many genes determine the phenotype; hair color, skin color, etc.
In addition to genotype, ___________ also affects phenotype.
a chart that traces the phenotypes and genotypes within a family
the gene for this type of trait is found on an sex chromosome; mostly males will exhibit this type of trait
what is the genotype of a male human?
neither allele totally masks the expression of the other allele; the offspring's phenotype will be a blend of the parents' phenotypes
both alleles are expressed simultaneously
who could be a carrier for an X-linked trait such as colorblindness?
a person who is heterozygous for a disorder and who does not have the disorder but can pass the disorder to offspring
one of the x chromosomes in each of the cells of female mammals is randomly turned off
type of chromosomes that determine most of the traits expressed in a person's phenotype
men have one X and one Y chromosome--therefore there is no second X chromosome to mask the expression of a trait found on the X chromosome, whereas women have two X chromosomes
why are recessive sex-linked traits more common in men than in women?
a gene that controls the expression of other genes
a picture of all of the chromosomes in a cell, with homologous chromosomes paired and lined up according to size; can show the presence of extra or missing chromosomes, but does not provide information about specific genes
formed when one of the X chromosomes in a female cell is inactivated
type of disorder in which one of the parents must display the trait in order for a child to display the trait
type of disorder that can skip a generation; both parents must carry an allele for the trait
type of disorder in which the mother must be a carrier
these symbols represent individuals that display a particular trait
how many pairs of chromosomes are found in humans?
gametes contain a _________ copy of each chromosome
What is the probability that two parents that are heterozygous for a dominant allele located on an autosome will produce a child that displays the dominant trait?
What is the probability that two parents that are heterozygous for a recessive allele located on an autosome will produce a child that displays the dominant trait?
two recessive alleles
For an XX female to express a recessive sex-linked trait, she must have
What do the letters in a Punnett square represent?
your physical appearance is known as your _____, whereas the actual genes that you have are your _____
yes; Both parents would need to be heterozygous so that the child could inherit the two alleles needed for type O
Is it possible for a couple with blood types A & B to have a child that is type O? Explain
type A, type AB, or type B, depending on whether the type A parent was homozygous or heterozygous
What blood type could a child have if its parents were type AB and type A?
type A or type O (if the type A parent was heterozygous)
What blood type could a child have if its parents were type A and type O?
ABO blood groups
dominant and recessive alleles, codominance, and multiple alleles are all exhibited by what human phenotype?