Evolution

Question 1

Evolution is…

Answer 1

Process by which populations have changed over time in response to changing environment

Question 2

The parameters for natural selection are…

Answer 2

1. diversity based on inheritable traits
2. exhibit reproductive potential
3. live in environments with limited resources
4. competition for limited resources
5. takes time (generations)

Question 3

Natural selection is…

Answer 3

Mechanism for evolution, nature selects for the most advantageous traits (greater reproductive success in an environment)

Question 4

Descent with modification is…

Answer 4

all organisms are related through a common ancestor - developed modifications for changing environments

Question 5

Sexual Dimorphism

Answer 5

differences in phenotype between males & females of the same species

Question 6

Genetic drift

Answer 6

changes in frequencies due to chance - either bottleneck effect or founder effect

Question 7

Hardy-Weinberg equilibrium

Answer 7

when a pop is not evolving and the gene pool is at equilibrium (opposite of conditions for evolution)

Question 8

Evolution caused by:

Answer 8

mutations, non-random mating, gene flow, genetic drift, natural selection

Question 9

Directional Selection

Answer 9

One of the extreme phenotypes is favored (selection against other extreme)

Question 10

Stabilizing Selection

Answer 10

Intermediate phenotype is favored (selection against extremes)

Question 11

Speciation

Answer 11

When two populations of the same species remain isolated from each other and eventually change enough so that they cannot produce viable fertile offspring (no longer the same species)

Question 12

Biodiversity

Answer 12

function of speciation and extinction

Question 13

Morphological Homologies

Answer 13

Similar in structure and form

Question 14

Vestigial Structure

Answer 14

Inherited from an ancestor, but now less complex & functional

Question 15

Molecular Homologies

Answer 15

Similarities between species on a molecular level

Question 16

The five prezygotic barriers

Answer 16

1. Temporal Isolation (different seasons/times of day)
2. Habitat Isolation (live in different habitats)
3. Behavioral Isolation (no sexual attraction)
4. Mechanical Isolation (anatomical incompatibility)
5. Gametic Isolation ( Gametes of different species fail to fuse)

Question 17

Prezygotic Barriers

Answer 17

Prevent mating/ fusing of gametes (fertilization)

Question 18

Postzygotic Barriers

Answer 18

prevent the development of fertile adults
either
low hybrid viability (failure to survive embryonic development/ cannot survive to maturity)
or
hybrid infertility (offspring fail to produce fertile gametes, therefore sterile)

Question 19

allopatric speciation

Answer 19

physical/ geographic separation

Question 20

sympatric speciation

Answer 20

If there is a reproductive barrier between mutations and the parent population, a new species can be formed within a generation (Typically in plants)

Question 21

Adaptive Radiation

Answer 21

emergence of numerous species from a single ancestral species to fill underutilized niches

Question 22

Divergent Evolution

Answer 22

Different species evolve from a common ancestor and diverge as a result of environmental pressures

Question 23

Convergent Evolution

Answer 23

Similarities between species come from similar environmental pressures

Question 24

Punctuated Equilibrium

Answer 24

Very short rapid periods of change followed by long periods of stability

Question 25

Gradualism

Answer 25

Evolution where changes are gradual and small

Question 26

Analogous Structures

Answer 26

Same function but is anatomically different (not the result of a common ancestor) - CONVERGENT EVOLUTION

Question 27

Protocells

Answer 27

phospholipids spontaneously formed cell-like bubbles in the early oceans (early membranes) early membranes trapped other polymers creating an internal aqueous environment inside that was different from that of the surrounding H20 environment

Question 28

Hypothesis for the Origin of Life on Earth

Answer 28

1. The abiotic synthesis of small organic molecules from inorganic precursors 2. Joining of small organic molecules (monomers) into polymers 3. Spontaneous packaging of polymers into simple membranes = PROTOCELLS 4. origin of self-replicating molecules that eventually made inheritance possible (genetic material) 5. The evolution of true cells

Question 29

RNA world hypothesis

Answer 29

first genetic material was RNA and it was self-replicating (RNA was the sole genetic material of earliest cells) possible through RIBOSOMES - folded chain of RNA that can act as catalysts, ribosomes catalyzed RNA replication (self -replication) and then protein synthesis

Question 30

Monomers of proteins (polymer)

Answer 30

Amino Acids

Question 31

Monomers of nucleic acids

Answer 31

nucleotide (4)

Question 32

Monomers of Lipids

Answer 32

Fatty acids (glycerol)

Question 33

Monomers of carbohydrates

Answer 33

monosaccharides

Question 34

Taxonomy

Answer 34

Grouping organisms together based on shared characteristics (pre-darwin)

Question 35

Phylogenetic trees

Answer 35

branching diagram that depicts the lines of evolutionary descent of different organism or species

Question 36

Origins of life on earth

Answer 36

inorganic matter - monomers - polymers - protocells - cells - organisms