BDOL Interactive Chalkboard

1
(No Transcript)
2
Section 13.1 Summary pages 337 - 340
Selective Breeding

• From ancient times, breeders have chosen plants
  and animals with the most desired traits to serve
  as parents of the next generation.

• Breeders of plants and animals want to be sure
  that their ___________ breed consistently so that
  each member shows the ___________ trait.

3
Section 13.1 Summary pages 337 - 340
Selective Breeding

• The process of selective breeding requires time,
  patience, and several generations of offspring
  before the desired trait becomes ________________
  in a population.

• Increasing the frequency of desired alleles in a
  population is the __________ of genetic
  technology.

4
Section 13.1 Summary pages 337 - 340
Inbreeding develops pure lines

• To make sure that breeds consistently exhibit a
  trait and to eliminate any undesired traits from
  their breeding lines, breeders often use the
  method of inbreeding.

• _______________ is mating between closely related
  individuals. It results in offspring that are
  homozygous for most traits.

5
Section 13.1 Summary pages 337 - 340
Inbreeding develops pure lines

• Inbreeding can bring out harmful, recessive
  traits because there is a greater chance that two
  closely related individuals both may carry a
  ______________recessive allele for the trait.

6
Section 13.1 Summary pages 337 - 340
Inbreeding develops pure lines

• Horses and dogs are two examples of animals that
  breeders have developed as _____ breeds.

7
Section 13.1 Summary pages 337 - 340
Hybrids are usually bigger and better

• A hybrid is the _________ of parents that have
  different forms of a trait.

• Hybrids produced by crossing two purebred plants
  are often larger and stronger than their
  ________________

8
Section 13.1 Summary pages 337 - 340
Hybrids are usually bigger and better

• Many crop plants such as wheat, corn, and _____,
  and garden flowers such as roses and dahlias have
  been developed by hybridization.

9
Section 13.1 Summary pages 337 - 340
Determining Genotypes

• The genotype of an organism that is homozygous
  recessive for a trait is obvious to an observer
  because the recessive trait is ___________

• However, organisms that are either homozygous
  dominant or heterozygous for a trait controlled
  by Mendelian inheritance have the same
  _____________

10
Section 13.1 Summary pages 337 - 340
Test crosses can determine genotypes

• One way to determine the genotype of an organism
  is to perform a _________ cross.

• A test ________ is a cross of an individual of
  unknown genotype with an individual of known
  genotype.

• The pattern of observed phenotypes in the
  offspring can help determine the unknown genotype
  of the ________________

11
Section 13.1 Summary pages 337 - 340
Test crosses can determine genotypes
What are the possible results of a test cross?

• If a known parent is homozygous recessive and an
  unknown parent is homozygous dominant for a
  trait, all of the offspring will be heterozygous
  and show the ___________ trait.

12
Section 13.1 Summary pages 337 - 340
Test crosses can determine genotypes

• If the organism being tested is heterozygous, the
  expected 11 phenotypic ratio will be observed.

• If any of the offspring, have the undesired
  trait, the parent in question must be
  ________________.

13
Section 13.1 Summary pages 337 - 340
?
x
dd
Test crosses can determine genotypes
Homozygous x Homozygous
dd
Heterozygous x Homozygous
dd
DD
Dd
d
d
d
d
Dd
Dd
Dd
Dd
D
D
Dd
Dd
d
D
dd
dd
Offspring all dominant
Offspring 1/2 dominant
1/2 recessive
Dd
Dd
Dd
dd
14
Section 13.2 Summary pages 341 - 348
Genetic Engineering

• Genetic engineering is a faster and more reliable
  method for increasing the frequency of a specific
  ___________ in a population.

• This method involves cuttingor cleavingDNA from
  one organism into small fragments and inserting
  the fragments into a host organism of the same or
  a different ________________.

15
Section 13.2 Summary pages 341 - 348
Genetic Engineering

• You also may hear genetic engineering referred to
  as recombinant (ree KAHM buh nunt) DNA
  technology.

• Recombinant DNA is made by connecting or
  recombining, _____________ of DNA from different
  sources.

16
Section 13.2 Summary pages 341 - 348
Transgenic organisms contain recombinant DNA

• Plants and animals that contain functional
  recombinant DNA from an organism of a different
  genus are known as transgenic organisms because
  they contain ____________ DNA.

17
Section 13.2 Summary pages 341 - 348
Transgenic organisms contain recombinant DNA

• The first step of the process is to isolate the
  foreign DNA fragment that will be _________.

• The second step is to attach the DNA fragment to
  a _____________

• The third step is the transfer into the host
  organism.

18
Section 13.2 Summary pages 341 - 348
Restriction enzymes cleave DNA

• To isolate a DNA fragment, small pieces of DNA
  must be cut from a _______________.

