Intro Flashcards
4 Levels of Genetics and Vet Med
- Individual
- Family
- Herd/Flock
- Population
genetics
science of heredity and variations
Central Dogma
information is stored as DNA, converted to RNA through transcription, converted to protein through translation
Chromosome Structure
two sister chromatids joined together by a centromere, resulting in a short arm (p) and a long arm (q)
Metacentric
centromere is located somewhere in the middle of the chromosome
Acrocentric
centromere is somewhere near the end of the chromosome
Diploid Organisms
inherit one set of chromosomes from father, one set from mother (resulting in two copies of the genome)
of Chromosome Pairs in Cats
19
of Chromosome Pairs in Dogs
39
of Chromosome Pairs in Horses
32
of Chromosome Pairs in Donkeys
31
of Chromosome Pairs in Cattle
30
of Chromosome Pairs in Sheep
27
of Chromosome Pairs in Pigs
19
What is unique about the bird genome?
They have chromosomes (9) AND microchromosomes
Why are mules sterile?
Horses and donkeys have different numbers of chromosomes
Karyotype
visualization of chromosomes
Mitosis
cells replicate via mitosis, resulting in 2 diploid (2 copies of genome) daughter cells which are genetically identical
Meiosis
results in 4 haploid (1 copy of genome) daughter cells which are gentically different from parent cell and each other; how we get gametes
Phases of Mitosis/Meiosis
- Prophase
- Prometaphase
- Metaphase
- Anaphase
- Telophase
2 Ways in which we obtain Genetic Differences during Meiosis
- Chromosomal Reassortment
- Recombination (crossover)
What could a high number of mitotic bodies indicate?
possible cancer (because it’s mitosis gone wrong, no signal present to turn off)
Is mitotic rate consistent among cell types?
No - varies from 0.5%-40%
Gene
unit of inheritance; DNA sequence with a defined beginning and end (start/stop codons) which encodes a cellular product
Introns and Exons
introns of a gene get cut away and exons contribute to the protein product
When is a gene expressed?
when the protein it encodes is made
Are introns just junk?
No - they do have a lot of regulatory elements, but they still do not contribute to the protein product
If a gene is turned on, will it 100% be expressed (get a protein)?
no - due to regulation of gene expression
At what levels can gene expression be regulated?
transcription, translation, and post-translational modifications
Do all regulatory events stop gene expression?
no, some will decrease expression, but some will enhance/increase, divert, interupt, or change
Locus (loci)
location(s) of a gene along a chromosome
Homozygous
alleles identical
Heterozygous
alleles different
How many alleles at each locus?
2
How many alleles are inherited from each parent?
1
Genotype
representation of the alleles at any locus
(homo or hetrozygous)
of Genes in Mammals
20-25k
of Genes in Protozoa (single celled organisms)
10k
How do mammals get our genetic complexity?
Two-thirds of our known genes encode for more than one product
Alternative splicing
reading a gene in a different way to result in a different product; change the meaing by only reading pieces but still always reading in the same order
Phenotype
the observable characteristic or trait
Strength of Genotype-Phenotype Correlation
strong = changes in one gene result in obvious phenotypical changes (simple/Mendelian traits)
weak = can be due to multiple genes and/or environmental effects, difficult to predict
