When Algae Learned to Hunt

The video explores how marine algae, initially autotrophs, adapted to the post-asteroid impact environment 66 million years ago. With sunlight blocked, some algae evolved into heterotrophs, becoming predatory and mobile. This adaptation is evidenced by fossil records showing structures like flagella. Despite these changes, many algae retained photosynthetic abilities, becoming mixotrophs. This dual capability challenges the binary classification of organisms as either autotrophs or heterotrophs, highlighting the complexity of natural ecosystems.

What was the primary method of energy production for marine algae before the asteroid impact?

• Parasitism

• Predation

• Chemosynthesis

• Photosynthesis

What major event forced marine algae to adapt their way of obtaining energy?

• A volcanic eruption

• An asteroid impact

• A massive flood

• A solar eclipse

How did some marine algae adapt to the lack of sunlight after the asteroid impact?

• By becoming heterotrophs

• By migrating to deeper waters

• By becoming parasitic

• By developing thicker cell walls

What is the term used to describe organisms that can both photosynthesize and hunt for food?

• Autotrophs

• Mixotrophs

• Omnivores

• Heterotrophs

What feature allowed some algae to become more dominant after the extinction event?

• Thicker cell walls

• Ability to swim and capture food

• Increased size

• Ability to live on land