Bio chapter 9
Terms in this set (43)
The transmission of traits from one generation to the next.
The scientific study of heredity.
A heritable feature that varies among individuals
A characteristic that an organism can pass on to its offspring through its genes.
Referring to organisms for which sexual reproduction produces offspring with inherited traits identical to those of the parents. The organisms are homozygous for the characteristics under consideration.
The parent individuals from which offspring are derived in studies of inheritance; P stands for parental.
The offspring of two parental (P generation) individuals; F1 stands for first filial.
The offspring of the F1 generation; F2 stands for second filial.
An organism that has two different alleles for a trait; an organism that is heterozygous for a particular trait.
A process occurring during meiosis wherein two chromosomes pair up and exchange segments of their genetic material.
An experimental mating of individuals differing in a single character.
Alternative versions of a gene
Having two identical alleles for a particular gene
Having two different alleles for a given gene.
The allele that determines the phenotype of a gene when the individual is heterozygous for that gene.
An allele that has no noticeable effect on the phenotype of a gene when the individual is heterozygous for that gene.
Law of segregation
A general rule in inheritance (originally formulated by Gregor Mendel) that individuals have two alleles for each gene and that when gametes form by meiosis, the two alleles separate, each resulting gamete ending up with only one allele of each gene; also known as Mendel's first law of inheritance.
A diagram for predicting the allele composition of offspring from a cross between individuals of known genetic makeup.
An organism's physical appearance, or visible traits.
An organism's genetic makeup
A cross between two organisms that are each heterozygous for both of the characters being followed (or the self-pollination of a plant that is heterozygous for both characters).
Law of independent assortment
A general rule in inheritance (originally formulated by Gregor Mendel) that when gametes form during meiosis, each pair of alleles for a particular characteristic segregate independently of other pairs; also known as Mendel's second law of inheritance.
a cross between an organism whose genotype for a certain trait is unknown and an organism that is homozygous recessive for that trait so the unknown genotype can be determined from that of the offspring
Rule of multiplication
A rule stating that the probability of a compound event is the product of the separate probabilities of the independent events.
Rule of addition
A rule stating that the probability that an event can occur in two or more alternative ways is the sum of the separate probabilities of the different ways.
The version of a character that most commonly occurs in nature.
a neurological disorder characterized by various motor symptoms affecting 1 in 10,000 in the US. Associated with gradual and extensive brain damage in the caudate nucleus, putamen, globus pallidus, and cerebral cortex
An individual who is heterozygous for a recessively inherited disorder and who therefore does not show symptoms of that disorder but who may pass on the recessive allele to offspring.
A technique of prenatal diagnosis in which amniotic fluid, obtained by aspiration from a needle inserted into the uterus, is analyzed to detect certain genetic and congenital defects in the fetus.
Chorionic villus sampling
A technique for diagnosing genetic defects while the fetus is in an early development stage within the uterus. A small sample of the fetal portion of the placenta is removed and analyzed.
A technique for examining a fetus in the uterus. High-frequency sound waves echoing off the fetus are used to produce an image of the fetus.
A type of inheritance in which the phenotypes of the heterozygote and dominant homozygote are indistinguishable.
A type of inheritance in which two contrasting alleles contribute to the individual a trait not exactly like either parent; blending inheritance.
ABO blood group
Genetically determined classes of human blood that are based on the presence or absence of carbohydrates A and B on the surface of red blood cells. The ABO blood group phenotypes, also called blood types, are A, B, AB, and O.
Inheritance pattern in which a heterozygote expresses the distinct trait of both alleles.
The control of more than one phenotypic characteristic by a single gene.
Genetic disorder in which red blood cells have abnormal hemoglobin molecules and take on an abnormal shape.
The addictive effects of the two or more gene loci on a single phenotypic character.
Chromosome theory of inheritance
A basic principle in biology stating that genes are located on chromosomes and that the behavior of chromosomes during meiosis accounts for inheritance patterns.
Genes located close enough together on a chromosome that they tend to be inherited together.
With respect to two given genes, the number of recombinant progeny from a mating divided by the total number of progeny. Recombinant progeny carry combinations of alleles different from those in either of the parents as a result of crossing over during meiosis.
A chromosome that determines whether an individual is male or female.
A gene located on a sex chromosome. In humans, the vast majority of sex-linked genes are located on the X chromosome.