Ch 25 Bio 11B

Some of the oxygen formed as a result of photosynthesis may have combined with which of the following metals in the ocean?

iron

The first _____ on Earth may have arisen in hydrothermal deep-sea vents, at the shore, or elsewhere in a smelly chemical ocean.

life, lifeforms, cells, organisms, living things, or life forms

3.2 billion year old microfossils found in deposits which were once microbial mats in shallow South African marine environments provide compelling evidence for the structure of the first

living cells

Cold periods that led to glaciation and a drop in sea level during the last 2 million years created an opportunity for humans and other animals to

migrate between once disconnected continents

_____ are the energy-producing organelles in eukaryotic cells. Correct Answer Blank 1: Mitochondria Need help? Review these concept resources.

mitochondria

A major advantage of ________ is that it enables cells to specialize into tissues and organs having specific functions.

multicellularity

Early organisms were thought to be autotrophs with the ability to synthesize complex _______ compounds from simple compounds ________ and later use them as an energy source. Listen to the complete question

organic inorganic

Dome-shaped structures made of mats of cyanobacteria and trapped mineral deposits called ________can be found throughout the world; some are as old as 2.7 billion years.

stromatolites

Rodinia was a single_______ that existed during the Proterozoic eon.

supercontinent, landmass, or continent

Climate and atmosphere are some factors

that affect the ability of organisms to survive and reproduce

Fossilized stromatolites are sedimentary deposits

that provide indirect evidence that life began over 2.7 billion years ago

Multicellularity has arisen independently in different eukaryotic supergroups.

true

In the following list, place the different types of organisms in order according to their appearance in the fossil record starting with those that appeared earlier in the fossil record at the top.

1. First animals 2. first land plants 3. insects 4.mammals 5.First hominds

Order different types of organisms according to their appearance in the fossil record starting with the oldest (i.e. those that appeared earlier in the fossil record) at the top.

1. invertebrates 2. first land animals 3. amphibians 4. reptiles 5. flowering plants

Organisms belonging to domain Eukarya appear in the fossil record about how long ago?

1.5 BYA

Place the following changes in the configuration of Earth's continents in order according to their appearance in Earth's history with the oldest configuration at the top. Instructions

1.Rodinia formed 2.Pagnea formed 3. Australia and Antarctica separated 4. A land bridge between Asia and North America formed

How many years between the origins of photosynthesis and substantial amounts of oxygen in the Earth's atmosphere?

200 million

Early Earth experienced temperatures over which of the following?

2000oC

What was the approximate temperature range of the early Earth?

2000oC to -50oC

What percent of the weight of the Tagish Lake meteorite is organic matter?

3%

Currently the oldest microfossils that are supported by isotopic data and by spectroscopic analysis are how many billion years old?

3.5

It is most likely that Earth's first organisms emerged and lived at very high temperatures about how many years ago?

3.8 BYA

Since its formation, Earth has undergone much change. In fact, no rocks have been found from the first

500-700 million years of Earth's history

The current Cenozoic era began about about how many years ago?

65 MYA

Compared to today's atmosphere, Hadean Earth was which of the following?

A dynamic environment, shifting between a fiery and sometimes frozen Earth, that was unlikely to have supported life

Which of the following is true of the beginning of the Paleozoic era?

A great diversification of life occurred and many separate continents existed.

The three modern monophyletic clades called domains evolved from which of the following?

A single primitive cell of the Archean eon

At the end of the Paleozoic era the Earth formed with of the following?

A single supercontinent

Which of the following are characteristics of eukaryotes?

Ability to be unicellular or multicellular Mitochondria Physical separation of transcription and translation

The gradual movement of continents due to plate tectonics did which of the following?

Affected the climate and made it possible for populations to mix and interbreed

Dramatic shifts in which of the following have led to mass extinctions and influenced the course of evolution?

Atmospheric composition Climate

Biologists believe that the first living things on Earth had the ability to synthesize complex organic compounds from simple inorganic compounds and later use them as an energy source. Therefore those organisms were which of the following?

Autotrophs

Identify the Earth's first organisms.

Bacteria and archaea

Why do we say that bacterial colonial aggregates are not truly multicellular?

Because they lack differentiation and integration of function.

In multicellular organisms cells should be connected to each other in order to do which of the following?

Communicate with each other

True multicellularity (characterized by specialized, coordinated, communicating cells) is only found in the domain___

Eukarya or Eukaryota

The domain that includes organisms that possess mitochondria, an endomembrane system that compartmentalizes certain organelles, and can be truly multicellular is called

Eukarya or eukaryotes

True or false: Fossil records indicate that both prokaryotes and eukaryotes evolved around the same time.

False The eukaryotes appear in the fossil record much later than bacteria and archaea. They appear only about 1.5 BYA, whereas the earliest microfossils (possible prokaryote) are at least 3.5 billion years old.

Which of the following describes when single-celled organisms were the only form of living organisms?

For most of the history of life on Earth

Which of the following is true of the beginning of the Paleozoic era?

Glaciation and a drop in sea level

Which if the most abundant amino acid found in the Tagish Lake meteorite?

Glycine

Which of the following statements is correct regarding the Hadean Earth?

Hadean Earth could not have supported life because of the hot mass of molten rock during this period

The first 500-700 million years of Earth's history comprised an eon called which of the following?

Hadean eon

The early atmosphere of planet Earth probably had which of the following?

High levels of CO2

If it were possible to conduct sophisticated microscopic and chemical analysis of the oldest known microfossils, one should be surprised to observe evidence of which of the following? I. double-stranded DNA II. a nuclear envelope III. a nucleoid IV. a nucleolus V. nucleic acids

II and IV

Under which of the following scenarios is early life on Earth least likely to have arisen?