• There are hundreds of _________________ enzymes
  each can cut DNA at a specific point in a
  specific nucleotide sequence.

19
Section 13.2 Summary pages 341 - 348
Restriction enzymes cleave DNA

• The same sequence of bases is found on both DNA
  strands, but in opposite ___________.

• This arrangement is called a palindrome (PA luhn
  drohm). Palindromes are words or sentences that
  read the same ____________ and backward.

20
Section 13.2 Summary pages 341 - 348
Restriction enzymes cleave DNA

• Some enzymes produce fragments in which the DNA
  is cut straight across both strands.

• These are called __________ ends.

• Other enzymes, such as the enzyme called EcoRI,
  cut palindromic sequences of DNA by unzipping
  them for a ________ nucleotides.

21
Section 13.2 Summary pages 341 - 348
Vectors transfer DNA

• Biological vectors include viruses and plasmids.
  A plasmid, is a small ring of DNA found in a
  ______________ cell.

Click image to view movie
22
Section 13.2 Summary pages 341 - 348
Vectors transfer DNA

• Two mechanical _____________ carry foreign DNA
  into a cells nucleus.

• One, a micropipette, is inserted into a cell the
  other is a microscopic metal bullet coated with
  DNA that is shot into the cell from a gene
  _____________

23
Section 13.2 Summary pages 341 - 348
Insertion into a vector

• If a plasmid and foreign DNA have been cleaved
  with the same restriction enzyme, the ends of
  each will match and they will join together,
  reconnecting the plasmid ring.

• The __________ DNA is recombined into a plasmid
  or viral DNA with the help of a second enzyme.

24
Section 13.2 Summary pages 341 - 348
Gene cloning

• After the foreign DNA has been inserted into the
  plasmid, the recombined DNA is ___________ into a
  bacterial cell.

• An advantage to using bacterial cells to clone
  DNA is that they reproduce quickly therefore,
  millions of bacteria are produced and each
  bacterium contains hundreds of recombinant DNA
  __________________

25
Section 13.2 Summary pages 341 - 348
Gene cloning

• _____________ are genetically identical copies.

• Each identical recombinant DNA molecule is called
  a gene clone.

• Plasmids also can be used to deliver genes to
  animal or plant cells, which __________ the
  recombinant DNA.

26
Section 13.2 Summary pages 341 - 348
Gene cloning

• Each time the host cell divides it copies the
  recombinant DNA along with its own.

• The host cell can produce the protein encoded on
  the recombinant DNA.

• Using other _________, recombinant DNA can be
  inserted into yeast, plant, and animal cells.

27
Section 13.2 Summary pages 341 - 348
Gene cloning
Foreign DNA (gene for human growth hormone)
Recombined DNA
Cleavage sites
Recombined plasmid
Bacterial chromosome
E. coli
Plasmid
Human growth hormone
28
Section 13.2 Summary pages 341 - 348
Cloning of animals

• So far, you have read about cloning one gene.
  For decades, scientists attempted to expand the
  technique from a _______ to an entire animal.

29
Section 13.2 Summary pages 341 - 348
Cloning of animals

• Although their techniques are inefficient,
  scientists are coming closer to perfecting the
  process of ____________animals.

30
Section 13.2 Summary pages 341 - 348
Polymerase chain reaction

• In order to replicate DNA outside living
  organisms, a method called polymerase chain
  reaction (PCR) has been developed.

• This method uses _______ to separate DNA strands
  from each other.

• An enzyme isolated from a heat-loving bacterium
  is used to replicate the DNA when the appropriate
  nucleotides are added in a PCR ______________

31
Section 13.2 Summary pages 341 - 348
Polymerase chain reaction

• The _____________ repeatedly replicates the DNA,
  making millions of copies in less than a day.

• Because the machine uses heat to separate the DNA
  strands and cycles over and over to replicate the
  DNA, it is called a thermocycler.

32
Section 13.2 Summary pages 341 - 348
Sequencing DNA

• In DNA sequencing, millions of copies of a
  double-stranded DNA fragment are __________using
  PCR. Then, the strands are separated from each
  other.

• The single-stranded fragments are placed in four
  different test ___________, one for each DNA base.

33
Section 13.2 Summary pages 341 - 348
Sequencing DNA

• Each tube contains four normal nucleotides (A,C,
  G,T) and an enzyme that can catalyze the
  synthesis of a complementary ________.

• One nucleotide in each tube is tagged with a
  different fluorescent color.

• The reactions produce complementary strands of
  varying ______________.

34
Section 13.2 Summary pages 341 - 348
Sequencing DNA

• These strands are separated according to size by
  gel electrophoresis (ih lek troh fuh REE sus),
  producing a pattern of fluorescent ___________ in
  the gel.

