Genetics & Heredity Flashcards
Where are the genes for most sex-linked traits located?
On the “X” chromosome.
A red flower and a white flower are crossed and produce all pink offspring. This is an example of ______________________.
Incomplete dominance.
Why are human blood types considered an example of codominance?
The blood types A and B will both be expressed when present.
How many pairs of homologous chromosomes do humans have?
23
If two different alleles are present, which allele is expressed?
The dominant allele.
A tall pea plant (DD) and a tall pea plant (Dd) have what in common?
They are the same phenotype.
In a pedigree chart a recessive trait is seen mostly in males, what does this tell you about the mode of inheritance?
It is a sex-linked trait.
If a trait is seen in many organisms of a species population, then you may assume that trait is ____________.
Dominant
If a trait is seen in few organisms of a species population, then you may assume that trait is ____________.
Recessive
The gender of an animal is determined by the _______ chromosome.
Y
An individual with one dominant allele and one recessive allele (Aa) is said to be ________________.
Heterozygous
An individual with two dominant alleles (AA) is said to be _________________________.
Homozygous dominant
An individual with two recessive alleles (aa) is said to be _________________________.
Homozygous recessive
In what phase of meiosis does crossing over occur?
Prophase 1
If a plant has 52 chromosomes, then there will be ______ chromosomes in the gametes?
26 (half the number of the diploid cell)
What blood type is considered the universal donor?
O
The physical appearance of an organisms alleles is called the ____________.
Phenotype
The genetic composition of an organism is called the _____________.
Genotype
The study of heredity and traits is ___________.
Genetics.
An inherited characteristic is a ___________.
Trait
The passing of traits from parent to offspring is _____________,
Heredity
If two heterozygous organisms are crossed what are the genotypic and phenotypic ratios?
Genotypic = 1:2:1 Phenotypic = 3:1
If brown hair is dominant (B) to blonde hair (b), then what color hair would an individual with a Bb genotype have?
Brown
If brown hair is dominant (B) to blonde hair (b), then what color hair would an individual with a BB genotype have?
Brown
If brown hair is dominant (B) to blonde hair (b), then what color hair would an individual with a bb genotype have?
Blonde
