Biology Exam 2 Study Guide

Front 1

always a small population getting smaller

consequences- little genetic variation, reproductive problems, syptomatic of inbreeding, low sperm count

Back 1

Continuous Drift

Front 2

population alternately ceases for a time and then starts again

Back 2

Intermittent Drift

Front 3

loss of genetic variation that occurs when a new population is established by a very small number of individuals

Back 3

Founder Effect

Front 4

reduction of a population's gene pool and changes in gene frequency are produced when few members survive

Back 4

Bottleneck Effect

Front 5

one mater per mate

Back 5

Monogamy

Front 6

four mates per fmale

Back 6

polyandry

Front 7

twenty mates per male

Back 7

polygyny

Front 8

matings between geneticlally related individuals

it increases homozygosity and leads to a high incience of recessive, genetic diseases

Back 8

Inbreeding

Front 9

Mutation introduces variation

Selection removes variation

Back 9

Mutation-Selection Balance

Front 10

Drift fixes neutral alleles

Most variation we see in population is neutral

rate of fixation independent of population size

Back 10

Natural Theory of Evolution

Front 11

2Tu

Back 11

General Distance

Front 12

a process whereby over time one species diverges to become two or more species

one species splits into 2 or more daughter species which thereafter evolves as distinct lineages

Back 12

Speciation

Front 13

prevents genetic exchange and allows divergence

the cause of speciation

no fertile offspring

no gene flow

Back 13

Reproductive Isolation

Front 14

prevents members of different species to reproduce; (no loss of gene flow)

Back 14

Prezygotic Barrier

Front 15

prevents a fertilized egg from developing into a fertile adult

Back 15

Postzygotic Barrier

Front 16

adapted to eating in the littoral zone(by the shore)
-long wide body size
-short snout
-small eyes

Back 16

Benthic 3-spine stickleback

Front 17

adapted to eating in the open water
-tapered and slim body size
-long snout
-large eyes

Back 17

Limnetic 3-spine stickleback

Front 18

new species evolves from a single ancestral species while inhabiting the same geographic region

Back 18

Sympatric Speciation

Front 19

new species evolves from single species while inhabiting different geographic region

Back 19

Allopatric Speciation

Front 20

a graphic representation of lines of descent among organisms or their genes

Back 20

Phylogenetic Tree

Front 21

the evolutionary history of a particular group of organisms or their genes

Back 21

phylogeny

Front 22

a biological group that is given a name

Back 22

Taxa

Front 23

a monophyletic group made up of an ancestor and all of its descendants

Back 23

Clade

Front 24

pertaining to a group that consists of an ancestor and all of its descendants

Back 24

Monophyletic group

Front 25

pertaining to a group that consists of an ancestor and some of its descendants

Back 25

Paraphyletic group

Front 26

pertaining to a group that consists of multiple distantly related organisms and does not include a common ancestor

Back 26

Polyphyletic group

Front 27

two phylogenetic groups that are each others closest relatives

Back 27

Sister species

Front 28

trait originally present in the ancestor of the given group, may be retained or changed in the descendants of that ancestor

Back 28

Ancestral trait

Front 29

a trait that differs from the ancestral trait

Back 29

Derived Trait

Front 30

similarity between two or more features that is due to inheritance from a common ancestor. the structures are said to be homologous, and ach is a homolog of the others

Back 30

Homology

Front 31

the presence in multiple groups of a trait that is not inherited from the common ancestor of those groups

Back 31

Homoplasy

Front 32

Independent evolution of similar features from different ancestral traits

Back 32

Convergent Evolution

Front 33

a). infer phylogenetic tree from aligned sequences and determine best-fitting evolutionary model
b). reconstruct protein sequence at ancestral node by maximum likelihood
c). synthesize oligonucleotides and assemble gene for ancestral protein by stopwise PCR
d). subclone assmbled gene into vector, transform cultured cells, and express ancestral protein
e) purify ancestral protein and characterize function using trans-activation, binding or other assay

Back 33

Ancestral Gene Reconstruction

Front 34

ancestors to all life on earth

-lack nucleus
-no membrane bound organelles
-one ring of DNA (one chromosome)
-plasmids
-ribosomes

