Chapters 17, 20, & 22 Flashcards
(123 cards)
1
Q
How many genes are in the human body?
A
Roughly 25,000
2
Q
Each gene carries instructions for how many proteins?
A
One
3
Q
What are the steps a cell goes through to produce a protein?
A
Transcription and translation
4
Q
Transcription
A
The code on the DNA is copied to mRNA.
5
Q
Who won the 2006 Nobel prize for chemistry?
A
Roger Kornberg who worked out the details of transcription
6
Q
Translation
A
The mRNA code is read by ribosomes in the cytoplasm, which join amino acids together.
7
Q
The code on DNA and mRNA is what kind of code?
A
A triplet code. 3 bases code for 1 amino acid.
Eg. GGA codes for glycine.
8
Q
What is AUG ok mRNA?
A
The start code.
9
Q
What is an example of a stop code on mRNA?
A
UGA
10
Q
What do transfer RNAs do? (tRNA)
A
Bring each amino acid to the ribosome.
Each tRNA had an anticodon which matches the 3 base codon on mRNA. The ribosome moves along the mRNA strand, adding amino acids one at a time
11
Q
What does anticodon on tRNA do?
A
Matches 3 base codon on mRNA. The ribosome moves along the mRNA strand, adding amino acids one at a time.
12
Q
How can small pieces of “interfering RNA” be used medically?
A
To switch off particular genes. Ex. To cure cancer or genetic diseases.
13
Q
Who won the 2006 Nobel prize for medicine?
A
The two scientists who discovered RNA interference.
14
Q
What do genes in eukaryotic cells have?
A
Introns, which do not code for proteins “junk DNA” and exons, which code for proteins.
15
Q
Introns
A
Do not code for proteins
16
Q
Exons
A
Code for proteins.
17
Q
Do some introns have some function?
A
Probably, so they are not really “junk”
18
Q
What are mutations?
A
Changes in the DNA code, can cause a different protein to be made.
19
Q
Are mutations harmful?
A
Usually, for ex. Cancer, but they occasionally produce a better protein than the original, which is important in evolution.
20
Q
What is gene sequencing?
A
Working out the exact order of bases in DNA.
21
Q
Gene sequencing: 1977
A
Genes of a virus were sequenced (5,400 base pairs)
22
Q
Gene sequencing: 1995
A
Genes of the bacteria Haemophilus sequenced: 1.8 million base pairs.
23
Q
Gene sequencing: 1998
A
Genes of the nematode worm sequenced: 100 million base pairs.
24
Q
Gene sequencing: 2002
A
Genes of rice were sequenced
25
Gene sequencing: 2005
Genes of a chimp were sequenced.
26
The human genome project is working on
Human genes
27
The human genome had how many base pairs?
3 billion
28
When was the human genome project completed?
2003
29
What did the new phase involve?
Producing a detailed map.
30
What will the human genome project be useful for?
Predicting and treating disease.
31
What are restriction enzymes?
They cut DNA at a specific site, with a particular DNA sequence.
32
Restriction enzymes exist ______ in bacteria
Naturally
33
How long have restriction enzymes been used and for what?
Since the 1960s to move genes from one species to another.
34
What does moving genes from one species to another produce?
Genetically modified plants or animals.
35
What is genetic modification used for?
To improve crops, ex. Adding a gene for vitamin A to rice.
36
What percent of corn and Cotten grown in the US are GM?
Roughly 80%
37
Pigs are being produced with
Healthy omega-3 fats.
38
Potential problems with GMs?
GM crops that contain natural insecticide Bt may kill beneficial insects such as butterflies. Also GM products contain new proteins, so may produce allergic reactions in some people.
39
Apart from agriculture, what else is increasingly using biotechnology?
Industry
40
What does RFLP analysis do?
It cuts DNA into fragments with restriction enzymes, that separates the fragments with electrophoresis. This makes a genetic fingerprint.
41
When was RFLP analysis invented?
In 1978
42
What does RFLP stand for?
Restriction Fragment Length Polymorphism
43
What can DNA be extracted from for RFLP analysis?
Skin, blood, hair, sperm, saliva, ect.
44
What is RFLP used for?
It is used in paternity cases to prove that someone is the father, or in murder and rape cases, or o identify bones.