• The bands are visualized using a laser scanner or
  UV ______________.

35
Section 13.2 Summary pages 341 - 348
Gel Electrophoresis

• Restriction enzymes are the perfect tools for
  cutting DNA. However, once the DNA is cut, a
  scientist needs to determine exactly what
  fragments have been _____________.

36
Section 13.2 Summary pages 341 - 348
Restriction enzymes

• Either one or several __________ enzymes is added
  to a sample of DNA. The enzymes cut the DNA into
  fragments.

DNA fragments
37
Section 13.2 Summary pages 341 - 348
The gel

• With a consistency that is firmer than dessert
  gelatin, the _________ is molded so that small
  wells form at one end.

Gel

• Small amounts of the fragmented DNA are placed
  into these _______

38
Section 13.2 Summary pages 341 - 348
An electric field
Power source

• The gel is placed in a solution and an electric
  field is applied making one end of the gel
  positive and the other end ___________.

Negative end
Positive end
39
Section 13.2 Summary pages 341 - 348
The fragments move

• The negatively charged DNA _________ travel
  toward the positive end.

Completed gel
Shorter fragments
Longer fragments
40
Section 13.2 Summary pages 341 - 348
The fragments move

• The smaller the fragment, the faster it moves
  through the __________.

• The smallest fragments move the farthest from the
  ____________.

41
Section 13.2 Summary pages 341 - 348
Applications of DNA Technology

• The main areas proposed for recombinant bacteria
  are in industry, medicine, and ___________________
  _____

Recombinant DNA in industry

• Many species of bacteria have been engineered to
  produce __________ compounds used by humans.

42
Section 13.2 Summary pages 341 - 348
Recombinant DNA in industry

• Scientists have modified the bacterium E. coli to
  produce the ______ indigo dye that is used to
  color denim blue jeans.

43
Section 13.2 Summary pages 341 - 348
Applications of DNA Technology

• The production of cheese, laundry detergents,
  pulp and paper production, and sewage treatment
  have all been enhanced by the use of recombinant
  DNA techniques that increase __________ activity,
  stability, and specificity.

44
Section 13.2 Summary pages 341 - 348
Recombinant DNA in medicine

• Pharmaceutical companies already are producing
  molecules made by recombinant DNA to treat
  ____________ diseases.

• Recombinant bacteria are used in the production
  of human growth ___________ to treat pituitary
  dwarfism.

45
Section 13.2 Summary pages 341 - 348
Recombinant DNA in medicine

• Also, the human gene for insulin is inserted into
  a bacterial plasmid by genetic engineering
  techniques. Recombinant bacteria ____________
  large quantities of insulin.

46
Section 13.2 Summary pages 341 - 348
Transgenic animals

• Scientists can study diseases and the role
  specific genes play in an organism by using
  transgenic _____________.

47
Section 13.2 Summary pages 341 - 348
Transgenic animals

• Mouse chromosomes also are similar to ___________
  chromosomes.

• Scientists know the locations of many _______ on
  mouse chromosomes.

48
Section 13.2 Summary pages 341 - 348
Transgenic animals

• The roundworm Caenorhabditis elegans is another
  organism with well-understood genetics that is
  used for transgenic studies.

• A third animal commonly used for transgenic
  studies is the _________.

49
Section 13.2 Summary pages 341 - 348
Transgenic animals

• On the same farm in ___________ that produced the
  cloned sheep Dolly, a transgenic sheep was
  produced that contained the corrected human gene
  for hemophilia A.

• This human gene inserted into the sheep
  chromosomes allows the production of the clotting
  protein in the sheeps _________

50
Section 13.2 Summary pages 341 - 348
Transgenic animals

• This farm also has produced transgenic sheep
  which produce a protein that helps lungs inflate
  and function ____________.

51
Section 13.2 Summary pages 341 - 348
Recombinant DNA in agriculture

• Recombinant DNA technology has been highly
  utilized in the agricultural and _______
  industries.

• Crops have been developed that are better
  tasting, stay fresh longer, and are protected
  from disease and _________ infestations.

52
Section 13.2 Summary pages 341 - 348
Recombinant DNA in agriculture
The Most Common Genetically Modified (GM) Crops
150
140
Millions of hectares
7
100
72
36
50
34
25
16
11
0
Soybeans
Corn
Cotton
Canola
53
Section 13.3 Summary pages 349 - 353
Mapping and Sequencing the Human Genome

• In 1990, scientists in the United States
  organized the Human Genome Project (HGP). It is
  an international effort to completely map and
  sequence the human __________, the approximately
  35 000-40 000 genes on the 46 human chromosomes.

