final exam

Question 1

When did the Earth form?

Answer 1

4600 million years ago (Ma)

Question 2

When did the Phanerozoic Eon begin?

Answer 2

541 Ma

Question 3

When did the Paleozoic Era end?

Answer 3

252 Ma

Question 4

When did the Mesozoic Era end (and dinosaurs go extinct)?

Answer 4

66 Ma

Question 5

What are the four main Eons, in order?

Answer 5

Hadean, Archean, Proterozoic, Phanerozoic

Question 6

Which Eon is when life with hard parts first appeared?

Answer 6

Phanerozoic

Question 7

What Eon was Earth a molten mess?

Answer 7

Hadean

Question 8

During which Eon did the first simple life appear?

Answer 8

Archean

Question 9

During which Eon did oxygen start building up?

Answer 9

Proterozoic

Question 10

What are the 3 Eras of the Phanerozoic, in order?

Answer 10

Paleozoic, Mesozoic, Cenozoic

Question 11

What Era was the “Age of Fishes” and land plants?

Answer 11

Paleozoic

Question 12

What Era is known as the “Age of Dinosaurs”?

Answer 12

Mesozoic

Question 13

What Era is known as the “Age of Mammals”?

Answer 13

Cenozoic

Question 14

What are the 12 Periods of the Phanerozoic in order?

Answer 14

Cambrian, Ordovician, Silurian, Devonian, Carboniferous, Permian, Triassic, Jurassic, Cretaceous, Paleogene, Neogene, Quaternary

Question 15

Mnemonic to remember the 12 periods?

Answer 15

“Come Over Some Day, Can People Try Juicing Cold Pineapple Now Quickly?”

Question 16

Which Period did the Cambrian Explosion happen in?

Answer 16

Cambrian

Question 17

Which Period ended with the biggest mass extinction?

Answer 17

Permian

Question 18

Which Period did the dinosaurs go extinct?

Answer 18

Cretaceous

Question 19

Paleozoic:

Answer 19

Cambrian, ordovician, silurian, Devonian, Carboniferous, permian

Question 20

mesozoic:

Answer 20

Triassic, jurassic, cretaceous

Question 21

Cenozoic:

Answer 21

paleogene, neogene, quaternary

Question 22

Element:

Answer 22

A substance made of one type of atom, defined by the number of protons in its nucleus.

Question 23

Radioactive Decay:

Answer 23

The process by which unstable atomic nuclei lose energy by emitting radiation, leading to a change in the number of protons or neutrons, transforming the element into another.

Question 24

Radioisotope Half-Life:

Answer 24

The time it takes for half of a sample of a radioactive isotope to decay.

Question 25

Parent-Daughter Isotope Ratio:

Answer 25

Used in radiometric dating to calculate the age of rocks. The ratio of parent isotopes (unstable) to daughter isotopes (stable) reveals the amount of time that has passed since the rock formed.

Question 26

Uranium-Lead (U/Pb) Decay:

Answer 26

Used to date zircon crystals in igneous rocks and volcanic ash beds. The half-life of 238U is 4.5 billion years.

Question 27

Clair Patterson:

Answer 27

A scientist who used uranium-lead decay to determine the age of Earth, which is about 4.6 billion years. Patterson also worked to reduce lead contamination in the environment.

Question 28

Oldest Zircon Crystals:

Answer 28

The oldest known zircon crystals date back to 4.4 billion years ago.

Question 29

Radiocarbon Materials:

Answer 29

Only organic materials like wood, bone, and shell can be used for radiocarbon dating.

Question 30

Radiocarbon Dating:

Answer 30

Uses 14C and is effective for dating organic materials up to about 50,000 years ago. It differs from other radioisotopes in that it has a short half-life and is mainly used for dating younger fossils and rocks.

Question 31

Early Earth Atmosphere (Archean):

Answer 31

Composed mainly of carbon dioxide, water vapor, methane, and ammonia.

Question 32

Miller-Urey Experiments:

Answer 32

These experiments simulated early Earth conditions and showed that organic compounds (like amino acids) could be formed from inorganic precursors.