Back 34

Prokaryotes

Front 35

plasmids transfer from one bacterium to another

Back 35

Conjugation

Front 36

DNA transfered from one bacterium to another by a virus

Back 36

Transduction

Front 37

Increases variation in bacterial populations by taking DNA from the environment and recombining it with the bacterial genome

Back 37

Natural Transformation

Front 38

Movement of genes from one species to another

-usually interferes with determination of evolutionary relationship

Back 38

Horizontal Gene Transfer

Front 39

-evolutionarily ancient
-critical role in translation
-evolved slowly

Back 39

rRNA

Front 40

organism whose cells contain complex structures enclosed within membranes
-set apart from prokaryotic cells because of containing a nucleus

Back 40

Eukaryotes

Front 41

-mitochondria(makes ATP for energy) and chloroplasts(permit photosynthesis) formerly small prokaryotes
-engulfed by larger ancestral eukaryote
-already had internal membranes
-mutualism: beneficial relationship for both
-became interdependent

Back 41

Theory of Serial Endosymbiosis

Front 42

describes life cycle of plants , fungi, and protists

Back 42

Alternation of Generations

Front 43

haploid multicellular phase of plants and algae that undergo alternation of generations with each cell containing a single set of chromosomes

Back 43

gametophyte

Front 44

diploid multicellular phase of plants and algae that undergo alternation of generations with each cell having a double set of chromosomes

Back 44

sporophyte

Front 45

-haploid
-unicellular
-produced by sporophyte
-non flowering plants
-short lived

Back 45

spores

Front 46

-flowering plant
-supply of stored food (endosperm)
-wrapped in a coat
-long lasting, resistant to harsh conditions
-introduces dormant phase that allows embryo to develop when conditions are favorable

Back 46

seed

Front 47

-evolutionary breakthrough in colonization of land
-conducting tissue (water & nutrients)
-more than one cell type
-found in vascular plants
ex. club mosses, ferns

Back 47

vascular tissue

Front 48

transport tissue in vascular plants(mainly water)
composed of primarily dead cells

Back 48

xylem

Front 49

transport living tissue in vascular plants(mainly nutrients)
composed of primarily living cells

Back 49

phloem

Front 50

opens pores in leave for gas diffusion
-lets carbon dioxide in and oxygen out
-closed if very dry to prevent water loss

Back 50

stomata

Front 51

-longitudinal rod
-structural suppoet
-gelatinous material of disks in vertebral column
-flexible rod with muscles attached
-facilitated movement

Back 51

Notochord

Front 52

runs beneath dorsal surface in vertebrates develops into CNS (brain and spinal cord)

Back 52

Dorsal Hollow Nerve Chord

Front 53

feeding adaption
-allows water that enters mouth to exit without going through system (later modified for gas exchange)
-in terrestrial chordates do not fully form

Back 53

Pharyngeal slits (pouches)

Front 54

contains skeletal elements and muscles propulsive force in many aquatic species

Back 54

Postanal Tail

Front 55

distinguished from non vertebrate chordates by:
-cranium: distinct and well differentiated head region; brain encased within protective cranium of bone or cartilage

-neural crest cells
development of skeletal structures, including cranium, jaws, teeth, and nerves

Back 55

Craniates

Front 56

consistent with large size and more active lifestyle

-vertebral column: notochord is replaced during development by a vertebral column; series of bony or cartilaginous vertebrae enclose and protect nerve chord

Endoskeleton: bone and cartilage-very strong and flexible ; grows wit animal-living cells within skeleton; increases the potential size and power

internal organs: liver, heart
adaptions to respitory and circulatory systems: more active metabolisms

adaptions for feeding, digestion and nutrient absorption

Endoskeleton

Back 56

Vertebrates

Front 57

vertebrate animals with 4 limbs
ex. amphibians, reptiles, birds, mammals,snakes

evolution: new niches for animals to radiate out into ; strong selection for animals who could tap into niches

adaptions: protection from dissection; ability to extract oxygen from air; ability to support weight out of water; evolution of rib cage to protect internal organs

Back 57

Tetrapod