Marine Bio chapter 6

Which kingdom do some biologists place algae in, instead of Protista?

Kingdom Plantae - Algae are photosynthetic like plants, but they lack true roots, stems, and leaves, so many biologists still group them with the Protista

Unlike chemosynthetic bacteria, what do all types of algae do?

Perform photosythesis - they use sunlight to make food. Chemosynthetic bacteria get energy from chemical reactions instead.

How are macroalgae best differentiated from phytoplankton?

Mostly multicellular - phytoplankton are single-celled. Both are photosynthetic and eukaryotic, but size and cellularity separate them

How are macroalgae/seaweeds best differentiated from true plants?

No true roots, leaves, or stems - their body is a simple thallus, whereas true plants have differentiated tissues and organs

What is the root-like anchoring structure of many seaweeds called?

Holdfast- anchors the seaweed to rocks or the seafloor but does not absorb nutrients like a true root does.

What does the thallus of a seaweed refer to?

the complete body of the seaweed, it is a simple, undifferentiated body typical of algae

What is the stem-like structure of a kelp called?

Stipe - it supports the blades and connects them to the holdfast, but unlike a true stem it does not conduct water and nutrients through vascular tissue

Which group of algae is found mostly in fresh water and on land, with only a few marine species?

Green algae. While most green algae live in fresh water or on land a few species do occur in the sea

Which group includes the most complex and largest of all seaweeds?

Brown algae. This group includes the giant kelps, which can form underwater forests and are the largest and most complex seaweeds.

In which ocean is the Sargasso Sea located?

The Atlantic ocean. It is a region of the North Atlantic known for floating mats of Sargassum brown algae.

Why are coralline red algae names ‘coraline’?

they accumulate calcium carbonate in their cell walls, making them hard and coral-like. they can be important in building reef structures

Which group of seaweeds has the largest number of species?

Red algae - they are the most species rich group of seaweeds, with thousands of marine species

Where are encrusting algae commonly found living?

On rocks. Encrusting algae grow as hard, thin coatings over rocky surfaces, often in the intertidal zone

What is algin, extracted from seaweeds, used for?

Algin (alginic acid) is used as an emulsifier and thickener in processed foods, such as ice cream and salad dressings

What gelatinous substance extracted from algae is used as a growth medium in microbiology labs?

Agar - used as a gelatinous substance from red algae used to culture bacteria and other microorganisms in petri dishes

What does reproduction in seaweeds generally include?

Both sexual and asexual reproduction. Many seaweeds have complex life cycles that alternate between sexual and asexual phases (alternation of generations)

Which of these is not a marine vascular flowering plant: mangroves, kelps, seagrasses, cord grass, or surf grass?

Kelps. Kelps are brown algae (seaweeds), not vascular flowering plants. Mangroves, seagrasses, cord grass, and surf grass are true flowering plants.

How are marine flower plants best differentiated from seaweeds?

Marine flowering plants reproduce by producing seeds, while seaweeds reproduce via spores or gametes. Flowering plants also have true roots, stems, and leaving.

What are salt-tolerant plants such as salt-marsh plants called?

Halophytes - these plants are specially adapted to survive in salty environments like salt marshes

What kind of coastal waters do mangroves live in?

coastal waters that are well protected from strong wave action, such as sheltered bays, estuaries, and lagoons, where sediments can accumulate