How can dinoflagellates be harmful to humans? a. They are transmitted by mosquitoes and cause malaria. b. They produce toxins that can be absorbed by clams and other shellfish which, when eaten by people, can lead to paralytic shellfish poisoning. c. They cause amoebic dysentery which leads to severe diarrhea and dehydration. d. They are transmitted by tsetse flies and cause 'sleeping sickness.'

Video transcript

Hi everyone. Let's look at our next problem. It says blank are known for causing red tide bioluminescence and releasing dangerous toxins in the water. Well, let's recall from our content video that red tide is a phenomenon in the ocean um that causes bioluminescence that you see at night. Um It's does it's um cause a level of dangerous toxins in the ocean water. And it's also known as red tide because during the daytime you see a sort of reddish brownish color. Um and it's the result of a population explosion or bloom of dino fragile. It's and some diatoms and they just occasionally have this huge explosion of the population. And the result is you do see that red brown color in the water. And uh the large numbers produce this toxin that often causes unpleasant sort of rashes causes people to feel sick if they go in the water at that time. And you see this beautiful bioluminescence at night. So when we look at our answer choices, we see that choice B is dino fragile. It's so that would be our correct answer here. Let's look through other answer choices. Choice A cyanobacteria. Um That's not an answer. They don't cause red tide. These are green photosynthetic bacteria. Make up a large amount the primary producers in the ocean due to their large numbers and photosynthesis. Choice C is zero flag. Let's um These are also not responsible for red tide. They're primarily freshwater. Protas owns that. Move about using flag ela thus their name. And then Choice D red algae despite their name with red in it. They are not what causes red tides. Red algae um are algae that have that red color due to using accessory pigments that are reddish in color. Um and one of the largest groups of eukaryotic algae. But despite the name red algae, they are not what causes red tide. And again, what causes that red tide bioluminescence and the release of dangerous toxins Is choice be dino flag. Let's see you in the next video.