Midterm Exam Flashcards
What holds the key for biological complexity
Genes->Transcripts->peptides->phenotypes
What does genetics study
Heredity, the inheritance of genetic material and traits down generations
What is classical genetics
The study of how descriptive factors are passed down from one gene to the next
Why did mendel chose the garden pea
Easy to grow, short life cycle, and mating could ge controlled
Different varieties available
Used homozygous varieties
What were the 7 characters mendel studied
Round or wrinkled Yellow or green seed Purple or white petals Inflated or pinched pods Green or yellow pods Axial or terminal flowers Long or shorr stems
Mendels approach was important why
He designed each cross carefully and kept detailed records
Counted the number of offspring with traits
Kept track of generations
And made predictions
Difference between cross pollination and selfing
Cross pollination is from one flower to another flower
Selfing is pollination of the same flower
What are monohybrid crosses
Crosses of two varieties of true breeding plant that differed in only one character
Example: seed shape or seed colour
What is thr particulate theory of genetics
Genetic information comes as two seperate and independent particles where:
One particle can be dominant over the other
The combinatjon of these particles change in F1 and F2 plants
They are not combining they have different extremes: wrinkled and smooth
What is another name for address of genetic info
Locus: physical reguon in chromosomes where genes are
What is the term for particle in genetics
Gene: unit of hereditary information
Whag is the version of the particle yhat segregates
Allele: a version of a gene thag occupies a locus
What are two identical particles together
Homozygous : when both alleles of a gene are yhr same in a diploid organism
What are two different particles together
Heterozygous : when two alleles of a gene in a diploid organism differ
What is mendels hypthesis in modern terms
Alternative versions of a gene account for variation
Organisms inherit 2 alleles one from each parent
If two alleles are different one may be dominant
Each haploid gamete carriers one allele of given trait and the dominant allele determines the phenotype
What is mendels first law
Law of segregation : the recessive traits reappear in F2 generation the two alleles of the same gene segregate from eachother during germ cell formation
What are the predictions of mendels 1st law
- Reciprocal corsses should yield identical results: doesnt matter if its female or male gamete with dominant trait it should always give you 3:1 ratio in F2 generation
- Of the F2 generation 2/3 should be Yy and 1/3 should be YY
3 Gametes produces by a heterozygote should be Y or y in the ratio of 1:1
What is a test cross
Crossing a plant with unknown genotype to homozygous recessive parent
Which generation shows evidence for dominance
F1 - only has one potential phenotype and genotype
Which generation illistrates segregstion of alleles from F1 gametes
F2 generation - shows the most differentiation in genotypes
What is mendelians second law
Law of Independent Assortment: alleles of two or more genes segregate independently during transmission from parent to offspring
What does it mean if Chi Squared value is 0
It means that our data equals perfectly and that they are consisted with the mendelians hypothesis
If there are more rare phenotypes whag does that mean
It means that its possible the hypothesis is not correct or it isnt following this idea
How many chromosomes does a human have
23 pars (2n = 46) 22 autosomes and 1 pair of sex chromosomes
Whats the difference between rare and recessive
Recessive is the mode of inheritence and rare is how frequent it is in the population
What is a rigorous distinction
Dominant trait - unaffected parents cant have an affected child
Recessive trait - unaffected parents can gave an affected child
Any is non-rigorous criteria
Dominant trait - tends to appear in every generation
Recessive trait - tends to skip generations