Question 33

Murchison Meteorite:

Answer 33

A meteorite that contains amino acids, suggesting that the "stuff of life" might have come from space.

Question 34

RNA as Original Genetic Code:

Answer 34

Scientists believe RNA was the original genetic code because ribozymes (RNA molecules) can self-replicate, which is a key function in life.

Question 35

Molecular Phylogeny:

Answer 35

Helps us understand where life may have originated, such as in deep-sea hydrothermal vents.

Question 36

Stromatolites:

Answer 36

Layered rock structures formed by cyanobacteria, some of the oldest fossils on Earth (around 3.5 billion years old). They perform oxygenic photosynthesis.

Question 37

Great Oxygenation Event (GOE):

Answer 37

The period around 2.4 billion years ago when oxygen levels in Earth's atmosphere significantly increased due to photosynthesis by cyanobacteria.

Question 38

Ediacara Fauna:

Answer 38

The first known multicellular animals (metazoans) from around 600 million years ago.

Question 39

Great Unconformity:

Answer 39

A gap in the rock record, thought to relate to changes in seawater chemistry and helped trigger the Cambrian Explosion.

Question 40

Cambrian Explosion:

Answer 40

The rapid diversification of marine life during the Cambrian Period around 541 million years ago, marked by the appearance of animals with hard shells.

Question 41

Evolution of Land Plants:Ordovician

Answer 41

First primitive land plants, like mosses.

Question 42

Evolution of Land Plants:Silurian

Answer 42

Simple vascular plants.

Question 43

Evolution of Land Plants:Devonian

Answer 43

First forests made of lycopods (seedless vascular plants) and the appearance of primitive gymnosperms.

Question 44

Age of Coal (Carboniferous):

Answer 44

Land plants, particularly lycopods, dominated. This period saw the burial of large amounts of organic carbon, which lowered atmospheric CO2 levels and contributed to a cooler climate.

Question 45

Devonian Period - Age of Fishes:

Answer 45

First jawed fishes appear, along with lobe-finned fishes, which eventually gave rise to tetrapods.

Question 46

Tetrapod Evolution:

Answer 46

Early amphibians evolved from lobe-finned fishes (like Ichthyostega) in the Devonian.

Question 47

Great Dying (Permo-Triassic Extinction):

Answer 47

Occurred around 252 million years ago, marking the end of the Paleozoic Era. The largest mass extinction in Earth's history, caused by volcanic activity (Siberian Traps) and CO2 release, leading to global warming, ocean acidification, and deoxygenation.

Question 48

Amniotic Egg:

Answer 48

An important evolutionary step for reptiles, allowing them to reproduce on land without water.

Question 49

Dinosaurs:

Answer 49

First appeared during the Triassic Period and evolved into the dominant terrestrial vertebrates. The key characteristic of dinosaurs is the mesotarsal joint in the ankle.

Question 50

Pterosaurs

Answer 50

Flying reptiles that coexisted with dinosaurs, also possessing the mesotarsal joint.

Question 51

Archaeopteryx:

Answer 51

A transitional fossil showing both dinosaurian and avian features, linking birds to dinosaurs.

Question 52

Chicxulub Impact:

Answer 52

Evidence suggests an asteroid impact caused the end-Cretaceous mass extinction around 66 million years ago, leading to the extinction of the dinosaurs. Key evidence includes the Iridium Anomaly and the Chicxulub crater in Mexico.

Question 53

Sahelanthropus:

Answer 53

One of the earliest known hominins, about 6-7 million years ago, showing evidence of upright bipedalism.

Question 54

Australopithecines:

Answer 54

Early bipeds with small brains, like Lucy (Australopithecus afarensis) from around 3.6 million years ago.

Question 55

Homo habilis:

Answer 55

The first species of the genus Homo, emerging around 2.5 million years ago.

Question 56

Brain Size Cutoff:

Answer 56

600 cubic centimeters separates Australopithecus from the genus Homo.