algae Flashcards
What type of organisms are algae?
Chlorophyll-bearing, autotrophic organisms with a thalloid body.
What type of organisms are algae?
Chlorophyll-bearing, autotrophic organisms with a thalloid body.
Are algae aquatic or terrestrial?
Almost all algae are aquatic.
Do algae possess vascular tissue?
No, multicellular algae lack vascular tissue and show little tissue differentiation.
What is the characteristic body type of algae?
Thalloid, meaning it is not differentiated into root, stem, and leaf.
How do algae reproduce?
Vegetatively, asexually by spores, or sexually by the union of gametes.
Are the sex organs of algae unicellular or multicellular?
Generally unicellular, but they can also be multicellular, with all cells fertile.
Do algae sex organs have a protective jacket?
In most cases, the structure lacks a protective jacket.
How does the zygote of algae develop?
It develops by mitosis or meiosis, without forming an embryo.
Do algae exhibit alternation of generations?
Yes, they have distinct alternation of generations.
Are the gametophyte and sporophyte generations of algae independent?
Yes, when present, both generations are independent.
Can algae be prokaryotic or eukaryotic?
They can be either prokaryotic or eukaryotic.
What type of chlorophyll do algae possess?
Algae are chlorophyll-bearing organisms.
Algae primarily possess chlorophyll a, which is the main pigment involved in photosynthesis.
In addition, different groups of algae may have accessory pigments and other types of chlorophyll:
Chlorophyll b: Found in green algae (Chlorophyta).
Chlorophyll c: Present in brown algae (Phaeophyta) and diatoms.
Chlorophyll d: Found in some red algae (Rhodophyta).
Chlorophyll e: Found in some rare golden algae.
These variations in chlorophyll types and accessory pigments help algae adapt to different light conditions in aquatic environments.
Do multicellular algae exhibit tissue differentiation?
Multicellular complex thalli exhibit little tissue differentiation.
What kind of environments are most suitable for algae?
Aquatic environments.
What defines the autotrophic nature of algae?
Their ability to produce food through photosynthesis.
Are algae considered plants?
They are plant-like but differ as their body is thalloid and lacks vascular tissue.
How are the gametes in algae typically united?
Through sexual reproduction by gamete fusion.
What is the primary mode of algae reproduction?
Vegetative, asexual (spores), or sexual reproduction.
Do algae undergo embryonic development?
No, algae do not form embryos during development.
Reproductive Strategies:
the zygote develops directly (by mitosis or meiosis) without forming an embryo is significant, as it differentiates algae from embryophytes (land plants).
Diversity
The diversity in cellular organization (prokaryotic and eukaryotic) is a unique aspect of algae that links them to both simple and complex life forms.
Alternation of Generations:
The independence of both the gametophyte and sporophyte generations is crucial, as it showcases the evolutionary adaptability of algae.
Structure of Multicellular Algae:
multicellular algae can grow into complex structures but lack protective tissues or specialized vascular systems. This makes them distinct from higher plants.
Fertility of Multicellular Sex Organs:
It’s important that all cells in the multicellular sex organs of algae are fertile, which is not typical for higher plants where only specific cells are fertile.
What are prokaryotic algae?
Prokaryotic algae lack internal membrane-bound structures such as the endoplasmic reticulum (ER), Golgi bodies, and mitochondria.
Do prokaryotic algae have a nucleus?
No, they lack an organized nucleus.
What type of ribosomes are found in prokaryotic algae?
Prokaryotic algae have 70S ribosomes.
Do prokaryotic algae have chromatophores?
No, chromatophores are absent in prokaryotic algae.
What surrounds the plasma membrane in eukaryotic algae?
A cell wall surrounds the plasma membrane.
