36 terms

Bio Genetics Quiz

Vencile's Honors Bio - Genetics/ DNA quiz
Bred pea plants to study how traits were passed on, came to 2 conclusions and 2 principles
Mendel's Conclusions
1. Always inherit a pair of genes that control a trait, one from each parent 2. A gene for a single trait comes in alternate forms called alleles- either dominant or recessive
Two different types of one gene - one is dominant the other recessive. The recessive will not show up unless the dominant is not present
an allele that will always be expressed if present
an allele that will only be expressed in the absence of the dominant allele
the allele that is being expressed - what is seen
the alleles you possess for a given trait, three types: Homozygous dominant, Homozygous recessive, and heterozygous
Homozygous Recessive
having two recessive alleles for a trait
Homozygous Dominant
having two dominant alleles for a trait
having one dominant and one recessive allele for a trait
Law of Segregation (Mendel's 1st principle)
two alleles of any gene are on homologs that separate from each other in Anaphase of meiosis. Half sex cells get one allele, and the other half get the other
Law of Independent Assortment (Mendel's 2nd principle)
Homolog arrangement in Metaphase I is random, passing a maternal allele from one homolog does not affect any other homologous pair
Sex Linked Traits
A trait that is only present on the 23rd homologous pair- the X or the Y. If a Y linked trait- will always appear since there is only ever one Y in the 23rd homologous pair (Male=xy, Female= xx)
Autosomal Dominant
Trait is dominant: phenotype appears every generation, affected individual has at least one affected parent, affects both male and female
Autosomal Recessive
Trait is recessive: phenotype can skip a generation, affected individual can have unaffected parents, affects both male and female
Complete Dominance
Punnett Square- Dominant trait is ALWAYS dominant
Incomplete Dominance
Phenotype is a blend of dominant and recessive alleles - pink carnation
Phenotype is both alleles, but not blended- more blotchy. Is often ENVIRONMENTALLY influenced
Multiple Alleles
A gene that has more than two possible alleles- you can only inherit two, even if there are more than two possibilities
One gene controls multiple different traits (opposite of polygenic)
Multiple genes control the same trait (opposite of pleiotropic)
Makes up Chromatids- make up chromosomes: Made of histone protines with strands of DNA wrapped around them twice
DNA is a polymer made of ____ monomers
Nucleotides made of: (3 parts)
1. Phosphate group 2. Carbohydrate group (sugar) 3. Nitrogenous base
2 classes of nitrogenous bases
1. Purines 2. Pyramidines
Purines (2)
Adenine and Guanine
Pyramidines (2)
Cytosine and Thymine
"Railing" of DNA made of
Alternating Carbohydrates and phosphates
Carbohydrates in "railing" of DNA is____ bonded to ____
covalently bonded to "rungs" of nitrogenous bases
"Rungs" of DNA made of _____, ______ bonded
two nitrogenous bases, hydrogen-bonded together
Adenine always bonds with _____ (part of Chargoff's Rules)
Thymine always bonds with_____(part of Chargoff's Rules)
Guanine always bonds with _____(part of Chargoff's Rules)
Cytosine always bonds with _____(part of Chargoff's Rules)
Chargoff's Rules say:
which nitrogenous bases will bond together
Order of pairs of nitrogenous bases in DNA
variable- determines an individual's genetic code