Chapters 15-17 Flashcards Preview

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Flashcards in Chapters 15-17 Deck (98)
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1

when did earth form

about 4.6 billion years ago

2

how first life may have evolved

1. abiotic synthesis of small organic molecules, such as amino acids and nitrogenous bases
2. joining of these small molecules into polymers, such as proteins and nucleic acids
3. packaging of these molecules into “protocells”
4. origin of self-replicating molecules that eventually made inheritance possible

3

what does O2 tend to do?

As a strong oxidizing agent, O2 tends to disrupt chemical bonds.

4

next 3 stages of life

1. Abiotic synthesis of polymers
2. Formation of protocells
3. Self-replicating RNA

5

macroevolution

evolutionary change above the species level. encompasses...
-the origin of a new group of organisms through a series of speciation events and
-the impact of mass extinctions on the diversity of life and its subsequent recovery.

6

radiometric dating

-is based on the decay of radioactive isotopes (unstable forms of an element)
-can date rocks and fossils.
-carbon-14 decays to another element

7

plate tectonics

the theory that Earth’s crust is divided into giant, irregularly shaped plates that essentially float on the underlying mantle.

8

permian extinction

linked to the effects of extreme volcanic activity.

9

cretaceous extinction

included most dinosaurs. may have been caused by the impact of an asteroid.

10

adaptive radiations

periods of evolutionary change in which many new species evolve from a common ancestor.

11

"evo-devo"

combines evolutionary and developmental biology.

12

taxonomy

branch of biology concerned with identifying, naming, and classifying species.

13

binomial

two-part scientific name

14

phylogeny

The evolutionary history of a species or group of species

15

systematics

a discipline of biology that focuses on
-classifying organisms
-determining their evolutionary relationships.

16

phylogenetic tree

a hypothesis of evolutionary relationships.

17

analogy

Similarity due to convergent evolution

18

cladistics

groups organisms by common ancestry.

19

clade

monophyletic group that consists of an ancestral species and all its evolutionary descendants—a distinct branch in the tree of life.

20

Cladistics two main types of characters

1. A shared ancestral character
2. A shared derived character

21

shared ancestral character

common to members of a particular clade, but originated in an ancestor that is not a member of the clade.

22

shared derived character

common to members of a particular clade and is not found in its ancestors.

23

parsimony

the adoption of the simplest explanation for observed phenomena.

24

molecular systematics

uses DNA or other molecules to infer relatedness.

25

molecular clock

a method that estimates the time required for a given amount of evolutionary change.

26

Earliest form of life

prokaryotes about 3.5 to 2 billion years ago

27

origin of single-celled eukaryotes

1.8 billion years ago. originated when prokaryotic cells became capable of aerobic respiration or photosynthesis

28

origin multicellular eukaryotes

1.2 billion years ago. larger organisms 600 million years ago.

29

earth's eon history

hadean, archaean, Proterozoic, and Phanerozoic

30

paedomorphosis

the retention in the adult body of structures that were juvenile features in an ancestral species