Chapter 4 Flashcards
Mendelian traits
Characteristics that are influenced by alleles at one genetic locus. (Sickle cell anemia and Ray Sachs Are correlated to these traits)
Allele frequency
In a population, the percentage of the alleles at a locus accounted for by one specific allele
Antigens
Large molecules found on the surface of cells. Several different loci govern various antigens on red and white blood cells
Micro evolution
Small changes occurring within species such as changes in allele frequencies
Codominance
The expression of two alleles I heterozygotes. In this situation neither allele is dominant or recessive, so they both influence the phenotype.
Pedigree chart
A diagram hoeing family relationships. It’s used to trace the hereditary pattern of particular genetic (usually Mendelian) traits
Pigment
Molecules that influence the color of skin hair and eyes
Dominant
A trait governed by an allele that’s express in the prescience of another allele. Prevent the expression of recessive alleles in heterozygotes
Phenotype
The observable physical characteristics of an organism, frequently influenced by environmental factors
Pleiotropy
A situation where the action of one gene affects several different traits
Founder effect
A type of genetic drift in which allele frequencies are altered in small population that are taken from larger populations or are remnants of the latter
Point mutation
A type of mutation that causes the replacement of a single base nucleotide with another nucleotide of the genetic material, DNA or RNA.
Gene flow
Exchange of genes between populations
Polygenic
Referring to traits influenced by genes at two or more loci. Ex. Are stature, skin color, eye color, and hair color. Often influenced by environmental factors such as nutrition and exposure to sunlight
Gene pool
All of the genes shared by the reproductive members of a population
Population
Within a species a community of individuals where mates are usually found
Genetic drift
Evolutionary changes or changes in allele frequencies produced by random favored in small populations. Is a result of small population size.
Principle of independent assortment
The distribution of one pair of alleles into gametes does not influence the distribution of another pair l. The genes controlling different traits are inherited independently of one another
Genotype
The genetic makeup of an individual. Refers Ronan organisms genetic makeup at a particular locus
Genotype
The genetic makeup
Of a cell, an organism/individual usually with reference to a specific characteristic under consideration
Principle of segregation
Genes occur in pairs because chromosomes occur in pairs. During gamete formation, the members of each pair of alleles separate so that each gamete contains one member of each pair
Heterozygous
Having different alleles at the same locus on members of a pair of chromosomes
Macro evolution
Changes produced only after many generation such as the appearance of new species
Tandem repeats
Shirt adjacent segments of DNA within a gene that are repeated several times
Variation
In genetics inherited differences among individuals, the basis of all evolutionary change.
Hybrids
Offspring of parents who differ from eachother with regard to certain traits of certain aspects of genetic makeup, also known as heterozygotes
