Test Exam 1.6 (Dinophyta [Dinoflagellates])
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What is the cellular characteristic of dinophyta?
ALL ARE UNICELLULAR
What is the stored food? How does this compare with plants?
store food as starch (same has higher plants); also fats and oils
- in plants: starch is always in a plastid (chlorophlast)
- in dinoflagellates: starch found in and some found out chloroplasts
Explain the cell wall
- It's to the inside of the membrane
- some have none, but have a differentiated membrane called a periplast (unarmored; noctiluca is one species like this)
Most have a cell wall composed of cellulose plates located in vesicles to the inside of the plasma membrane (not outside like other cell walls)--> Armored
Where are the flagella located? HOw many?
two flagella located in perpendicular grooves; they have a groove that flagella lies in as it circles the organism. A second groove is smaller, with the other lying in it (the other flagella is longer than the groove causing it to stick out)
- rolling around
- tensile like
uninucleate (unusual features [prokaryotic-like= mesokaryotic nucleus])
As opposed to a eukaryotic cell, what happens inn a dinoflagellate?
What does it make them?
as opposed to a euk, whose chromosomes condense in prophase, the mesokaryotic dinoflagellates stay condensed throughout.
This makes them prokaryotic like. Their DNA is not associated with histones like eukaryote. (no histones in dinoflag. and few proteins)
Why is there a divide in what dinof are classified as?
- some considered to be protozoa
- people say algae partly because half are autotrophic and the other half are heterotrophic
Other dinoflagellates have both __.
mesokaryotic and eukaryotic
- asexual (divide by mitosis)
- difference: nuclear envelope persists instead of disintegrating. The chromosomes attach to it as channels of cytoplasm inavde the nucleus and have microtubules; no mitotic spindle
- most marine, usually in warm water, but not always
- some freshwater (Lake Erie)
- chl a and c
- like diatoms, several carotenoids (golden brown); alot are reddish
Cell wall __ is different.
What happens to the cell wall during division?
- the cell wall gets split
- -each daughter cell gets half and has to grow the other part
- - some plates, not all
What do dinoflagellates cause?
- not common
- for those wh do the only diploid is the zygote
red tide; can multiply explosively
Dinoflagellates are important as __. They like __, but can __.
Some are __. What value does this have?
Some live __.
the base of the food chain
live in cool water
bioluminescent; to confuse predators; it occurs when they are agitated
in other organisms; gives coral its color and food; no cell wall as it functions as chloroplast
Explosive population growth of dinoflagellates produces __ (not really __; doesn't always have to be __; some are __)
- red tides
nutrients in excess, temp, current, wind patters etc.
Health problems in people can be caused by the production of __ (released when __) and sometimes __ (secreted by __) by some species of __. The most common genera involved are __, __, and __.
- the cells die
- living cells
In most cases, __ are the direct source of the toxins for people. They feed by __ and __. When the __ is toxic dinoflagellates, the __ accumulate the toxins. The toxins have no adverse effect on the shellfish. Other animals, including people which eat the shellfish may be affected by the toxins. The toxins are not _ to all organisms. More __ are toxic than __.
- filtering large amounts of water
- removing any particulate matter
- particulate matter
- equally toxic
Diarrhetic Shellfish Poisoning
- caused by which toxin __.
First comfirmed outbreak: __, 1976; in __ 1990
Dinoflagellates responsible: __
Toxin: a group of toxins, including __, htat cause __.
Symptons: Appear after __ to __ hours after ingestion. Diarrhea, nausea, vomiting, ab pain, headache, malaise, tremor, difficulty swallowing, slow HR, decreased reflexes, pupil dilation, chronic exposure may promote formation of __; no fatalities have been reported
- okadaic acid
- Japan; N. America
- Dinophysis spp
- okadaic acid
- gastrointestinal illness
- 30 min to 12 hours
- digestive tract tumors
True or False:
Small amounts of okadaic acid shellfish will kill you.
Some don't have __
False: excessive amounts; but you'd have to eat alot
and some don't have antidotes
Treatment of Diarrhetic shellfish poisoning
supportive; recovery within three days with or without treatment
Neurotoxic Shellfish Poisoning
First confirmed outbreak: __, 1880. Has been reported also from the __, __, and __.
Dinoflagellate responsible __.
- West cosst of Fl
- east coast of Fl
- NC coast
- Gulf of Mexico
Neurotoxnis, maainly brevetoxins
Symptoms of Neurotoxic Shellfish Poisoning
Onset usually occurs within __ of ingestion; milder than _.
