Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
LAT Certification
Chapter 8
| Question | Answer |
|---|---|
| What are chromosomes? | Long coiled strands of DNA |
| What are alleles? | Different versions of the same genes |
| What is genotyping? | Genetic testing |
| What is a homozygote? | When both genes of a pair are the same |
| What is a heterozygote? | When the genes of a pair are different |
| What is a wild type? | When an animal does not contain the allele of interest |
| If a gene is referred to as null, what is this? | When a gene is absent or turned off due to a mutation that block's the gene's expression |
| What is homozygous null? | Both copies of the gene are absent or turned off-gene produces no product and the animal is called a knockout |
| What is genetic engineering? | The science of manipulating the genetic makeup of a living organism |
| What are the types of targeted mutation? How do they differ? | Knockin-new genes are inserted Knockout-targeted mutation blocks the function of the gene |
| What is pronuclear injection? | Technique performed on a fertilized egg in a single-cell stage. Genes are injected with a tiny glass pipette directly into the cell. DNA is incorporated randomly into the chromosomes as they divide and the embryo develops |
| What is homologous recombination? | Embryonic stem cells are collected and used to produce embryonic stem (ES) cell lines-DNA is inserted into these cells by electroporation. Cells containing the mutated gene are then injected into another developing blastocyst |
| What is a chimera? | An animal with some of its cells containing the new gene and some without the new gene |
| What is the most common technique to determine genotype? | Polymerase chain reaction (PCR) |
| Describe the PCR process | A sample of tissue is taken, the tissue is dissolved and the mix is placed in a tube with an enzyme and short DNA fragments of the gene of interest, placed into PCR machine, which takes samples through cycles of heating and cooling, then amplification |
| What is gel electrophoresis? | How to visualize an amplified gene-electric current passed through gel, which separates the DNA into a column, can determine if an animal possesses the gene by where the bands accumulate |
| What is a phenotype? | How genes express traits; the measurable result of the genes and how they interact with the environment |
| What are the different categories of phenotypes? | Visual, behavioral, demonstrable, inducible, physiological |
| What are linked genes? | Genes that are located adjacent to one another on the same chromosome, and tend to be inherited together. |
| What is a mating system? | The method used to pair animals for mating |
| What is monogamous mating? | One female is bred with one male |
| What is polygamous mating? | Two or more females are bred with one male; females are removed from mating cage once they are determined to be pregnant |
| What is harem mating? | Two or more females are bred with one male; the group is kept together throughout pregnancies |
| What is intensive breeding? | When the male remains with the female or females continuously |
| What are some advantages to intensive breeding? | number of litters per female is maximized per unit of time, postpartum estrus, labor requirements are lower as animals are not removed from cage, recordkeeping is simplified |
| What are some disadvantages to intensive breeding? | Higher demand for space, necessitates more males in the colony, older litter must be weaned before the next litter is born to prevent overcrowding |
| What is nonintensive breeding? | When the stud male and females are housed separately while the females are rearing their young. The female will not mate again until the young are weaned |
| What are the advantages to nonintensive breeding? | Reduces the fighting between aggressive females, newborns cannot be killed by the male, there is greater control in timing litters |
| What are the disadvantages to nonintensive breeding? | labor costs may be higher as animals will have to be moved in and out of cages, no postpartum estrus, more care in recordkeeping to identify poor producers |
| Why is a timed mating system used? | To provide embryos or newborn mice at a precise date needed for experiments |
| What is the Whitten effect? | Initiating estrus in group housed females by adding a male to the cage |
| What is a breeding scheme? | The plan for producing a colony with a desired genetic makeup |
| What is outbreeding? | Breeding animals that are unrelated or only distantly related |
| Why are outbred stocks bred? | To maintain the genetic difference among the animals. Scheme often produces heartier offspring and larger litter sizes |
| What is inbreeding? | Producing animals with minimal genetic variation by brother-sister matings |
| What are the 3 distinct colonies used to establish an inbreeding colony? | Foundation, Expansion, Production |
| What is the foundation colony? | The original animals with the desired DNA |
| What is the expansion colony? | Expansion of the founders to ensure that the desired genetic trait will not be lost if anything happens to the founders |
| What is the production colony? | Animals actually used for research-bred from the expansion colony |
| What is hybrid breeding? | A selective system in which the parents are of different inbred strains-used to transfer a desired mutation from one to the other strain. Offspring are a mixture of the parents |
| What are recombinant inbred strains? | Hybrid breeding followed by brother/sister matings or inbreeding of the F1 and subsequent offspring |
| What is a coisogenic animal? | An inbred animal with a single mutation-that makes the animal different from the other animals. Ideal for studying effects of one gene |
| What are congenic strains? | They are constructed by selectively mating an animal carrying the mutation of interest to an inbred animal from a strain of choice-to fix the mutant gene in the genetic background of subsequent generations |
| What is artificial insemination? | Manually placing semen into the reproductive tract of a female in heat |
| What is in vitro fertilization? | Involves the union of eggs and sperm outside the body, and then implementing the resulting zygotes |
| What are the four stages of the estrous cycle? | Proestrus-eggs develop in ovary, Estrus-ovulation, Metestrus, Diestrus |
| What is anestrus? | The long period between breeding seasons in some animals |
| What is parturition? | Birth of the young at the natural end of gestation |
| What is a foster mother? | A lactating female that rears the young in place of the biological mother. |
| What conditions must be met in fostering situations? | -Total litter size must remain about the same to ensure mother has enough milk -foster pups should be close in age to the mother's own pups |
| What can variations in the macroenvironment do to a breeding colony? | Failure to copulate, Disruption of the estrous cycle ,abandonment of young, cannibalism |
| When should pups be weaned? | When they are capable of reaching food and water |
| How can the sexes be differentiated at time of weaning? | Anogenital distance-distance between the anus and the genital papilla-greater in males than in females |
| What is a recommended time frame for replacing breeders? | After about 9 months, or after female have had 6-7 litters |
| What is animal biosecurity? | All measures to control known or unknown infections in laboratory animals-methods should be in place to minimize risk of infecting established colonies and to deal with disease within the colony it is arises |
| What is rederivation? | Process used to clear a colony of infectious disease or to obtain an animal line from a facility where animals cannot be verified as SPF |
| What is cryopreservation? | To preserve a genetic line of some animals-freeze at very low temperatures embryos, sperm cells or ovaries |
| What is special about cats? | Polyestrous and will breed all year long, induced ovulators |
| What is special about rabbits? | Induced ovulators, no distinct estrous cycle; doe is always taken to the buck's cage-if not doe will attack buck |
| What is special about dogs? | Estrus occurs every 7-8 months in any season; spontaneous ovulation |
| What does farrowing mean? | In pigs ,means giving birth |
| What is special about ferrets? | Induced ovulators |
Created by:
CarrieAngeles
Popular Veterinary sets