54
Section 13.3 Summary pages 349 - 353
Mapping and Sequencing the Human Genome

• In February of 2001, the HGP published its
  working draft of the 3 billion base pairs of DNA
  in most human _______.

• The sequence of chromosomes 21 and 22 was
  finished by May 2000.

55
Section 13.3 Summary pages 349 - 353
Linkage maps

• The genetic map that shows the relative locations
  of genes on a chromosome is called a linkage map.

• The historical method used to assign genes to a
  particular human chromosome was to study
  _________ data from human pedigrees.

56
Section 13.3 Summary pages 349 - 353
Linkage maps

• Because humans have only a few ___________
  compared with the larger numbers of offspring in
  some other species, and because a human
  generation time is so long, mapping by linkage
  data is extremely inefficient.

• Biotechnology now has provided scientists with
  new methods of ___________ genes.

57
Section 13.3 Summary pages 349 - 353
Linkage maps

• A genetic marker is a segment of DNA with an
  identifiable physical _________ on a chromosome
  and whose inheritance can be followed.

• A marker can be a gene, or it can be some section
  of DNA with no known __________.

58
Section 13.3 Summary pages 349 - 353
Linkage maps

• Because DNA segments that are near each other on
  a chromosome tend to be inherited together,
  ___________ are often used as indirect ways of
  tracking the inheritance pattern of a gene that
  has not yet been identified, but whose
  approximate location is known.

59
Section 13.3 Summary pages 349 - 353
Sequencing the human genome

• The difficult job of sequencing the human genome
  is begun by ____________ samples of DNA into
  fragments using restriction enzymes.

• Then, each individual fragment is cloned and
  sequenced. The cloned fragments are aligned in
  the ______ order by overlapping matching
  sequences, thus determining the sequence of a
  longer fragment.

60
Section 13.3 Summary pages 349 - 353
Applications of the Human Genome Project

• Improved techniques for prenatal diagnosis of
  human disorders, use of gene therapy, and
  development of new methods of crime ___________
  are areas currently being researched.

61
Section 13.3 Summary pages 349 - 353
Diagnosis of genetic disorders

• One of the most important benefits of the HGP has
  been the diagnosis of genetic disorders.

62
Section 13.3 Summary pages 349 - 353
Diagnosis of genetic disorders

• The DNA of people with and without a genetic
  disorder is compared to find differences that are
  associated with the disorder. Once it is clearly
  understood where a gene is located and that a
  ____________ in the gene causes the disorder, a
  diagnosis can be made for an individual, even
  before birth.

63
Section 13.3 Summary pages 349 - 353
Gene therapy

• Individuals who inherit a serious genetic
  disorder may now have hopegene therapy. Gene
  ___________ is the insertion of normal genes into
  human cells to correct genetic disorders.

64
Section 13.3 Summary pages 349 - 353
Gene therapy

• Trials that treat SCID (severe combined
  immunodeficiency syndrome) have been the most
  ___________

• In this disorder, a persons immune system is
  shut down and even slight colds can be
  life-threatening.

65
Section 13.3 Summary pages 349 - 353
Gene therapy

• In gene therapy for this disorder, the cells of
  the immune system are removed from the patients
  bone _________, and the functional gene is added
  to them.

• The modified cells are then _____________ back
  into the patient.

66
Section 13.3 Summary pages 349 - 353
Gene therapy
Cell culture flask
Add virus with functioning SCID gene
Bone marrow cells
Gene
Bone marrow cell with integrated gene
Hip Bone
67
Section 13.3 Summary pages 349 - 353
Gene therapy

• Other trials involve gene therapy for cystic
  fibrosis, sickle-cell anemia, hemophilia, and
  other genetic disorders

• It is hoped that in the next ________ DNA
  technology that uses gene therapy will be
  developed to treat many different disorders.

68
Section 13.3 Summary pages 349 - 353
DNA fingerprinting

• DNA fingerprinting can be used to convict or
  acquit individuals of criminal offenses because
  every person is genetically __________.

• DNA fingerprinting works because no two
  individuals (except identical twins) have the
  __________ DNA sequences, and because all cells
  (except gametes) of an individual have the same
  DNA.

69
Section 13.3 Summary pages 349 - 353
DNA fingerprinting

• In a forensic application of DNA fingerprinting,
  a small DNA sample is obtained from a suspect and
  from blood, hair, _______, or semen found at the
  crime scene.

• The DNA, which includes the unique non-coding
  segments, is cut into fragments with
  ______________ enzymes.

70
Section 13.3 Summary pages 349 - 353
DNA fingerprinting

• The fragments are separated by _______
  electrophoresis, then further analyzed. If the
  samples match, the suspect most likely is guilty.