Bio 121 Exam 2 Questions With All Correct
Answers
What are the three hypothesis of inheritance Correct answer-1. There are alternative forms of
"factors"(allels)
2. For each inherited trait, there are 2 allels from each parent
3. Sperm and egg only carrie one allel
4. When 2 allels are different in a pair, one is expressed
Principal of segregation Correct answer-When two allels in a pair are different, 1 is fully expressed
while the other is masked
Locus Correct answer-Location on a chromosome
Homozygous Correct answer-Pair of the same allels (RR) or (rr)
Heterozygous Correct answer-Pair of two different allels (Rr)
Phenotype Correct answer-Physical expressed traits
Genotype Correct answer-Actual genetic makeup of an organism
What do you do if there are 4 allels that segregate independently Correct answer-Dihybrid cross
Probability Correct answer-Outcome of that event/ total # of possible outcomes
Incomplete dominance Correct answer-F1 hybrids are intermediate between parental genotype
(pink flowers)
Complementation Correct answer-One of the two pairs of allels needs to be homozygous dominant
to express phenotype
Epistasis Correct answer-One allel pair masks the effect of the other pair (lab dogs)
Modifier gene Correct answer-Controlled by 1 locus
Polygenics of quantitative traits Correct answer-Controlled by 5-10 loca,(height/skin/hair color)
Pleitrophy Correct answer-Single gene has multiple phenotypic effects characteristics (deafness in
white cats)
Penetrance Correct answer-% of individuals carrying a gene and expressing phenotype
Expressivity Correct answer-Degree to which a gene is expressed(mild or severe)
Epigenetics Correct answer-When experiences change the way DNA is expressed, can be passed to
offspring.
Concordance rates Correct answer-Probability that a pair of individuals both have a certain trait
, Autosomal recessive Correct answer-Harmful gene Inherited by having both carrier parents
Autosomal dominance Correct answer-Harmful dominant allel typically late onset, expressed later
in life.
Sex linked Correct answer-Locus is on X and Y chromosomes, will affect males more than females
What neucleotides are in DNA Correct answer-Adenine-thymine(uracil)
Granine(cytosine)
Transcription Correct answer-When mRNA records the DNA template.
Translation Correct answer-The decoding of mRNA into polypeptides
Codons Correct answer-Groups of 3 neucleotides that are translated into by polypeptide chain
Start codon Correct answer-AUG
Stop codons Correct answer-UUA,UAG, and UGA
Mutation Correct answer-Heritable change in genes
Point mutation: silent Correct answer-No change in protein sequence
Point mutation: missense Correct answer-Results in amino acid substitution
Point mutation: nonsense Correct answer-Stop codon is substituted
Frame shift mutation Correct answer-One added or forgotten neucleotide, shifts all codon over
creating the incorrect proteins.Disasterous
Spontaneous mutation Correct answer-Errors during replication
Mutagens Correct answer-Substances chemical/physical causing mutations
Transposable elements (mutations) Correct answer-Mobile segments of DNA insert and disrupt
genes
If genes are always copied perfectly Correct answer-No evolution
Lamark Correct answer-1. use and disuse of parts, organisms are directed towards perfection so
they adapt to used and disused parts
2. Inheritance of acquired characteristics (false)
Darwin's findings Correct answer-Individuals with inheritable variations that are favorable will
survive in greater numbers and produce more offspring
An all powerful genotype... Correct answer--does not exist.
Gene pool Correct answer-total amount of genes of all individuals in a population
Answers
What are the three hypothesis of inheritance Correct answer-1. There are alternative forms of
"factors"(allels)
2. For each inherited trait, there are 2 allels from each parent
3. Sperm and egg only carrie one allel
4. When 2 allels are different in a pair, one is expressed
Principal of segregation Correct answer-When two allels in a pair are different, 1 is fully expressed
while the other is masked
Locus Correct answer-Location on a chromosome
Homozygous Correct answer-Pair of the same allels (RR) or (rr)
Heterozygous Correct answer-Pair of two different allels (Rr)
Phenotype Correct answer-Physical expressed traits
Genotype Correct answer-Actual genetic makeup of an organism
What do you do if there are 4 allels that segregate independently Correct answer-Dihybrid cross
Probability Correct answer-Outcome of that event/ total # of possible outcomes
Incomplete dominance Correct answer-F1 hybrids are intermediate between parental genotype
(pink flowers)
Complementation Correct answer-One of the two pairs of allels needs to be homozygous dominant
to express phenotype
Epistasis Correct answer-One allel pair masks the effect of the other pair (lab dogs)
Modifier gene Correct answer-Controlled by 1 locus
Polygenics of quantitative traits Correct answer-Controlled by 5-10 loca,(height/skin/hair color)
Pleitrophy Correct answer-Single gene has multiple phenotypic effects characteristics (deafness in
white cats)
Penetrance Correct answer-% of individuals carrying a gene and expressing phenotype
Expressivity Correct answer-Degree to which a gene is expressed(mild or severe)
Epigenetics Correct answer-When experiences change the way DNA is expressed, can be passed to
offspring.
Concordance rates Correct answer-Probability that a pair of individuals both have a certain trait
, Autosomal recessive Correct answer-Harmful gene Inherited by having both carrier parents
Autosomal dominance Correct answer-Harmful dominant allel typically late onset, expressed later
in life.
Sex linked Correct answer-Locus is on X and Y chromosomes, will affect males more than females
What neucleotides are in DNA Correct answer-Adenine-thymine(uracil)
Granine(cytosine)
Transcription Correct answer-When mRNA records the DNA template.
Translation Correct answer-The decoding of mRNA into polypeptides
Codons Correct answer-Groups of 3 neucleotides that are translated into by polypeptide chain
Start codon Correct answer-AUG
Stop codons Correct answer-UUA,UAG, and UGA
Mutation Correct answer-Heritable change in genes
Point mutation: silent Correct answer-No change in protein sequence
Point mutation: missense Correct answer-Results in amino acid substitution
Point mutation: nonsense Correct answer-Stop codon is substituted
Frame shift mutation Correct answer-One added or forgotten neucleotide, shifts all codon over
creating the incorrect proteins.Disasterous
Spontaneous mutation Correct answer-Errors during replication
Mutagens Correct answer-Substances chemical/physical causing mutations
Transposable elements (mutations) Correct answer-Mobile segments of DNA insert and disrupt
genes
If genes are always copied perfectly Correct answer-No evolution
Lamark Correct answer-1. use and disuse of parts, organisms are directed towards perfection so
they adapt to used and disused parts
2. Inheritance of acquired characteristics (false)
Darwin's findings Correct answer-Individuals with inheritable variations that are favorable will
survive in greater numbers and produce more offspring
An all powerful genotype... Correct answer--does not exist.
Gene pool Correct answer-total amount of genes of all individuals in a population
