About 90 results for ‘Algae’
-
Algae
Algae are a very large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many distinct organs found in land plants. The largest and most complex marine forms are called seaweeds. Though the prokaryotic cyanobacteria (commonly referred to as blue-green algae) were traditionally included as "algae" in older textbooks, many modern sources regard this as outdated as they are now considered to be bacteria. The term algae is now restricted to eukaryotic organisms. All true algae therefore have a nucleus enclosed within a membrane and plastids bound in one or more membranes. Algae constitute a paraphyletic and polyphyletic group, as they do not include all the descendants of the last universal ancestor nor do they all descend from a common algal ancestor, although their plastids seem to have a single origin. Diatoms are also examples of algae. Algae are found in the fossil record dating back to approximately 3 billion years in the Precambrian. They exhibit a wide range of reproductive strategies, from simple, asexual cell division to complex forms of sexual reproduction. Algae lack the various structures that characterize land plants, such as phyllids (leaves) and rhizoids in nonvascular plants, or leaves, roots, and other organs that are found in tracheophytes (vascular plants). Many are photoautotrophic, although some groups contain members that are mixotrophic, deriving energy both from photosynthesis and uptake of organic carbon either by osmotrophy, myzotrophy, or phagotrophy. Some unicellular species rely entirely on external energy sources and have limited or no photosynthetic apparatus. Nearly all algae have photosynthetic machinery ultimately derived from the Cyanobacteria, and so produce oxygen as a by-product of photosynthesis, unlike other photosynthetic bacteria such as purple and green sulfur bacteria. Fossilized filamentous algae from the Vindhya basin have been dated back to 1.6 to 1.7 billion years ago.
-
-
- Designation:
- bague
-
- Portrayed subject:
- Algae
- Fish
- Fleur-de-lis
-
- Date:
- 19th century
-
PLAGE DE LONGCHAMP A SAINT LUNAIRE
-
- Field(s):
- Drawing
-
- Portrayed subject:
- Algae
- Beach
- Cape (geography)
- Cart
- Landscape
- Littoral zone
-
- Date:
- 19th century
-
-
Ile de Bréhat [titre attribué]
-
- Field(s):
- Drawing
-
- Portrayed subject:
- Algae
- Heath
- Horse
- Landscape
- Littoral zone
- Port (disambiguation)
-
- Date:
- 20th century
-
-
Tas de Goémons [titre attribué]
-
- Field(s):
- Drawing
-
- Portrayed subject:
- Algae
- Landscape
- Lighthouse
- Trail
-
- Date:
- 20th century
-
-
-
Les rivages de l'île Vierge [titre attribué]
-
- Field(s):
- Drawing
-
- Portrayed subject:
- Algae
- Atlantic Ocean
- Landscape
- Lighthouse
- Littoral zone
-
- Date:
- 20th century
-
-
L'île Vierge : parmi les goémons (esquisse) [titre attribué]
-
- Field(s):
- Drawing
-
- Portrayed subject:
- Algae
- Horse
- Landscape
- Lighthouse
-
- Date:
- 20th century
-
-
L'île Vierge : phares et tas de goémons [titre attribué]
-
- Field(s):
- Drawing
-
- Portrayed subject:
- Algae
- Atlantic Ocean
- Landscape
- Lighthouse
- Littoral zone
-
- Date:
- 20th century
-
-
L'île Vierge : tas de goémons fumants [titre attribué]
-
- Field(s):
- Drawing
-
- Portrayed subject:
- Algae
- Landscape
- Lighthouse
- Littoral zone
- Water vapor
-
- Date:
- 20th century
-
-
-
Le débarquement du goémon [titre attribué]
-
- Field(s):
- Drawing
-
- Portrayed subject:
- Algae
- Atlantic Ocean
- Landscape
- Lighthouse
-
- Date:
- 20th century
-
-
De la barque aux brancards (étude) [titre attribué]
-
- Field(s):
- Drawing
-
- Portrayed subject:
- Algae
-
- Date:
- 20th century
-
-
Les barques à marée basse [titre attribué]
-
- Field(s):
- Drawing
-
- Portrayed subject:
- Algae
- Dairy cattle
- Landscape
- Littoral zone
- Sailing ship
-
- Date:
- 20th century
-
-
Barques chargées de goémons (esquisse) [titre attribué]
-
- Field(s):
- Drawing
-
- Portrayed subject:
- Algae
- Atlantic Ocean
- Landscape
- Lighthouse
- Sailing ship
-
- Date:
- 20th century
-
-
-
Goémonier : le transbordement (étude) [titre attribué]
-
- Field(s):
- Drawing
-
- Portrayed subject:
- Algae
- Atlantic Ocean
- Cart
- Horse
- Sailing ship
-
- Date:
- 20th century
-
-
-
Le goémon est déchargé [titre attribué]
-
- Field(s):
- Drawing
-
- Portrayed subject:
- Algae
- Boat
- Cart
- Horse
- Lighthouse
- Littoral zone
-
- Date:
- 20th century
-
-
-
Charrette de goémonier attelée [titre attribué]
-
- Field(s):
- Drawing
-
- Portrayed subject:
- Algae
- Cart
- Horse
- Landscape
- Lighthouse
- Littoral zone
-
- Date:
- 20th century
-
-
Etude de charrette attelée [titre attribué]
-
- Field(s):
- Drawing
-
- Portrayed subject:
- Algae
- Cart
- Horse
- Lighthouse
- Littoral zone
-
- Date:
- 20th century
-
-
Brignogan : goémonier sur le rivage [titre attribué]
-
- Field(s):
- Drawing
-
- Portrayed subject:
- Algae
- Brignogan-Plage
- Cart
- Horse
- Landscape
- Littoral zone
-
- Date:
- 20th century
-
-
Ile Vierge : au milieu des goémons [titre attribué]
-
- Field(s):
- Drawing
-
- Portrayed subject:
- Algae
- Foal
- Horse
- Landscape
- Lighthouse
- Littoral zone
-
- Date:
- 20th century
-
-
-
Le retour des attelages chargés [titre attribué]
-
- Field(s):
- Drawing
-
- Portrayed subject:
- Algae
- Cart
- Horse
- Landscape
- Littoral zone
-
- Date:
- 20th century
-
-
On étend le goémon (projet) [titre attribué]
-
- Field(s):
- Drawing
-
- Portrayed subject:
- Algae
- Fire
- Landscape
- Lighthouse
- Littoral zone
-
- Date:
- 20th century
-