Microorganisms 2 Algae Flashcards
What are algae?
Algae are simple, plantlike organisms that vary in size, shape, and habitat.
What common feature do all algae have?
All algae have chlorophyll, which allows them to photosynthesize.
How do algae reproduce?
Algae can reproduce sexually and asexually.
Can you name examples of freshwater algae?
Chlamydomonas and Volvox are examples of freshwater algae.
What type of algae are most commonly found in freshwater bodies?
Most green algae live in freshwater bodies.
What are some environments where green algae can grow?
Some green algae are marine, while others grow on moist soil, tree trunks, or walls.
What are the different forms of green algae?
Some green algae, like Chlamydomonas, are unicellular; others, like Spirogyra, form filaments; and some, like Volvox, live in clusters or form colonies.
How does Oedogonium interact with aquatic plants?
Oedogonium fixes itself to aquatic plants.
What is unique about diatoms?
Diatoms are mostly unicellular and have an infinite range of forms.
What are the cell walls of diatoms made of?
Their cell walls are made of silica.
What happens to diatom silica when they die?
When they die, the silica accumulates at the bottom of lakes, rivers, and seas to form siliceous earth.
What are large masses of diatoms floating in the sea called?
Large masses of diatoms floating in the sea are called plankton.
What colors can algae be besides green?
Not all algae are green; some are brown, while others are red.
What causes the brown and red algae to mask the green color of chlorophyll?
Brown and red algae have additional pigments which mask the green color of chlorophyll.
What is an example of a large brown alga?
Giant kelp can grow to a length of 30-60 m.
What is the Sargasso Sea named after?
The Sargasso Sea owes its name to the brown alga Sargassum.
Where do red algae primarily grow?
Red algae are mostly marine, growing in tropical and subtropical seas.
What is the green scum found over wet soil and stagnant pools of water?
The green scum is formed by blue-green algae.
What are blue-green algae more similar to?
These organisms are more like bacteria than like algae, so they are now called cyanobacteria.
What type of algae are seaweeds mostly composed of?
Seaweeds are mostly brown algae.
What is algin and where is it obtained from?
Algin is a gummy substance obtained from kelp. It is used to thicken ice creams, cosmetics, and shaving cream.
What are the uses of algin?
Algin is used in the preparation of medicines and synthetic fibres.
What substances are obtained from kelp?
Iodine and potassium are other substances obtained from kelp.
What is agar and what is it made from?
Agar is a jellylike substance made from certain red algae.
What is agar used for?
Agar is used to culture microorganisms and tissue in the laboratory.
What are diatom shells used for?
Diatom shells are used to make glass, porcelain, ceramics, toothpaste, polishes, and filters.
How are certain red algae consumed in China and Japan?
Certain red algae are dried and sold as papery sheets, eaten as vegetables, or used to make soups.
What is the nutritional significance of algae?
Algae are rich in proteins and minerals and feed a host of aquatic organisms.
What role do algae play in oxygen production?
Algae are the greatest providers of oxygen, accounting for 80% of the oxygen in air.
What is eutrophication?
The enrichment of water bodies by plant nutrients.
What often causes eutrophication?
Sewage and fertilisers draining into water bodies.
What is an algal bloom?
An unnaturally rapid growth of algae that forms a thick layer over the surface of the water body.
What effect do algal blooms have on light and oxygen?
They deprive other organisms of light and oxygen.
What happens to algae when they die?
Bacteria acting on them use up more oxygen.
What is the consequence of eutrophication on aquatic life?
Most other organisms living in the water body die.