__ affect Na transport in the __ and cause __ in the skeletal muscle. Ab pain, nausea, vomiting, diarrhea, progressive tingling from around the mouth to the pharynx, trunk, and limbs. Also: dizziness, malaise, muscle weakness and pain, tremor, confusion, slow HR, dilated pupil dilation, convulsions (rarely)
__ if inhaled in aerosol form.
- three hours of ingestion
- inhibition of neuromuscular transmission
- resp. asthma-like symptoms
Treatment of neurotoxic shellfish poisoning
no antdote; supportive; duration approx. 2 days
Paralytic Shellfish Poisoning
- much more serious than __ or __.
- Occurrence: form __ to __; the coast of __
Dinoflagellates responsible: __(3)__
- diarrhetic or neurotoxic shellfish poisoning
- Alaska to sourther Californa; New England
Alexandrium spp, Gymnodinium catenatum, Pyrodium bahamense
a group of 12-18 different neurotoxins that are not destroyed by heating; at least one is prob an alkaloid (saxitoxin)
Paralytic shellfish poisoning
- symptoms: mainly affect the __ and __
- Almost immediate: tingling sensation of the face and fingertips, headache, dizziness, nausea, vomiting, diarrhea
Within 24 hours: Muscular paralysis, liver damage, resp. or cardiac failure, possible death through respiratory paralysis
More than __ reported human deaths.
peripheral and CNS
Treatment of PSP
no antidote; people surviving the first 24 hours have a good dchance of recovery; patient has stomach pumped and is given artificial respiration; no lasting effects
Ciguatera Fish Poisoning
The US has been reported in Hawaii, the tip f FL, also in PR and the US Virgin Islands
Dinoflagellate responsible: __.
consumption of contaminated reef fish, like barracuda, grouper, red snapper, and morey eel
the heat- stable neurotoxins cugatoxin and maitotoxin
Symptoms of Ciguatera Fish Poisoning
Initial: Diarrhea, vomiting, ab pain
Later: neurological dysfunction, including numbness and tingling around the mouth, hands, and feet; joint and muscle pains with weakness and cramps; dizziness; anxiety; sweating; headache; and reversal of temperature sensation, where cold feels hot and vice versa; heart arrhythmia; paralysis and death have been documented, but symptoms are usually less severe
no antidote; supportive; patient has stomach pumped and decontaminated with charcoal; treatment with mannitol may relieve some symptoms; recovery time variable and may take weeks, months, or years. Survivors do recover
__ is a newly discovered dinoflagellate that has at least __ in its life cycle. Many of the stages are __, while several are __. Several __ have also been found.
Sometimes, it looks like a __; sometimes, it does not.
pfiesteria piscicida (means fish killer)
- 22 identified stages
- cyst stages
Pfiesteria piscida is the only dinof. knwon to produce high amounts of __.
It is the only toxic dinoflagellate knonw to show __ to targeted finfish or shellfish prey, hence the names __ and __. This occurs in response to an unidentified substance in fish __. When threshold concentrations of these substances are detected, the dinoflagellates do what?
- direct, "deliberate" chemosensory response
- killer alga and ambush predator
- secreta/ excreta
- swim up into the water and excrete the eotoxins (sits in the sediments until the fish comes)
Several stages, including both __ and __, are toxic to __ and __. A small __ is the most toxic.
Effects on fish: __
- flagellated and amoeboid forms
- finfish and shellfish
flagellated vegetative form
the toxins induce the formation of open ulcerative sores, hemorrhaging, and death
Effects on humans of Pfiesteria piscida : The toxins can be absorbed from __ or __. Known effects have come from exposure to the aerosols from dilute lab cultures of the organism's toxic stages or direct contact with the culture medium.
Hours to days: narcosis, respiratory distress with asthmas like symptoms, severe stomach cramping, nausea, vomiting, eye irritation with reddening and blurred vision, central nervous sytem dysfunction; sudden rages and personality change
water or fine aerosols
ANS dysfunction: localized sweating, erratic heart beat; reversible cognitive impairment and short-term memory loss
elevated hepatic liver enzyme levels and high P excretion in one human exposure suggesting hepatic and renal dysfunction
Months to years( chronic)
- asthma like symptoms
- exercise fatigue
- sensory symptoms: tingling or numbness in lips, hands, and feet
- easy infection and low counts of several T-cell types, which may indicate immune system suppression
Pfiesteria piscida : Populations increase under conditions of __; have been implicated in __ from Delaware Bay through the Gulf Coast, including hte Chesapeake Bay.
Come about due to increase in nutrients from __.
- phosphorous enrichment
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