms were formally known as "blue-green algae"? Why are these organisms not algae?

a. Cyanobacteria b. Cyanobacteria are prokaryotic cells that, unlike eukaryotic algae, lack a nucleus and chloroplasts, although they do contain chlorophyll.