In an ice-covered ocean during a Snowball Earth event

Which of the following statements is true of multicellularity?

In multicellular organisms, cells are connected and communicate with each other.

As carbon dioxide levels in the atmosphere decreased what happened to the temperature on Earth?

It cooled.

Which of the following statements about the Cambrian explosion is not true?

It includes a Snowball Earth and is characterized by mass extinctions.

Which of the following is an advantage of sexual reproduction?

It increases genetic diversity.

Evidence indicates that carbon fixation is which of the following?

It is an ancient process.

Compared to DNA, RNA can be described as which of the following?

Less stable than DNA

Sexual reproduction allows greater genetic diversity through which of the following the processes?

Meiosis and crossing over

The formation of Earth's ozone layer enabled which of the following to occur?

Migration of living organisms from a watery to a terrestrial environment

Which of the following statements is true?

Most enzymes are proteins.

Which of the following statements about the origin of multicellularity are true?

Multicellularity has arisen independently in different eukaryotic groups.

Early life may have arisen during the Archean, but evidence of life in the form of microfossils is difficult to interpret for which reason?

Nonbiological processes can produce microfossil-like structures

Many microfossils are 1-2 μm in diameter and appear to be single-celled, with no external appendages or internal structure. This suggests that the organisms that were fossilized to form these microfossils resembled which of the following?

Present-day prokaryotes

Multiple lines of evidence indicates that the first cells were most likely which of the following?

Prokaryotic

According to the hypothesis of an RNA world, the first nucleic acid that permitted self-replication was which of the following?

RNA

The idea that RNA may have been the first nucleic acid to permit self-replication and the fact that ribosomes translate RNA into proteins support the _____ ______ hypothesis.

RNA world

Which of the following eras started with the expansive diversification of life of the Cambrian period?

The Paleozoic era

How has the temperature of Earth changed since the planet's formation?

The planet has been cooling

Evidence indicates that the first cells were probably prokaryotic.

True

True or false: Cells underwent the most evolutionary change when life was primarily aquatic.

True lthough much diversification of eukaryotes occurred in both terrestrial and aquatic habitats, most of the major innovations of cells occurred early in the history of life, when living organisms primarily inhabited aquatic environments.

It is likely that Earth's first organisms emerged and lived when the Earth was at which of the following temperatures?

Very high temperatures

Prokaryotic organisms that are closely related to eukaryotes and are often found to inhabit extreme environments such as those with very high temperatures, high pressure, or high salt are

archaea

Life is thought to have arisen during the _______eon.

archean

Changes in the concentration of gases such as O2, N2, CO2, and CH4 in the have had important effects on the evolution of life on Earth.

atmosphere

The first organisms and only living cells on Earth for more than a billion years were_____ and _______

bacteria archaea

One way of looking for evidence of ancient life is to look for organic molecules that are clearly of biological origin; such molecules are called which of the following?

biomarkers

Organic molecules which are clearly of biological origin are called

biomarkers

Weathering occurred more rapidly under hot, wet conditions than under_____ , conditions.

cold, dry

Mitochondria and chloroplasts are both believed to have entered early eukaryotic cells by a process called ______

endosymbiosis

Archaea are most closely related to

eukaryotes

The action of the shifting continental plates of Earth has important effects on the course of_______- of living organisms by reproductively isolating populations or allowing previously separated populations to interbreed.

evolution

True or false: Eukarya are believed to have diverged from the bacterial line of descent. The Eukarya are therefore more closely related to the Bacteria than to the Archaea.

false

True or false: Evidence indicates that carbon fixation is a relatively new process that cells have acquired.

false

What effect does weathering of rock have on the amount of Carbon dioxide in the atmosphere?

CO2 levels decrease.

What effect did volcanic eruptions have on the amount of carbon dioxide in the atmosphere and oceans?

CO2 was added to the atmosphere and ocean.

Changes in concentration of which of the following atmospheric gases have affected the evolution of life on Earth?

CO2, O2, N2, and CH4

Which of the following compounds in the ocean precipitates and sequesters carbon dioxide?

CaCO3

Cyanobacteria, algae, and modern land plants use which of the following pathways for carbon fixation?

Calvin cycle

Rapid diversification of life occurred during which of the following periods?

Cambrian

Which of the following support the RNA world hypothesis?

Ribosomes translate RNA into proteins in the cell. The RNA molecule may have been the first nucleic acid to permit self-replication. Research has shown that it is possible to synthesize RNA without pure ribose. High concentrations of RNA may have occurred in ice crystals in salty water, promoting bond formation.

Microfossil-like structures as evidence of life can be difficult to find and to interpret for which reason?

Rocks older than 3 billion years change significantly over time.

A single supercontinent existed in the Southern Hemisphere during the Proterozoic eon; it began to break up into smaller continents approximated 700 MYA. What was this supercontinent called?

Rodinia

According to some scientists, the first nucleic acid which permitted self-replication was RNA. This is supported by the well known fact that in addition to storing genetic information, RNA can do which of the following?

Serve as an enzyme to catalyze reactions

For most of the history of life on Earth, the only form of living organisms were which of the following?

Single-celled

Which of the following occurred during the Cenozoic era of the Phanerozoic eon?

The separation of Australia and Antarctica The continued growth of the Atlantic Ocean The separation of Greenland and North America A rise in sea level

One of the major benefits of multicellularity is that it allows organisms to deal with their environments in novel ways through which of the following?

The specialization of cells into various types of tissues and organs

Define microfossils.

They are fossilized forms of microscopic life.

Life started as a single cell in the Archean eon and then evolved into which of the following?

Three domains

During the early and late Proterozoic, life was decimated because of which of the following?

Three sudden exceptionally sharp drops in temperature