Term
| What is incomplete dominance? |
|
Definition
blending of parental traits produces a third phenotype
e.g. cross a red flower with a white flower, and produce a pink flower |
|
|
Term
| Roaning in horses and cows is an example of.... |
|
Definition
| co-dominant gene expression |
|
|
Term
|
Definition
| When more than one gene contributes to phenotype, in a way which is not merely additive. |
|
|
Term
| Is epistasis reflected in the phenotype or genotype? |
|
Definition
|
|
Term
| What allele produces black pigment in horses? Red? |
|
Definition
|
|
Term
|
Definition
| Mutations in different genes (and therefore different loci) which produce the same phenotype |
|
|
Term
| If one gene affects multiple tissues, this is an example of... |
|
Definition
|
|
Term
True or False
Lavender foal syndrome in horses, and deafness associated with merle colouring in Australian shepherds, are examples of the mimicking effects of genes |
|
Definition
false
pleiotropy
Both of these diseases are an example of a single mutation/gene which affects multiple different tissues |
|
|
Term
| Is threshold level of a trait a parameter of the population or the individual? |
|
Definition
|
|
Term
| Is liability a parameter of the population or the individual? |
|
Definition
|
|
Term
|
Definition
| the level of liability of a trait, above which all animals in the population will show the trait |
|
|
Term
|
Definition
individual variability in the degree to which a phenotype is expressed.
e.g. polydactyly in cats is controlled by one gene. It will always cause cats with this gene to have extra toes. But some cats will have more toes than others. |
|
|
Term
| What is incomplete penetrance |
|
Definition
If less than 100% of the individuals with the genotype, express the corresponding phenotype.
e.g. If a gene is known to cause a disease in only 70% of the population who has that gene, then it only has 70% penetrance |
|
|
Term
|
Definition
| A result of interaction between genotype and environment. In some instances, environment can compensate for poor genotype, or vice-versa. |
|
|
Term
|
Definition
The degree of correlation between genotype and phenotype.
H^2 = Vg / (Vg + Ve)
Variance of genotype divided by variance of phenotype |
|
|
Term
| In horses, E produces ____ pigment while e produces ____ pigment |
|
Definition
|
|
Term
|
Definition
| when a single gene affects multiple tissues |
|
|
Term
| Pleiotropy is often due to _____ and associated with neural signs |
|
Definition
| neural crest cell migration |
|
|
Term
True or False
Polygenic traits are often controlled by multiple genes |
|
Definition
|
|
Term
| Define incomplete penetrance |
|
Definition
| <100% of the genotype expresses the phenotype |
|
|
Term
| KNOW THE FLOWCHART FOR THE 5 LEVELS OF GENE CONTROL!!! |
|
Definition
-transcription
-RNA processing
-RNA transport
-translation
-post translational modification |
|
|
Term
|
Definition
| a blueprint copy of a strand of DNA, with Uracil replacing Thymine |
|
|
Term
| How does translation work? |
|
Definition
-mRNA + ribosomal subunits form a complex
-tRNA has anticodons which match mRNA codons
-tRNA transports AA's, associates with ribosome complex, AA's form peptide bond with mRNA
-protein chain forms 1 pair at a time, moving to the right
-ribosome unit moves one step along, repeat! |
|
|
Term
| After transcription, nuclear RNA is spliced. During this process, (introns/exons) are removed while (introns/exons_ form messenger RNA. |
|
Definition
introns removed
exons form messenger RNA |
|
|
Term
| What is the universal 'start' codon in mRNA? What does it code for? |
|
Definition
|
|
Term
| What are the primary stop codons in mRNA? |
|
Definition
|
|
Term
| What defines a genetic mutation? |
|
Definition
| uncorrected mistakes in DNA (NOT RNA) which alter the DNA sequence |
|
|
Term
| What is the difference between somatic vs germ-line mutations? |
|
Definition
somatic mutations affect on individual (not a population), and may be advantageous or disadvantageous
germ-line mutations are associated with meiosis, and therefore hereditary. They will affect a larger population |
|
|
Term
|
Definition
affect a single base pair
e.g. insertions/deletions/substitutions |
|
|
Term
| What are splice mutations? |
|
Definition
| when mutations result in introns being left in the mRNA |
|
|
Term
| A point mutation in which A is exchanged for G, or T for C |
|
Definition
| transition (A & G are purines, T & C are pyrimidines) |
|
|
Term
| What nucleic acids are purines? |
|
Definition
|
|
Term
| What nucleic acids are pyrimidines? |
|
Definition
|
|
Term
| A point mutation in which A is exchanged for C, or G for T |
|
Definition
|
|
Term
| What are the possible outcomes of a point mutation? |
|
Definition
Mis-sense (protein with a new AA sequence)
Nonsense (premature stop codon, or the protein isn't even coded for at all)
Silent (redundant codon copy, so it codes for the same AA and the same protein is produced) |
|
|
Term
| Lavender foal syndrome is a result of what type of mutation? |
|
Definition
| frameshift (change in the reading frame) mutation in MYO5A |
|
|
Term
|
Definition
| variations at a single position in a DNA sequence among individuals, resulting in 'alleles' if the SNP occurs in gene regions of DNA |
|
|
Term
| When would it be particularly advantageous to have a lot of SNP's within a gene region? |
|
Definition
| immune-related proteins (will result in a more robust population/immune system) |
|
|
Term
| What effect does methylation of DNA have? |
|
Definition
| -nucleosomes pack tightly together so TF's can't bind to the DNA and the genes are not expressed |
|
|
Term
| What role does acetylation have on epigenetic control? |
|
Definition
| When an acetyl group is added to a histone tail, the nucleosomes become more loosely packed. transcription factors can then bind and the genes are expressed |
|
|
Term
|
Definition
Happens in individuals with 2 x chromosomes (females, or kleinfelter males)
-in embryo, one of the X chromosomes in each cell is randomly inactivated
-usually 50% will express the mother's X chromosome, 50% will express the father's X |
|
|
Term
|
Definition
-only one allele is expressed, and the other one (imprinted one) is silenced
-the gene that comes from the father will act differently than the one that comes from the mother |
|
|
Term
|
Definition
| male donkey X female horse |
|
|
Term
|
Definition
| female donkey X male horse |
|
|
Term
True or False
All oocytes have the same number of mitochondria |
|
Definition
|
|
Term
| In the case of mitochondrial diseases, if an individual carries the gene, did it come from the mother or the father? |
|
Definition
| mother (it's always the mom that supplies mitochondria via her oocytes) |
|
|
