Card Set Information
Two genetic theories
Blending and particulate
A type of inheritance where each determinant is physically distinct and remains intact during fertilization
An observable physical feature
A form or character
The type of breeding mendel worked with
When plants all mated with the same trait and charater.
Order of generations
P > F1 + F1 = F2
In mendels experiments, what was a recessive trait
When it disappeared in F1 generation and reappeared in F2.
The trait that appears from P to F1 is
Which theory did mendel support
Particulate. He rejected blending
The ratio of dominant traits to recessive traits in F2
Mendel proposed that determinants occur in ______; and are segregated in the ______.
True breeding pairs have two copies of same allele; that is, they are
Homozygous for the allele.
Mendels first law
Law of segregation
Law of segregation
States that two copies of a gene separate when an individual makes gametes; each receives one copy.
A short sequence on a longer DNA molecule
The kinds of molecules that make up chromosomes
Mendels second experiment involved
Crossing peas that differed in two characters. Shape and color of seed.
Mendels second experiment was known as
A dihybrid cross
When alleles maintain associations seen in parental generation,
They could be linked.
If alleles are independent, gametes could be
In equal numbers
Mendels second law
Law of independent assortment
Law of independent of assortment
Alleles of different genes assort independently during formation. Chromosomes segregate independently.
Probability that both will happen (joint probability)
Multiply probabilities together.
Genetics use pedigrees to determine
Whether a rare allele is dominant or recessive
Pattern or inheritance for a rare dominant allele.
Every person with abnormal phenotype has affected parent; all (homozygous) or half (heterozygous) of offspring are affected when parent is affected.
Pattern of inheritance for a rare recessive allele
Affected people have two unaffected parents; ¼ of children of unaffected parents are affected.
Rare, stable, inherited changes in genetic material
A gene with wild type allele that is present less than 99% of time is
Two alleles of a gene produce phenotypes that are both present in heterozygote
Phenotypic expression of a gene is influenced by another
A cross between two different true breeding homozygoes. Can result in super offspring
Hybrid vigor; heterosis
Traits that are measured rather than assessed qualitatively
What two factors determine phenotype of an organism.
Genotype and environment
The proportion of individuals with a certain phenotype that SHOW the phenotype
The degree to which genotype is expressed in an individual
A particular site on a chromosome
This can alter a genes pattern of inheritance
Genetic linkage was discovered by
Thomas Hung Morgan
This drosophilia melanogaster is known as model organism because
Size, ease of breeding, and shot generation time
In THMs experiments, he saw that some ratios violated law of independent assortment. Instead
They were inherited together.
Morgan theorized that
Loci linked on same chromosome and could assort independently.
Some offspring showed phenotypes different from their parents.. meaning
They were recombinant phenotypes.
How do recombinants happen?
Two chromatids of four recombine.
How to measure recombinant frequencies
Number of recombined offspring / total number of offspring
Recombinant frequencies can be used to
Make genetic maps showing the arrangement of genes along chromosomes.
Recombinant frequencies are converted to
Map units which can be used to measure distances between genes.
How many pairs of chromosomes does the fruit fly have
3 pairs of autosomes and one pair of sex chromosomes.
Which chromosomes dont follow Mendelian patterns?
Male sex chromosomes are
Inheritance of a gene that is carried on a sex chromosome
4 facts about x-linked recessive phenotypes
Common in males, male can only pass to daughters, daughters who receive one are heterozygous carriers, mutant phenotype can skip a generation if it passes from male, to daughter, to her son.
Other than the nuc, where else are genes found
Mitochondria and plastids
Who are mitochondria and plastids inherited from
How do bacteria exchange genes?
A projection that initiates contacts between cells
How does bacterial conjugation work?
Donor fragments and some material enters recipient cell
Small circular DNA molecules next to the main chromosome that some bacteria have
Categories of genes on the plasmids
Metabolic tasks, conjugation, antibiotic resistance
Plasmids have the ability to
Move between cells at conjugation, replicate independently of main chromosome and add their genes by the recipients genome.