Exam 3 Flashcards
1
Q
Mendelian genetics
A
study of variation through patterns and prediction of inheritance
the probability of what things will look like
2
Q
Mendel’s contributions
A
a. genes are material elements (chromosomes)
b. genes come in pairs (homologous chromosomes)
c. elements can retain character through generations (at times expressed or not)
d. gene pairs separate when forming gametes (meiosis)
3
Q
monohybrid characteristics
A
a. 3:1
b. F1 heterozygous (word by itself implies dominant)
4
Q
dihybrid characteristics
A
a. 9:3:3:1
b. two traits = four gametes
c. each allele will have one of each trait
d. label each box of Punnett square for both traits
5
Q
shortcut (or check) to dihybrid Punnett square
A
make monohybrid square for each trait and multiply answers together
6
Q
incomplete dominance
A
when traits of F1 hybrids falls between the phenotypes of the two parents (when red and white flowers produce pink)
with dominance lacking, an intermediary trait manifests
7
Q
codominance
A
neither of the heterozygous alleles is dominant over the other and both affect the phenotype
8
Q
antigen
A
protein on outside of cell (A and/or B)
9
Q
example of an X-linked disease
A
red-green colorblindness
higher percentage are male, because females have two X chromosomes and thus a greater chance at getting a normal allele)
10
Q
example of autosomal recessive disorder
A
albinism
requires two recessive genes to manifest
11
Q
nondisjunction
A
when members of a chromosome pair fail to separate during anaphase I, resulting in some cells with either one or three chromosomes)
12
Q
nondisjunction in meiosis I
A
pairs of homologous chromosomes fail to separate
13
Q
nondisjunction in meiosis II
A
sister chromatids fail to separate
14
Q
aneuploidy
A
abnormal number of chromosomes
15
Q
trisomy 21
A
Down syndrome
three number 21 chromosomes
16
Q
Klinefelter syndrome
A
male with an extra X (XXY)
17
Q
Turner’s syndrome
A
female with only one X (XO)
18
Q
chromosome deletion
A
portions missing from chromosome
19
Q
chromosome inversion
A
portions cut out and reinserted upside down
20
Q
translocation
A
all or part of a chromosome fused to a different chromosome
21
Q
chromosome duplication
A
portion of chromosome duplicated
22
Q
pleiotropy
A
one gene influences several hereditary characters
23
Q
polygenic inheritance
A
variations in characteristics that occur along a continuum, like skin or eye color, or height, which are controlled by several genes
24
Q
pedigrees
A
tool for mapping family relationships
25
biotechnology
the manipulation of organisms or their components to make useful products
26
transgenic organisms
organisms artificially altered with genes from other species
27
where HGH (human growth hormone) reproduces
genetically modified bacteria
28
GMO (genetically modified organisms)
taking genes from another organism and putting them into another organism to take advantage of a particular trait
29
plasmid
a small ring of self-replicating DNA separate from the chromosome(s), found in prokaryotes and yeasts
30
restriction enzymes
the “cutting enzyme,” naturally occurring enzymes in bacteria that can cut DNA fragments at specific sequences
31
DNA ligase
the “pasting enzyme,” one that attaches or rejoins DNA fragments with complementary ends
32
recombinant DNA
DNA combined from two different sources
33
recombinant DNA process
• gather plasmids from bacteria and genes of interest from DNA
• restriction enzymes recognize and bind to specific sequences
o breaks apart sugar-phosphate backbone, opening up the DNA helix
o two plasmids start at opposite ends of strands (5 – 3 direction) in search of recognition sequences
o enzyme cuts out DNA at recognition sequences
o leaves overhangs, or sticky ends
• DNA ligase pastes everything together
• now can reproduce the recombinant DNA
34
polymerase chain reaction (PCR)
multiple copies of DNA from a small sample
35
materials needed for PCR
1. original DNA
2. DNA nucleotides
3. DNA polymerase
4. 2 primers (around gene you want)
36
PCR process
* process is a series of being heated (to separate strands) and cooled (to reform the double helix)
* heat breaks the hydrogen bonds, separating them into two single strands
* as it cools, added primers attach to complementary starting points
* nucleotides added
* 2 polymerases travel down strands in 5 – 3 direction
* result is two identical copies of section wanted
37
steps to artificially producing a white sheep from a black sheep
• retrieve donor egg from black sheep
• remove the haploid nucleus
• retrieve a diploid skin cell from white sheep
• fuse the cell and enucleated egg using electricity
o simulates fertilization
o results in an egg with a diploid nucleus
• implant the embryo in a surrogate
• a clone of the white sheep is born
o contains DNA from both (most from the cell, though some from the mitochondria in the egg)
38
evolution
change in populations of organisms
39
natural selection
a method whereby nature (the environment) selects for the traits that allow organisms to best survive and reproduce in the current environment
40
Darwin's observations at Galapagos Islands
a. rich diversity of life, unique flora and fauna
| b. striking ways in which organisms are suited to their environments
41
Darwin's finches
1. specimens collected looked vastly different but were same species, all finches
2. he notices the birds all have traits allowing them to flourish in their specific habitat
3. these finches have relatives on the mainland, so these must have adapted or diversified
4. concludes that nature selected for the animals with traits most suited for their environment
42
Darwin's influences
Charles Lyell
author of Principles of Geology
geological features we see today could have been formed by processes still occurring today
Darwin realized that the earth is changing
Jean-Baptiste de Lamarck
organisms can acquire traits in their lifetime and give those traits to their offspring (disproven)
living things can change over time
