Biology II- Chapter 25

Macroevolution

broad pattern of evolution above the species level

chemical and physical processes on early Earth may have produced very simple cells through a sequence of stages

1. Abiotic synthesis of small organic molecules

2. joining of these small molecules into macromolecules

3. packing of molecules into protocells(precells)

4. organ of self-replicating molecules (Pre RNA/DNA)

earth formed how many years ago?

4.6 billion

when were seas formed?

4 million years ago

in the 1920s, A.I. Oparin and J.B.S Haldane independently hypothesized what?

that the early atmosphere was a reducing environment

in 1953 Stanley Miller and Harold Urey conducting lab experiments that demonstrated what?

that the abiotic synthesis of organic molecules in a reducing atmosphere was possible

the first organic compounds may have formed in reducing conditions where

the opening of volcanoes

reanalysis of molecules formed in Millers experiments found that

numerous amino acids formed under conditions simulating volcanic eruptions

where have organic compounds been produced?

in deep seas hydrothermal vents, areas on the seafloor where hot water and minerals gush from the earths interior into the ocean

"Black smokers" release water at what temp?

300-400C

Alkaline vents release water at what temp and what pH?

pH: 9-11

temp: 40-90C

where are organic compounds more suitable to form?

near alkaline vents

what could provide energy for their own synthesis?

pH gradient

what could be another source of organic molecules?

meteorites

RNA monomers have been produced _ from simple molecules

spontaneously

small organic molecules polymerize when they are concentrated on what?

hot sand, clay or rock

what are key properties of life and may have appeared in protocells

replication and metabolism

how may have protocells formed?

from fluid filled vesicles with a membrane like structure

in water, ___ and other organic molecules can spontaneously form vesicles with a lipid bilayer

lipids

what was the first genetic material?

RNA

RNA plays a central role in what?

protein synthesis

RNA molecule called __ have been found to catalyze many different reactions

ribosomes

What has produced self replicating RNA molecules

natural selection

copying errors would have occasionally resulted in ___ __ more adept for self replication

RNA molecules

RNA molecules that were more __ or __ more quickly would have left most descendant RNA molecules

stable or replicated

RNA could have provided the template for

DNA, a more stable genetic material

what kind of DNA is more chemically stable and can be replicated more accurately than RNA

double stranded DNA

What kind of rock are deposited into layers called Strata and are the richest source of fossils

sedimentary

few organisms have been __

fossilized

the fossil record is biased in favor of species that

1.

2.

3.

1. existed for a long time

2. were abundant and widespread

3. had hard parts, such as shells or skeletons

how can we infer relative aged of fossils?

by the order of fossils in rock strata

the age of the fossil can be determined by using

radiometric dating

a radioactive "" isotope decays to a "" at a characteristic rate

parent, daughter

each isotope has a know "__"

half life

what is a "half life"

the time taken for half of the parent isotope to decay

the age of some fossils can be estimated by measuring what?

the ratio of the radioactive isotope carbon-14 to the stable isotope carbon-12

radiocarbon dating can be used to date fossils up to how long?

75,000years

The geologic record is divided into

H.A.P.P: Hadean, Archaen, Proterozioc, and Phanerozoic eras

the Phanerozoic Is divided into three eras:

Paleozoic, Mesozoic, Cenozoic

the first single celled organism is?

prokaryotes

the oldest known fossils are

stromatolites, rocks formed by the accumulation of sedimentary layers on bacterial mats

red in rock shows what?

oxygen present

stromatolites date back to?

3.5 billion years ago

How is O2 produced?

oxygenic photosynthesis reacted with dissolved iron and precipitated out to produce banded iron formation

the oldest fossils of eukaryotic cells date back to?

1.8 billion years ago

Eukaryotic cells have a

1.

2.

3.

4.

1. nuclear envelope

2. mitochondrion

3. endoplasmic reticulum

4. cytoplasm

Eukaryotes originated by __ when a prokaryotic cell engulfed a small cell that would evolve into a mitochondrion

endosymbiosis

DNA is inside what of eukaryotic cells?

nuclear membrane

symbiotic relationship helps with what?

providing support

mitochondria and plastics likely descended from __?

bacterial cells

Key evidence supporting an endosymbiotic origin of mitochondria and plastids:

1.

2.

3.

1. inner membranes of both organelles are similar to plasma membranes of living bacteria

2. DNA structure and cell division are similar to bacteria

3. both organelles transcribe and translate their own DNA

the oldest fossils of multicellular eukaryotes are what?

small red algae from 1.2 billion years ago

What were an assemblage of larger and more diverse soft-bodied organisms that lived from 635-541 million years ago

the Endicaran biota

what explosion refers to a sudden appearance of fossils resembling modern animal phyla in the __ period.

Cambrian Explosion

The Cambrian Explosion provides the first evidence of what?

predator- prey

Fungi, plants, and animals began to colonize land about

500 million years ago

many plants evolved adaptations to what?

defy gravity, reproduce on land and to avoid dehydration

and __ likely colonized land together

plants and fungi

__ and __ are the most widespread and diverse land animals

arthropods and tetrapods

what are the 4 layers to the Earth?

crust, mantle, outer core, inner core

Movements in the mantle cause the plates to move over time in a process called

continental drift

the Landmasses of Earth have formed a super continent three times over the past billion years

Rodinina

Pannoita

Pangaea

the formation of Pangaea had many effects such like:

a deepening of ocean basins

a reduction in shallow-water habitat

a colder and drier climate inland

Continental drift has many effects on living organisms

• organism must adapt, move, or risk extinction as the climate changed in response to continents moving toward or away from the equator

• separation of landmasses can lead to allopatric speciation

the big five mass extinctions

1.

2.

3.

4.

5.

1. Permian Extinction

2.

3.

4.

5.