45
When was RFLP first used in murder or rape cases?
In Florida in 1988.
46
In criminal cases RFLP analysis can be used to prove that someone is
Innocent or guilty.
47
RFLP can be used to identify bones example
When soldiers are killed in battle. New recruits now have to give blood or cheek cell samples
48
Genetic dog tags in the military?
Blood or cheek cell samples to identify them
49
When was RFLP analysis used to identify bones?
In 1994 to identify bones or the Russian royal family.
50
Polymerase chain reaction (PCR)
Uses DNA polymerase to make copies of DNA.
51
When is PCR used?
Before RFLP analysis.
52
When and by who was PCR invented?
1989 by Kary Mullis.
53
What does PCR allow crime investigators to do?
Get a DNA fingerprint from a single hair or drop of blood.
54
What are plasmids?
Circles of DNA from bacteria. They can be removed, altered, and put back into bacteria so bacteria make new proteins.
55
What is genetic engineering?
When plasmids are removed and altered, then put back into the bacteria so the bacteria make new protein.
56
Examples of genetic engineering?
Human growth hormone and insulin.
57
How was insulin previously made?
It was extracted from human blood, which ran the risk of accidentally transmitting viruses.
58
How is insulin produced now?
Safely from genetically engineered bacteria.
59
What is gene therapy?
Genes can be inserted into cells using retroviruses.
60
What potential does gene therapy have?
Can cure genetic diseases.
61
What is the main problem with gene therapy?
Getting human cells to accept and use new DNA.
62
When did gene therapy first work?
In 2000
63
What can gene therapy be used for besides treating genetic diseases?
To boost the immune system, ex. To treat cancer.
64
Hybridization
A radioactive molecule with a particular sequence of bases (a probe) is added to chemicals. The probe joins to or hybridizes with specific sequences.
65
What is hybridization used for?
To pick out particular molecules, ex genes or proteins.
66
Hybridization; Southern blot
Uses DNA probe to find DNA sequences. Named after its inventor, Edward southern.
67
Hybridization: northern blot
Uses RNA probe to find mRNA
68
Hybridization: western blot
Detects protein bands.
69
Cloning
Produced an exact genetic copy of an individual. Some plants and animals clone themselves naturally.
70
What plants clone themselves naturally?
Grass plugs, banana, hydra (?)
71
How does artificial cloning work?
The nucleus of the cell to be cloned is inserted into the cytoplasm of another cell.
72
What animal was the first to be artificially cloned?
A sheep named dolly in 1997. Dolly died young.
73
What would cloning be useful for?
Copying domestic animals with useful genes
Could help increase the population of an endangered species, or possibly revive extinct species
Copying genetically modified animals
Human cloned cells could be used to cure diseases. (Therapeutic cloning)
74
What does therapeutic cloning mean?
Taking the DNA from the cells of a patient and using stem cells to grow new tissue.
75
What are stem cells?
Cells that divide rapidly to produce new cells.
76
Why are stem cells important?
They are important in growth and repairing damaged areas.
77
Adult stem cells, ex bone marrow, can form
A limited number of types of cells
78
Stem cells from umbilical chords can form
A larger variety of cells.
79
Stem cells from embryos can form
Into any cell in the body. Usually harvesting the stem cells kills the embryo, but a new technique allows the embryo to survive.
80
What could stem cells be used for?
Curing many diseases, such as Alzheimer's disease.
81
Linnaeus (1760s)
Biologist. He invented the modern system of biological classification.
82
Who invented the modern system of biological classification?
Linnaeus.
83
Hutton (1795)
Geologist. He proposed the slow, gradual change altered the landscape, eg, rivers eroding mountains. Later Darwin applied this idea of slow, gradual change to living species.
84
Who proposed that slow, gradual changes altered the landscape?
Hutton
85
Malthus (1800)
Minister. Said that the human population will grow until limited by disease, starvation
86
Who said that the human population will flew until limited by disease, starvation?
Malthus
87
Lamarck (1810)
Biologist. He said that evolution was caused by passing on characteristics acquired during life. Ex, ppl who work out a lot will have babies born with large muscles.
88
Who said that evolution was caused by passing on characteristics acquired during life?
Lamarck
89
Lyell (1830)
Geologist. Calculated that the earth was millions of years old at least, rather than the 6,000 years that creationists believed.