Darwin becomes interest in this possibility of change, in how organisms interact with their environment
Georges Cuvier
studied the fossil record
each layer had unique animals, therefore God must have had many creations after extinctions
Darwin interested in the idea of extinction, and in the fossil record’s calling into question the idea that God created everything just as it is
43
key points of The Origin of Species
“descent with modification”
Darwin argued that each living species descended from a succession of ancestral species, and that small changes could add up over long periods to produce the diversity of species we see in the world today
natural selection is the mechanism
organisms that are more likely to survive and reproduce pass their genetic material on to future generations possess traits useful for surviving in current environment
44
misconceptions about evolution
evolution does not say humans came from monkeys
though we have a common ancestor
evolution is not a goal, with everything on its way to becoming human
humans are not “best”
everything has been evolving for millions of years
45
allele
alternate forms of a gene occurring at a locus, one from each parent on each chromosome
46
species
* group of actually or potentially interbreeding natural populations that are reproductively isolated
* not hybrids made in captivity with human intervention
* willing and able to reproduce naturally
* organisms able to breed naturally and produce offspring that can survive and reproduce
47
reproductive isolation
groups no longer able or willing to reproduce
48
speciation
an evolutionary process in which one species splits into two or more species
the formation of a new species
49
homologies
common characteristics inherited from a recent common ancestor (grasping hands)
50
analogy
common characteristics that evolved independently (fins in ocean dwellers)
51
evolution
change in populations of organisms
52
underlying principle of evolution
all life on Earth has a common ancestor
53
microevolution
change in allele frequencies between generations (short-term)
54
five agents of microevolution
```
mutation
gene flow
genetic drift
nonrandom mating
natural selection
```
55
gene flow
transfer of alleles due to introduction of new breeding population
reduces differences between populations
56
genetic drift
random change in allele frequency visible in small groups due to reduced breeding populations and/or chance
57
founder effect
genetic drift
small number of breeders act as founding population (introduction of new environment vs. extinction)
58
bottleneck effect
genetic drift
drastic reduction in population size after cataclysmic event or circumstances (like mass extinction), producing offspring not genetically representative of original population (ex: cheetahs)
59
natural selection
a method whereby nature (the environment) selects for the traits that allow organisms to best survive and reproduce in the current environment
only method that promotes adaption
60
stabilizing selection
intermediate phenotypes favored (ex: birth weights), reducing variation and promoting adaptation
61
directional selection
one extreme of phenotypes favored over the other (ex: giraffe’s long neck) that shift the overall makeup of a population toward that one direction
62
disruptive selection
both extremes favored (ex: differences in male/female coloration, etc.)
63
nonrandom mating
sexual selection, whereby individuals with certain traits are more likely than others to find mates
64
macroevolution
long-term evolution and speciation
65
how enough change occurs to cause speciation
```
allopatric speciation (geographic isolation)
behavioral isolation
temporal isolation
ecological isolation
sympatric speciation
```
66
allopatric speciation
species develop because of a geographic barrier or physical barrier (desert, ocean, highway, etc.)
ex: emus and ostriches, or Grand Canyon squirrels
67
ecological isolation
populations live in different habitats in the same range or area
ex: crayfish
68
temporal isolation
populations not reproductive or active at the same time
ex: hawks (diurnal) and owls (nocturnal)
69
behavioral isolation
different behaviors don’t attract mates
ex: different mating calls
70
three general outcomes of natural selection
directional selection
stabilizing selection
disruptive selection
71
smallest biological unit that can evolve
population
72
half-life
time it takes half the radioactive amount to decay
each half-life cuts amount of radioactive material in half
73
evidence for evolution
```
radiometric dating
fossil record
morphological evidence
embryological evidence
experimental evidence
DNA evidence
```
74
half-life of Carbon
5730 years
75
punctuated equilibrium
long evolutionarily static periods punctuated by shorter periods of rapid evolution
76
sympatric speciation
organisms live in the same geographic area but are still reproductively isolated
ex: polyploidy in plants, where plants possess multiple sets of chromosomes and are unable to reproduce with other populations, but instead self-fertilize
77
mechanical isolation
when organisms are physically incompatible (“lock and key” model)
78
gamete isolation
sperm and egg incompatible
79
hybrid infertility
offspring infertile
80
stages of whale evolution
1. Pakicetus (53 mya)
2. Ambulocetus (50 mya)
3. Rodhocetus (47 mya)
4. Basilosaurus (38 mya)
5. Dorudon (33 mya)
6. Squalodon (14 mya)
81
characteristics of Pakicetus
terrestrial rat dog
82
characteristics of Ambulocetus
also terrestrial, but now swims in shallow water
83
characteristics of Rodhocetus
a. entirely aquatic
b. back feet shrink until they can’t support weight
c. nostril begins migration to top of head
d. eyes on side of head
84
characteristics of Basilosaurus
a. vestigial back legs
| b. much longer and sleeker body
85
characteristics of Dorudon
a. even more streamlined
| b. tail flukes start to develop
86
characteristics of Squalodon
development of echolocation in dolphin branch and baleen in some whales
