Chapter 13 Flashcards
What is selective breading?
A modification that allows only those organisms with desired characteristics to produce the next generation.
What Hybridization?
The crossing of dissimilar individuals to bring together the best of both organisms.
True or false? Hybrids are often hardier than either of the parents.
True
What is inbreeding?
The continued breeding of individuals with similar characteristics.
True or false. Little problems can result from excessive inbreeding.
False. Serious genetic problems can result.
How can breeders increase the mutation rate?
By using radiation and chemicals. Although mutations usually occur spontaneously.
What do scientist get out of from mutations?
Introducing mutations has allowed scientists to develop hundreds of useful bacterial strains.
What is polyploidy?
When cells have double or triple the normal number of chromosomes.
When is polyploidy good?
Only in plants. It produces new species of plants that are often larger and stronger. Polyploidy is usually fatal in animals.
What is genetic engineering?
It is when biologist make changes in the DNA code of a living organism.
How can DNA be extracted?
By simple chemical procedures (like we did in the lab).
What does a restriction enzyme do?
It cuts a DNA sequence only if it matches the sequence exactly.
What is Gel electrophoresis?
It is when DNA fragments are placed at one end of a porous gel, and a electric voltage is applied to the gel. When the power is turned on, the negatively charged DNA molecules move toward the positive end of the gel.
What can gel electrophoresis be used for?
It can be used to compare the genome of different organisms or different individuals.
What does knowing the sequence of an organism’s DNA allows researches to do?
It allows researches to study specific genes, to compare them with the genes of other organisms, and try to discover the functions of different genes and gene combinations.
True or false: Short sequences of DNA can be assembled using DNA synthesizers.
True. Also, Synthetic sequences can be joined to natural sequences using enzymes that splice DNA together.
What is recombinant DNA?
Enzymes that make it possible to take a gene from one organism and attach it to the DNA of another organism.
What is Polymerase chain reaction or PCR?
A technique that allows biologist to make copies of genes.
What happens during Polymerase chain reaction or PCR?
DNA is heated to separate its two strands, then cooled to allow the primers to bind to single stranded DNA. DNA polymerase starts making copies of the region between primers.
What happens during transformation?
A cell takes DNA from outside the cell.
What is a Plasmid?
A small circular DNA molecule. They are found naturally in some bacteria and have been useful for DNA transfer.
What is a genetic marker?
It is a gene that makes it possible to distinguish bacteria that carry the plasmid and foreign DNA from those that don’t.
What is a Transgenic Organism?
An organism described as transgenic, contains genes from other species.
What has transgenic bacteria been useful for?
Insulin, growth hormone, and clotting factor.