90
Who calculated that the earth was millions of years old?
Lyell.
91
Who developed the theory of evolution?
Charles Darwin and Alfred Wallace.
92
Darwin and Wallace's theory of evolution
1) all species can rapidly increase in population if their young survive
2) most wild populations are stable over time
3) the reason populations do not normally increase is that resources are limited so there is struggle for survival
4) individuals in a population vary
5) most of this variation is inherited
93
Conclusion of theory of evolution
Individuals who are the best adapted will survive and reproduce, ones who are less adapted will die. Darwin and Wallace called this natural selection. Later the term "survival of the fittest" was used.
94
Evidence for evolution
```
Fossils
Biogeography
Comparative anatomy
Comparative embryology
Molecular biology
Vestigial organs
Atavisms
Imperfect "design"
New species have evolved recently
```
95
DNA contains the instructions for making what?
All the proteins in the body.
96
Evo evidence: fossils
Show how species have changed over time
A) the oldest fossils show no modern species
B) particular groups can be studied: ex modern horses evolved from hyracotherium a small leaf eating mammal with four toes
C) intermediate fossils connect different groups. Ex archaeopteryx links birds to reptiles
97
Evo evidence: biogeography
Particular species are only found in certain areas. Islands often have unique species: ex Hawaii- over 300 unique species. Madagascar- lemurs are only found here. Florida- Key deer in Florida keys.
98
Evo evidence: comparative anatomy
All vertebrates have the same arm bones. There are many similarities in their skeletons, muscles, organs.
99
Evo evidence: comparative embryology
Vertebrates embryos are all similar, with gill slits and a tail.
100
Evo evidence: molecular biology
Closely related species have similar DNA and proteins.
101
Evo evidence: vestigial organs
Have no function but are inherited rom an ancestor where they did have a function: ex pelvic bones in snakes. Also, appendix, third eyelid, muscles to move ears in humans
102
Evo evidence: Atavisms
Gene from ancestors that are usually switched off can be switched on. Ex. Horses with 3 toes. Humans with dense hair all over the face "werewolf gene"
103
Evo evidence: imperfect "design"
An organism just needs to survive long enough to reproduce, it is not a perfect design. Ex. Legs longer than neck in a giraffe. The human skull is made of several bones joined together. The human eye had nerves in front of the retina.
104
Evo evidence: new species
Have evolved recently. Ex spartina cordgrass in Europe. Primula kewensis in 1920s. HIV evolved in about 1940. Just in a few months in 2009 studies have shown evolution in bacteria and demonstrated one species splitting into two new ones in butterflies, beetles, and birds.
105
How old are the oldest human fossils?
Roughly 6 to 7 million years old
106
More than 4 million years ago Ardipithecus in Africa had a mixture of
"Primitive" and "derived" characteristics
107
What does primitive mean?
More ape-like
108
What does derived mean?
Human-like
109
When did Australopithecus evolve?
Roughly 4 to 2 million years ago
110
Where was Australopithecus found?
Africa
111
Compare Australopithecus with chimp
Slightly larger than modern chimp but walked on two legs
112
When did the genus homo evolve?
About 2 million years ago
113
Homo habilis
Used stone told
Was about 5 ft tall
Had small brain
Only found in Africa
114
Homo erectus
Used tools and fire
Roughly 6 ft tall
Larger brain
Spread from Africa to Asia and Europe
115
Where may modern humans and homo erectus come in contact?
Asia
116
Homo neanderthalensis
Largest brain of any human
Buried their dead
We're hunters, living mainly on large mammals
Cooked their food
117
DNA studies show that Neanderthals and Homo sapiens lived in the same areas but did not
Normally interbreed
118
In 2004, in Flores, Indonesia
A new species of human were found
119
Homo floresiensis
Found in 2004 in Flores, Indonesia
| Were smaller than pygmies but hunted large mammals and cooked their food
120
Homo sapiens
Spread worldwide
Only surviving human species
Modern humans all come from a small population who moved out of Africa less than 100,000 years ago.
121
Hunter-gatherers
Hunted animals and collected fruit, berries, and shellfish.
122
When did humans start growing crops?
About 10,000 years ago
123
From about 100,000 years to ago to 30,000 years ago there were how many species of human on the planet?
4
