Past test questions Flashcards
DNA
- is composed of 2 parallel chains bound together by strong sugar phosphate bonds
- is a polymer of nucleotide unites bound together, end to end by weak hydrogen bonds
- replicated prior to cell division during mitosis
Meiosis
- Meiosis II consists of division of haploid cells
- In the male, the result is 4 functional sperm cells
RNA
- mRNA carries the genetic information from DNA
- Is involved in both transcription and translation
Gene Linkage
- condition where allelic gene pairs consistently travel together through meiosis and syngamy
- crossing over involved the reciprocal exchange of chromosomes segments between homologs and may disrupt the linkage of two genes
- recombination involves new allelic pairings of genes
Hardy-Weinberg
- is an equilibrium law dealing with large random mating populations
- is a mathematical formula that describes genotypic frequencies in terms of phenotypes
Post-transcriptional RNA modifications includes
- addition of a 7-methyl guanosine cap
- Addition of poly-A tail to a primary transcript
- splicing of introns
In the hardy-weinberg equation, the term 2pq represents the frequency of the
-heterozygous
AaBb x aabb is an illustration of a
- dihybrid cross
- test cross
Benefits of alternative splicing includes
-generated different proteins from single gene
Stop codons included the following except
-UAU
The inheritance of scurs (small, moveable horn-like growths in cattle) is dominant in males and recessive in females
sex-influenced
Parents with normal vision (not color blind) produce daughters that have normal vision, but if the dam is a carrier, half of the sons will be color blind
sex-linked
An allele in horses gives rise to the overo-coat color pattern, which involves white primarily on ventral surfaces of the horse. Homozygosity for the overo allele result sin all white foals that suffer from aganginosis of the large intestine and die within a few days of birth
lethal
The three consecutive bases on the mRNA is a codon that specifies an amino acid. There are 64 codons in total and they code for the 20 amino acids?
genetic code
A situation where heterozygotes is superior to both homozygotes in performance or disease resistance?
overdominance
Xeoderma Pigmentosum in humans is controlled by a single autosomal gene. DD individuals are normal, Dd individuals have freckled skin, and dd individuals have freckled (especially the face) that ulcerates when exposed to UV light. The result is cancer of these areas which is fatal to these individuals before reproductive age
semi-lethal
The phenotypic effect of a gene at one locus is dependent on what allele is present at another locus
epistasis
Traits that are governed by genes on the autosomes and can only be expressed in one sex due to anatomical differences and have to penetrance or simple turned off in the other sex?
sex-limited
A relatively common form of congenital heart disease, conotruncal septum defecrs, found in keeshounds and can be divided into four different grades of increasing severity?
variable expersivity
Group of individuals within a species which potentially can interbreed and share a common gene pool?
population
If a strong negative change in mature weight is observed along with a strong postive change in meat tenderness then the two traits have a
-weak positive correlation
Which of the following is considered the most important genetic parameter for an individual?
breeding value
The degree of homozygosity in the offspring can be affected by
- genetic relationship of the parents
- the heritability value of the traits
Correlation
- the correlation of X and Y is the same as the correlation of Y and X
- correlation is unitless
- It only ranges from -1 to 1
In a non-random mating
-A and B only
(-expected proportion of homozygous and heterozygous individual deviates from HW)
(-Assignment of mate can be based on genetic relationship and phenotypic similarity)
Inbreeding depression
- oppostite of heterosis
- results from poor gene combination value
Byx
- is the regression of Y on X
- variation in trait X influences the variation in trait Y
- there is an assumption of cause and effect
Effects of outbreeding will depend on
- genetic relationships of the parents
- traits heritability
The following are examples of a major or extensive use of crossbreeding except
-crossing of two dairy breeds such as Holstein and Jersey
Environmental correlation
- measure of strength of relationship between environmental effects of one trait and another
- they are often used for management purposes
Heterosis
-A and C only
(-results from increased heterozygosity)
(-gene combinations are not transmitted to the progeny)