Genetics Flashcards
A unit that determines heritable characteristics
Gene
Organisms that always produce offspring identical to parents
True- breeding
The offspring of two different varieties
Hybrid
When two different alleles of a pair are different, the one is masked
Recessive
An incorrect idea that acquired characteristics are passed on
Pangenesis
Parent organisms that are mated
P generation
A diagram that shows possible combinations of gametes
Punnett square
A breeding experiment that uses parents different in one characteristic
Monohybrid cross
One of the alternative forms of a gene for a characteristic
Allele
Relative numbers of organisms with various characteristics
Phenotypic ratio
An organism that has two different alleles for a characteristic
Heterozygous
Old idea that heredity materials from parents mix into offspring
Blending
An organisms genetic make up
Genotype
Separation of allele pairs that occurs during gamete formation
Segregation
Fertilization of a plant by pollen from a different plant
Cross- Fertilization
An organism that has two identical alleles for a characteristic
Homozygous
Offspring of the P generation
F1 generation
A characteristic most commonly found in nature
Wild type
What an organism looks like; its expressed traits
Phenotype
Offspring of the F1 generation
F2 generation
When pollen fertilizes eggs from the same flower
Self fertilization
A hybridization
Cross
When two alleles of a pair are different, the one expressed
Dominant
Where genes for a certain trait are located
Homologous chromosomes
Offspring is an ___ event
independent
freckles are
dominant
widows peak is
dominant
Free earlobes are
dominant
sickle cell
half moon shape. hemoglobin cant attach and cant carry oxygen
how many pairs of chromosomes
23
1-22
autosomal (characteristics of body)
23
sex/gender
Cystic fibrosis is the most common lethal genetic disease in the united states
true
A genetic disorder is expected in half the children of two carries of a recessive allele
false: 1/4
About 50 human genetic disorders are known to be inherited as Mendelian traits
true
Most people afflicted with genetic disorders are born to afflicted parents
false: not born
Most serious human genetic disorders are recessive
true
Cystic fibrosis is most common among Asian Americans
false; caucasians
Most genetic disease are evenly distributed evenly among ethnic groups
false; not evenly
Most societies have taboos and laws against marriage between close relatives
true
half of the offspring of two carriers of a recessive allele are likely to be carriers
true
dominant alleles are always more common in the population than recessive alleles
not always
Tay- sachs disease is seen among Jews from central Europe
true
Lethal dominant alleles are much more common than lethal recessive alleles
less
Achondroplasia is a form of dwarfism
true
Geneticists agree that inbreeding always increases the risk of inherited diseases
false; debate
Huntingtons disease is lethal, but it does not strike until middle age
true
Symptoms of PKU include excess mucus in the lungs and digestive tract
false; cystic fibrosis
Extra fingers and toes is a dominant trait
true
sickle cell disease is common among African Americans
true
Karyotype
Take a picture of chromosomes
Down syndrome
Taking a sample of amniotic fluid
Amniocentesis
New technique that gets results back faster
Chorionicvillus
