Untitled Prezi

Reproduction

- individual cells of Ulva are not flagellated, but during sexual reproduction the gametes are

- organism has a multicellular sporophyte and gametophyte phase

- individuals look very similar, you can only identify them by the reproductive cells they produce

- Sporophytes (diploid) produce spores(haploid) via meiosis and

- gametophytes (haploid) produce gametes (haploid) via mitosis

Filamentous algae are single algae cells that form long visible chains, threads, or filaments. These filaments intertwine forming a mat that resembles wet wool.

Filamentous algae starts growing along the bottom in shallow water or attached to structures in the water (like rocks or other aquatic plants).

I) As algae reside in water, they do not need the stem structures that a majority of land-based plants do. They simply float along the currents or stick to whatever carries them around.

II) Algae have no risk of drying out and as such have no need for thick cell walls or any waterproof structures

III) Taking advantage of their much thinner cellular structures, algae simply exchange carbon dioxide, oxygen and nutrients with the water all around them.

Algae have much simpler yet more effective ways of reproduction. The reproductive cells can simply swim around, using features like flagella.

One major obstacle all plantlife underwater face is the lack of light for photosynthesis.

Light is a necessary resource in creating the sustenance plants need, and it is chlorophyll that traps the energy of sunlight. However, water-especially seawater tends to absorb most of this energy as it passes through, with red and violet wavelengths being especially susceptible. This is why seawater, especially as you go deeper, tends to be bluer and dimmer.

There are several variants of chlorophyll, with each one being better at collecting a certain wavelength than the others. Chlorophyll A-which is present in all algae- excels in collecting red and violet wavelengths.

Algae have evolved to adapt to the light levels in its surroundings. Multiple compounds have been formed, with each one absorbing light differently. These light absorbing compounds are called accessory pigments.

As an example for how useful this adaptation can be: some algae have a compound that utilizes blue light much better than red and violet light. Accessory pigments are also why algae come in a variety of colours.

During sexual reproduction, algae form differentiated sex cells that fuse to produce a diploid zygote with two sets of chromosomes. The zygote develops into a sexual spore, which germinates when conditions are favorable to reproduce and reform the haploid organism having a single set of chromosomes. This pattern of reproduction is called alternation of generations.

Sexual Reproduction Of Chlamydomonas

Division as described in asexual reproduction takes place only in unfavorable conditions. It produces up to sixteen new individuals which do not develop cell walls. On release from the parental cell they swim around and may meet another individual so they can fuse in pairs to form a zygote.

Volvox

-Asexual

- Makes two Daughter colonies inside the mother cell

- When mature, daughter colonies released as independent ones

Sexual

- Environmental conditions trigger the sexual reproduction

- Some cells either begin to produce egg or sperm cells

- Egg retained by mother colony where fertilization takes place

- Zygote then undergoes immediate meiosis to form diploid cells that will grow into a new colony

Asexual Reproduction Of Chlamydomonas

In favorable conditions the chlamydomonas individuals will continue to grow and then, at a certain size, reproduce by cell division. When each of the units form after cell division they form a new cell wall and a pair of flagella. Then the parent cell wall bursts open and releases the daughter-cell individuals.

The Life of Algae

By: David, Anton, Shereen, and Erik

Reproduction with Algae

Algae also reproduce quite differently compared to flowering plants. They have spores like the ferns, mosses, lichens and liverworts.

Reproduction in algae occurs in both asexual and sexual forms. Asexual reproduction occurs through the fragmentation of colonial and filamentous algae or by spore formation. Spore formation takes place by mitosis. Binary fission also takes place (as in bacteria)

(and Princess, Kiyano and Denisa)

Asexual reproduction typically takes place when the habitat is stable

Binary fission

Colonial Algae Reproduction

The plus one who doesn't even go to Riverside

Algae reproduces very quickly and needs only sunlight (or another form of energy, like sugar), water, carbon dioxide and a few inorganic nutrients to grow.

Chlorophyll and Accessory Pigments

The Structure of Algae

Cellular

Most algae is multicellular.

The giant kelp is an example of a multicellular algea

Most unicellular algae are near microscopic, which makes them seem like plantlike protists

And can grow up to be longer than 60 cm, like the giant kelp

Valonia ventricosa is a protist. It is a unicellular algae and is one of the largest unicellular organisms that exists

The volvox is a great example of a colonial algae

Unicellular algae occur most frequently in water, especially in plankton.

Phytoplankton is the population of free floating microorganisms composed primarily of unicellular algae. Forming a colony of unicellular algae.

Micrasterias, commonly known as green alga, is a eukaryotic, unicellular organism, and species vary in size reaching up to hundreds of microns (very small)

- Both gametophytes and sporophytes look IDENTICAL

-Both the GAMETPHYTE and SPOROPHYTE are dominant

Internal

An example of a multicellular algae is Ulva (Al-va) otherwise known as "sea-lettuce"

Ulva is a special type of edible green Algae that is widely distributed along the coasts of the world's oceans. This Algae thrives in briny waters, particularly in waters enriched with organic nutrients, but can thrive in waters with moderate levels of nutrients. The type species within the genus Ulva is Ulva lactuca. Lactuca meaning "Lettuce" in Latin.

Fun fact: Additionally, this nutrient rich algae has excellent skin-boosting properties therefore is is often used in popular skin care products.

The oedogonium is an example of a Filamentous algae

Algae have cell walls that are made of cellulose.

The oedogonium is an example of a filamentous algea

Plants are unique among higher organisms in that they meet their energy needs through photosynthesis. The specific location for photosynthesis in plant cells is the chloroplast, which also contains a single, circular chromosome composed of DNA.

Most algae are photoautotrophic and carry on photosynthesis. Some forms, however, are chemoheterotrophic and obtain energy from chemical reactions and nutrients from preformed organic matter

MITOCHONDRIA

What is an algae?

There are three kinds of algae. Today, we're only covering one- Green.

Adaptations of Algae to life under water

Green algae

Kingdom: Plantae

Phylum: Chlorophyta

Very Diverse Group

Example: Seaweed

Includes Three Forms: Unicellular, Colonial, And Multicellular

Live In All Environments: Fresh/Salt Water And Soil

Three groups of Algae - Rhodophyta (red algae), Phaeophyta (brown algae) and Chlorophyta (green algae) have been included in the Kingdom Metaphyta. Additionally, the groups cyanophyta (blue-green algae) has been placed in the Kingdom Monera while the group Bacillariophyta (golden-brown algae) has been placed in Kingdom Protista.

Originally considered to be protists because they are single-celled, eukaryotic organisms

They are like eukaryotes because they can be:

• Unicellular
• Colonial
• Multicellular
• Commonly found in fresh or salt waters

They are likes plants because they have:

• Chloroplasts
• Cell walls
• Photosynthesis

Algae will never develop a root, stem or leaf structure.