Lecture Notes on the Origin and Evolution of Life

These flashcards summarize key concepts regarding the origin and evolution of life, prokaryotes, viruses, and related scientific theories.

Why was the Miller experiment important?

It tested the hypothesis of how organic molecules can form in conditions similar to early Earth.

When did life arise on Earth?

About 4 billion years ago.

What environment did the Miller experiment simulate?

An early Earth environment where simple molecules can combine into organic compounds.

What are biological macromolecules believed to have formed from?

Small molecules combining in a chemical 'soup'.

Which cellular structures evolved from membrane infolding?

Organelles such as the nucleus.

What is endosymbiosis?

A theory proposing mitochondria and chloroplasts originated as free-living bacteria that were engulfed by other microbes.

What significant life form was dominant in the Paleozoic era?

Invertebrate animals flourished during the Cambrian period.

What is multicellularity, and why is it important?

Multicellularity allowed for specialized cells and an explosion in the variety of body sizes and forms.

What did photosynthesis change in early Earth's atmosphere?

It altered the air composition, leading to an increase in atmospheric oxygen.

What organism likely lived first on Earth?

Prokaryotic cells, which appeared around 3.5 billion years ago.

What are the main divisions of primates?

Prosimians, hominoids, and monkeys.

What misconception might arise regarding the evolution of humans and chimpanzees?

Humans did not evolve from chimps; they share a common ancestor.

What is a prion?

An infectious protein that can cause diseases and trigger normal proteins to adopt abnormal shapes.

What is the primary function of a virus?

To infect host cells and replicate using the host's cellular machinery.

How do vaccines work?

They stimulate an immune response to protect against future infections by a virus.

What are viroids?

Infectious RNA molecules that can replicate within a host cell but do not encode proteins.

How do proteins on viruses contribute to infection?

They bind with specific host cell proteins, enabling the virus to enter the cell.

What significant event marks the end of the Permian period?

The largest mass extinction in Earth's history.

What evidence do scientists use to classify prokaryotes?

DNA sequences, chemical composition, and ribosomal structures.

What is horizontal gene transfer?

Transfer of genetic material between organisms in ways other than traditional reproduction.

What role do nitrogen-fixing prokaryotes play in ecosystems?

They convert atmospheric nitrogen into ammonia, essential for plant life.

Why is antibiotic resistance a concern?

It's caused by the overuse of antibiotics, leading to the proliferation of resistant bacteria.