Biol 105 Genetics with 100%
correct answers (graded A+)
monohybrids - answer Individuals with two different alleles for a single trait
Crossfertilization - answer pollen transferred, dusted onto stigma of
recipient
dominant - answer Trait that appears in F1 progeny
recessive - answer Trait that is hidden in the F1 progeny
Genes - answer Units of inheritance
alleles - answer Alternative forms of a single gene
Mendel's Law of Segregation - answer The two alleles for each trait (i.e.
gene) separate (segregate) during
gamete formation, then unite at
random, one from each parent, at
fertilization
•Occurs as a result of segregation of homologous chromosomes in
Anaphase I of meiosis
•Each gamete only gets one homolog of each pair and therefore only one
allele of each gene
,Phenotype - answer an observable characteristic of an individual (e.g.
yellow or green pea seeds)
Genotype - answer the pair of alleles for a gene (or for each of several
genes) in an individual (e.g. YY or Yy)Ge
Homozygous - answer having two identical alleles for a gene (e.g. YY or
yy.) Homozygous individual is a homozygote
Heterozygous - answer having two different alleles for a gene (e.g. Yy)
Heterozygous individual is a heterozygote.
The Law of Independent Assortment - answer During gamete formation,
alleles of different genes segregate
independently of each other
• Results from the fact that different homologous pairs of chromosomes can
line up in different orientations on the metaphase plate in meiosis I
Multihybrid Crosses - answer To calculate the possible number of gamete
genotypes
from a hybrid, raise 2 to the power of the number of
different traits
Polygenic - answer Many traits are determined by several genes; these traits
don't show simple Mendelian inheritance patterns
monogenic - answer each determined by a single gene
Sbe1 - answer Pea-shape Gene Encodes
,Starch-branching Enzyme 1
Alleles:
R: Functional enzyme
(round)
r: No enzyme
Sgr - answer Pea Color Gene Encodes
"Stay Green" Enzyme
Alleles:
Y: Functional enzyme (yellow)
y: No enzyme
CFTR - answer Gene Encodes a Chloride Channel Protein
When Mutated Causes Cystic Fibrosis
Sickle-cell anemia
(chromosome 11) - answer recessive
Abnormal hemoglobin; sickleshaped
red cells, anemia, blocked
circulation; increased resistance
to malaria
1/625 AfricanAmericans
Cystic fibrosis
(chromosome 7) - answer recessive
Defective cell membrane protein;
excessive mucus production;
digestive and respiratory failure
, 1/2000 caucasians
Tay-Sachs disease
(chromosome 15) - answer recessive
Missing enzyme; buildup of fatty
deposit in brain; buildup disrupts
mental development
1/3000 Eastern
European Jews
Huntington disease
(chromosome 4) - answer dominant
Progressive mental and
neurological damage; neurologic
disorders by ages 40 - 70
1/25,000 Caucasians
Rare
Dominant Trait - answer • Every affected
person has at
least one
affected parent
• Mating between
affected person
and unaffected
person is
effectively a
testcross
correct answers (graded A+)
monohybrids - answer Individuals with two different alleles for a single trait
Crossfertilization - answer pollen transferred, dusted onto stigma of
recipient
dominant - answer Trait that appears in F1 progeny
recessive - answer Trait that is hidden in the F1 progeny
Genes - answer Units of inheritance
alleles - answer Alternative forms of a single gene
Mendel's Law of Segregation - answer The two alleles for each trait (i.e.
gene) separate (segregate) during
gamete formation, then unite at
random, one from each parent, at
fertilization
•Occurs as a result of segregation of homologous chromosomes in
Anaphase I of meiosis
•Each gamete only gets one homolog of each pair and therefore only one
allele of each gene
,Phenotype - answer an observable characteristic of an individual (e.g.
yellow or green pea seeds)
Genotype - answer the pair of alleles for a gene (or for each of several
genes) in an individual (e.g. YY or Yy)Ge
Homozygous - answer having two identical alleles for a gene (e.g. YY or
yy.) Homozygous individual is a homozygote
Heterozygous - answer having two different alleles for a gene (e.g. Yy)
Heterozygous individual is a heterozygote.
The Law of Independent Assortment - answer During gamete formation,
alleles of different genes segregate
independently of each other
• Results from the fact that different homologous pairs of chromosomes can
line up in different orientations on the metaphase plate in meiosis I
Multihybrid Crosses - answer To calculate the possible number of gamete
genotypes
from a hybrid, raise 2 to the power of the number of
different traits
Polygenic - answer Many traits are determined by several genes; these traits
don't show simple Mendelian inheritance patterns
monogenic - answer each determined by a single gene
Sbe1 - answer Pea-shape Gene Encodes
,Starch-branching Enzyme 1
Alleles:
R: Functional enzyme
(round)
r: No enzyme
Sgr - answer Pea Color Gene Encodes
"Stay Green" Enzyme
Alleles:
Y: Functional enzyme (yellow)
y: No enzyme
CFTR - answer Gene Encodes a Chloride Channel Protein
When Mutated Causes Cystic Fibrosis
Sickle-cell anemia
(chromosome 11) - answer recessive
Abnormal hemoglobin; sickleshaped
red cells, anemia, blocked
circulation; increased resistance
to malaria
1/625 AfricanAmericans
Cystic fibrosis
(chromosome 7) - answer recessive
Defective cell membrane protein;
excessive mucus production;
digestive and respiratory failure
, 1/2000 caucasians
Tay-Sachs disease
(chromosome 15) - answer recessive
Missing enzyme; buildup of fatty
deposit in brain; buildup disrupts
mental development
1/3000 Eastern
European Jews
Huntington disease
(chromosome 4) - answer dominant
Progressive mental and
neurological damage; neurologic
disorders by ages 40 - 70
1/25,000 Caucasians
Rare
Dominant Trait - answer • Every affected
person has at
least one
affected parent
• Mating between
affected person
and unaffected
person is
effectively a
testcross
