Ch.3.1 Early Life -3.2 Prokaryotes

• Photosynthetic eukaryotes contain both mitochondria and chloroplasts. Which sequence of events most likely describes the evolution of this group?

• Ancestral prokaryote engulfs and oxygen-using energy-harvesting prokaryote and then engulfs a photosynthetic Prokaryote

• • Ancestral prokaryote engulfs a photosynthetic prokaryote and then engulfs an oxygen-using energy-harvesting prokaryote

• • Ancestral prokaryote engulfs an energy-harvesting prokaryote that does not rely on oxygen and then engulfs a photosynthetic eukaryote

• • Ancestral prokaryote engulfs a photosynthetic prokaryote and then engulfs an energy-harvesting prokaryote that does not rely on oxygen

Which of the following organelles originated from endosymbiosis?

• • Nuclear membrane and Golgi apparatus

• • ER and chloroplasts

• • Chloroplasts and mitochondria

• • Mitochondria and Golgi apparatus

The following are four hypothesized stages of the origin of life. Place them in the correct order.

1. Origin of self-replicating molecules

2. Joining of small organic molecules into long-chain

molecules

3. Abiotic synthesis of small organic molecules

4. Packaging of molecules into fatty membranous

Proto-cells

• 1,2, 3,4

• • 3,2,4,1

• • 4,2, 3,1

• • 3, 1, 2,4

• • 2,1, 4,3

Why do some scientists believe that RNA, rather than DNA, was the first genetic material?

• RNA has both information storage and catalytic properties

• RNA contains uracil in place of thymine

• • RNA could evolve into DNA

• • RNA can replicate more accurately than DNA

• • All the photo-cells on early Earth contained RNA

A species of bird finds its way to the Galápagos Islands, where there are several ecological niches. The species evolves into many new species to fill all the unfilled niches. This is an example of:

• • resource partitioning

• • adaptive radiation

• • endosymbiosis

• • gradualism

Prokaryotes lack some parts found in eukaryotic cells, including which item?

• a nuclear membrane

• DNA

• • on or more chromosomes

• • a plasma membrane

• • all of the above are missing in prokaryotic cells

Which gets its energy from sunlight and its carbon from ingesting other organisms?

• • photoautotroph

• • chemoautotroph

• • photoheterotroph

• • chemoheterotroph

Without prokaryotes:

• • much decomposition in the soil would stop

• • synthesis of vitamin K in the human gut would cease

• • plants would have fewer soil nutrients to absorb

• • all of these would occur without prokaryotes

Organisms that cannot survive the presence of oxygen are called:

• • obligate anaerobes

• • facultative aerobes

• • obligate aerobes

• • none of these, no such organisms exist