Algae Flashcards
What type of lifecycle does algae have?
They can have zygotic, gametic, or sporic lifecycles depending on the species.
What is primary endosymbiosis I?
When a eukaryotic cell engulfed a cyanobacteria which evolved into the chloroplasts. This is known as the archaeplastida which led to green algae, red algae and land plants.
What is primary endosymbiosis II?
Where a eukaryotic cell engulfed a cyanobacteria that evolved into a photosynthetic organelle called the chromatophore.
What is secondary endosymbiosis?
What a eukaryotic cell engulfs another eukaryotic cell that has a primary endosymbiont, creating two sets of membranes are the chloroplasts.
What is red algae (rhodophyta)?
A type of algae that lives mostly in marine, tropical, and warm areas. Most are macroscopic but some are unicellular and filamentous. They have chlorophyll a, phycobilins, and carotenoids.
What is phycobilin?
A type of pigment found in cyanobacteria and red algae.
What is floridean starch?
Stored photosynthetic materials such as cellulose and starch. Similar to glycogen.
How many apical meristematic cells does filamentous red algae have?
1
What type of lifecycle does red algae have?
Alternation of generations
Explain the lifecycle of male red algae up to fertilization
A haploid gametophyte has spermatangia at branch tips. Spermatangia produce spermatia (sperm) via mitosis. Spermatia are not flagellated spermatia are released and drift in water until it fuses with trichogyne.
Explain the lifecycle of female red algae up to fertilization
A haploid gametophyte produces carpogonial branches that have an egg at the base and a long filamentous trichogyne.
Explain the life cycle of algae after fertilization.
Spermatia travels down trichogyne to fertilize egg creating a diploid zygote. Zygote grows in cytocarps which is still a part of the female gametophyte. Zygote grows via mitosis to become carposporophyte making an elongated carposporangia. Diploid carpospores are produced in the carposporangia via mitosis and then are released. Carpospores grow via mitosis into tetrasporophytes which look the same as the gametophytes. tetrasporangia grow in tetrasporophytes. Tetrasporangia undergo meiosis to produce 4 haploid tetraspores. Tetraspores are released and undergo mitosis to form the male and female gametophytes.
Describe a euglenoid
A small unicellular algae that is flagellated. 1/3 of the species have plastids that were acquired via secondary endosymbiosis from green algae. They do not undergo sexual reproduction/meiosis.
What are stramenopiles?
Diatoms, golden algae, yellow green algae, brown algae.
Some species can photosynthesize while others cannot.
They have two different flagella, one is hairy and one is smooth.
All contain chlorophyll a and c
Describe diatoms
Single celled algae that have cell walls composed of silica and fit together like a pill capsule. They are very important for carbon fixation.
What is isogamous reproduction?
There is one female, one male, and they are both the same size and flagellated.
What is anisogamous reproduction?
There is one large female, one small male, and both are flagellated.
What is oogamous reproduction?
A large egg and a small flagellated sperm.
Describe brown algae
Mostly Marie species that have a blade, a stripe, and a holdfast. Some have air bladders called floats. They have a carotenoid pigment called focoxanthin which makes it brown.
What type of lifecycles does brown algae have?
Heteromorphic and isomorphic
Sporic and gametic
What is a heteromorphic lifecycle?
The haploid form (gametophyte) and diploid form (sporophyte) look different
What is an isomorphic lifecycle?
Where the haploid form (gametophyte) and the diploid form (sporophyte) look the same.
What are cryptophyta?
A small group of unicellular algae with two flagella. Their chloroplasts have four membranes due to secondary endosymbiosis
What are haptophyta?
A small group of algae that are unicellular, have two flagella, and a result of secondary endosymbiosis. They have an alternation of generations lifecycle.
