chapter 15 - GENETIC ENGINEERING Flashcards
Genetic engineering is the process of _______
__ replacing specific genes in an organism so that the organism expresses a desired trait
Process of genetic engineering:
taking genes from one organism and placing them into another
genetic engineering can only occur when _____
when we know where genes occur on the specific chromosomes
we know where genes by looking at ______
gene maps and genomes
what do gene maps do?
show the location of genes on a chromosome
what are genomes?
all the genetic material in an organism
when did the human genome project begin?
1990
what did the human genome project do?
mapped the DNA sequence of human genes
how many nucleotides were sequenced?
3.3 billion
when was the human genome project completed?
2003
what are the 5 types of genetic engineering?
cloning, gene therapy, stem cell research, selective breeding, and hybridization
what is a clone?
an identical copy of a gene or entire organism
how do clones occur?
by nuclear transfer either naturally or may be engineered
how are organisms cloned?
by introducing a nucleus from a boy from a body cell into an egg cell to generate an organism identical to the nucleus of the donor
what is an example fo a cloned organism?
polly the sheep in 1996
benefits of genetic engineering
organ transplants, saving endangered species
drawback of cloning
genetic disorders + health problems
what is gene therapy?
the process of inserting a normal gene into an absent or abnormal gene
benefits of gene therapy
The inserted gene makes the correct protein, eliminating the cause of the disorder
drawbacks of gene therapy
It has had limited success because the hot often rejects injected DNA
what does gene therapy work best for?
works best for diseases with loss of a single protein, such as cystic fibrosis
what are stem cells?
undifferentiated cells that have the potential to become anything
benefits of stem cells
can replace tissue that is deficient due to disease or damage
drawbacks of stem cells
mostly found is embryos which can cause tumors, and bone marrow in adults
what are the hopes for future stem cells?
new induced stem cells hope to eliminate unethical use of embryos
what is selective breeding?
artificially breeding organisms with a desired trait
irl, what do we see that at a massive level that is the result of selective breeding?
almost all domesticated animals and crops
what is inbreeding?
crossing individuals that are closely related
benefits of inbreeding?
offspring tend to be stronger than either parent
what are the drawbacks of inbreeding?
offspring can have genetic complications if parents are too similar in variation
what is hybridization?
breeding organisms that show 2 traits in order to produce offspring that express both traits
where does hybridization occur?
in 2 species
benefits of hybridization?
offspring are often stronger and more fit than either of the parents
drawbacks of hybridization?
expensive and unnatural;
what is electrophoresis
a laboratory method that allows scientists to separate DNA, RNA, or proteins on a molecular size
how can electrophoresis be used at a crime scene?
you can take DNA from a crime scene and compose it to DNA of different suspects
what are SNPS
single nucleotide polymorphism - genetic variations where alleles vary in only a few nucleotides, doesn’t change phenotype
SNPs makes each _______
person unique
No 2 people (except identical twins) have _______
the same base sequences
what happens at the restriction site?
nucleotide sequences are recognized by the restriction enzymes
No 2 people will _____-
have the same lengths of fragments after they have been cut out
RFLP meaning?
restriction fragment length polymorphisms
in DNA sequence reading and duplicating process, what does electrophoresis do?
separates the fragments with electric currents and smallest fragments travel farthest, making a unique fingerprint
stage 1 of DNA testing
cells are broken down to release DNA
If only a small amount of DNA is available, it can be amplified using the PCR
what is PCR?
polymerase chain reaction, allows DNA sequencing/copying of fragments
what allows PCR to be fast?
it uses an enzyme (T. aq polymerase) which runs at high temps
stage 2 of DNA testing
The DNA is cut into fragments using restriction enzymes. Each restriction enzyme cuts DNA at a specific sequence
stage 3 of DNA testing
fragments are separated on the basis of size using a process called gel electrophoresis. DNA fragments are injected into wells and current electric is applied along the gel
DNA is negatively charged that is attracted to the positive end of the gel. The shorter DNA fragments move faster than the longer fragments
DNA is separated on the basis of size
examples of biological materials used for DNA testing
blood, body tissue cells, hair, salvia, vagina cells, semen or used condom
what are some societal impacts of genetic engineering?
I. the development of plants that make natural insecticides, higher in protein, and spoil more slowly
II. development of animals that are bigger, faster growing, resistant to disease
III. The development of bacteria that produce human insulin, HGH, golden rice to feed the world, and vaccines
IV. In humans, copies of normal genes transplanted into cells of people suffering from genetic diseases
What kind of mutation is sickle cell anemia?
point mutation
how does the mutation in sickle cell anemia affect amino acids?
mutation results in a substitution, in which normally a person would have valine, but the codon is instead replaced with glutamic acid
what kind of disease is sickle cell anemia?
autosomal recessive and incomplete dominant
what genotype is preferred in malaria affected places, what about non malaria?
In Malaria affected places in the world, it’s preferable to have the genotype Hbs/ HbA.
In non-Malaria affected places in the world, it’s preferable to have the genotype HbA/ HbA.
process explained
EcoRI is a common type of restriction enzyme, which scans the DNA for a specific part, and cuts it. Hydrogen bonds make them come back together again
Used to cut DNA
Gel electrophoresis is where there’s gel, a positive charge on one end, and negative on the other side, and DNA is pulled in the positive direction as it is negative, in order to measure the length of a DNA fragment.
PCR is used to make copies of it, in which a primer, a small section of DNA, and nucleotides and polymerase, heats and cools, while it heats, it breaks the hydrogen bonds, unzipping DNA. The primer bonds to it, and the polymerase then grabs on to it. Polymerase adds complementary letters, copying the DNA
