Genetics Flashcards
He coined the central dogma of molecular biology.
Francis Crick
Molecular basis of heredity; the study of genes, genetic variation, and heredity in organisms; seeks to account for the resemblances and differences due to heredity and their development
Genetics
An Australian monk whose experiments on garden peas (1866) lead to laying down of basic genetic principles
Gregor Johann Mendel
Basic unit of heredity; found in chromosomes; the factors for the character; the unit of inheritance that is transmitted in a gamete and controls the development of a character; highly coiled DNA
Gene
Pair of genes that controls an observable trait; factors responsible for a pair of alternative or contrasted character; one member of a pair or series of genes that occupy a specific position on a specific chromosome; variant form of a gene
Allele(s)
Number of alleles humans have at a genetic locus
Two
Inheriting from parents; passing on; deals with characteristics
Heredity
Two types of variations:
- Environmental
- Hereditary
Two types of alleles:
- Heterozygous
- Homozygous
Hybrid; having two different alleles of a particular gene or genes
Heterozygous
Pure breed; having two identical alleles of a particular gene or genes
Homozygous
Involved with appearance; observable or external trait of an organism
Phenotype
Genetic composition; entire genetic constituent of an individual; kinds of genes an organism possesses
Genotype
Asserted that the original parental traits were lost or absorbed by the blending in the offspring
Blending theory of inheritance
Results from the action of many genes to determine a characteristic like human height; offspring appear to be a “blend” of their parents’ traits
Continuous variation
Mendel worked with traits that were inherited in distinct classes referred to as ___
Discontinuous variation
Involve mating two true-breeding individuals that have different traits
Hybridization
The parental generation
P0
The first filial (offspring) generation
F1
The second filial generation
F2
Defined as a variation in the physical appearance of a heritable characteristic
Trait
A paired cross in which the respective traits of the male and female in one cross become the respective traits of the female and male in the other cross
Reciprocal cross
Traits that are inherited unchanged in a hybridization; expressed or evident
Dominant traits
Traits that become latent, or disappear, in the offspring of a hybridization; may reappear in the progeny of the hybrid offspring
Recessive traits
A rule that states that the probability of two independent events occuring together can be calculated by multiplying the individual probabilities of each event occurring alone
Product rule of probability
A rule that states that the probability of the occurrence of one event or the other event, of two mutually exclusive events, is the sum of their individual probabilities.
Sum rule of probability
The process when fertilization occurs between two true-breeding parents that differ in only one characteristic; the resulting offspring are monohybrids; parents differ only with one pair of alternative trait/characteristic
Monohybrid cross
Devised by Reginald Punnett; can be drawn that applies the rules of probability to predict the possible outcomes of a genetic cross or mating and their expected frequencies
Punnett square
States that when 2 contrasting characters are brought together in a cross, one is dominant in the next generation (F1) and the other is recessive
Principle of dominance
Two laws according to Mendel:
- Law of segregation: First Law
- Law of independent assortment: Second Law
A pattern of inheritance, denoting the expression of two contrasting alleles such that the individual displays an intermediate phenotype; genes not always dominant or recessive
Incomplete dominance
A variation on incomplete dominance, in which both alleles for the same characteristic are simultaneously expressed in the heterozygote
Codominance
Non-sex chromosomes
Autosomes
Characteristic of male because they have only one allele for any X-linked characteristic
Hemizygous