5095756
Description
Flashcards by Sydney Franko, updated more than 1 year ago
|
|
Created by Sydney Franko
over 8 years ago
|
|
| Question | Answer |
| Gregor Mendel (1840s) | – Austrian monk – Background as a farmer – Statistician (strong background in mathematics) - counted the different types of offspring – Worked with pea plants Pisum sativum – He was a plant breeder and a mathematician |
| Pea Plants are great genetic model organism | – Inexpensive – Short lifetime – Many observable traits – Lots of progeny – Self-fertilizing – Can be cross-fertilized – Pea plant offspring can be used to describe the heredity patterns of traits (how information is passed from parent to offspring) |
| Genes | – Units of information about specific traits, passed from parent to offspring – Each gene has a specific location (locus) on a chromosome. |
| Locus | The specific location or position of a gene, DNA sequence, on a chromosome |
| Chromosome | – DNA and its associated proteins - involved in the hereditary information of cells |
| Alleles | – Different molecular forms of the same gene – Example: The gene for eye color has 2 alleles. The allele can either contain the gene for blue eye color or the gene for brown eye color. |
| Diploid | - (2n) = pairs of genes on pairs of homologous chromosomes (the chromosomes of the same chromosome type - have the same size and shape) -A cell containing two complete sets of chromosomes, one from each parent. |
| Haploid | – (n) = has half the number of chromosomes (gametes) |
| True-Breeding Lineage | – When offspring of genetic crosses (breeding) that inherit two identical alleles for the same exact trait. All offspring will have the same trait as their parents. – Example: All offspring of a true breeding purple flowered pea plant will have purple flowers. |
| True breeding | Also called a purebred, is an organism that always passes down certain phenotypic traits to its offspring. |
| Hybrid offspring | – When offspring of a genetic cross inherit a pair of non-identical alleles for a trait – Example: Two purple flowered plants produce a white flowering offspring – Aa, aA |
| Homozygous dominant | –Both alleles for the same trait are dominant -AA |
| Homozygous recessive | – Both alleles for the same trait are recessive -Aa |
| Genotype | –The particular genes an organism carries. Show you the pattern of alleles AA (purple flower) Aa (purple flower) aa (white flower) |
| Phenotype | An individual’s observable physical traits (purple flower, white flower) |
| Homozygous | -When both alleles of the pair for a certain trait are identical. -2 of the same alleles |
| Heterozygous | – When the two alleles of a pair for a certain trait are different |
| Terms used for tracking the inheritance of traits through generations of offspring | -P= Parental generation - F1= First generation of offspring (first filial) -F2= Second generation of offspring (second filial) |
| Monohybrid | –Only one trait is followed through a series of genetic crosses. |
| Dihybrid | -Two traits are followed through a series of genetic crosses |
| Mendel's theories | -Theory of segregation -Theory of independent assortment |
| Theory of segregation | During meiosis, the two genes of each pair segregates from each other and end up in different gametes. (alleles separate into different gametes) • Monohybrid cross • Gene segregation |
| Theory of independent assortment | By the end of meiosis, the genes on pairs of homologous chromosomes have sorted independently (into gametes). Deals with different traits |
| Probability | The likelihood that a particular event will happen (flipping a coin) |
| Probability and Punnett squares | –A possibility of outcomes and crosses –Test crosses |
| –What are five factors that can influence patterns of heredity? | -Incomplete Dominance -Codominance -Multiple Alleles -Continuous Variations -Environmental influences |
| Incomplete Dominance | -An individual displays a trait that is intermediate between the 2 parents (snapdragons). -If you have one allele of each you’re going to have a blend of dominant and recessive. (EX. 1 recessive White and 1 dominant red blended heterozygous pink) |
| Codominance | -Two alleles are expressed at the same time (roan coat). -Heterozygous dominant is going to have both alleles showing both colors (ex. Red D and white R the flower will have some of each). |
| Multiple Alleles | -Genes that have traits with more than 2 alleles-blood type has 3 alleles (A,B,O) that determine blood type. -More than just A and a. -When there is a third option of an allele for one genotype. More than one gene interacting to form a trait. |
| Continuous Variation | -Traits for which you see a variety of phenotypes on a continuum from one extreme to another (height, weight). -Many genes and 1 trait. |
| Environmental Influences | -An individual’s phenotype often depends on conditions in the environment. -Example: Many animals such as the arctic fox develop white fur during the cold winter and dark fur in the summer. |
| How blood types are inherited and expressed: | –Type A (AA) –Type AB (AB) –Type B (B i) (BB) –Type O (I I ) |
| Pleiotropy | Effects on two or more traits Ex. Sickle cell anemia |
| Epistasis | -Interactions among products of two or more gene pairs -Two alleles of one gene may mask the expression of another gene’s alleles- so some expected phenotypes may not appear. |
| Hair color in mammals | -Variation in melanin products (Ee, EE, ee) ››allele “E” allows full deposition of melanin -Albinism (total absence of melanin product) |
| Comb shape in poultry | -Interaction between two gene pairs produces a phenotype that neither pair can produce alone |
| Hair color in Labrador Retrievers (epistasis) | -Black (Dominant pigment, dominant 2nd pair) -Yellow (recessive pigment and dominant or recessive 2nd pair) -Brown (dominant pigment and recessive for 2nd pair) |
| Continuous variation | -Eye color -Different amounts of melanin -Different enzymes affect the production |
| Continuous variation (normal distribution) | -Height -The greater number of genes and the environmental factors, the more continuous will be the expected distribution of the trait. |
| -Examples of environmental effects on phenotypes | – Himalayan rabbit – Siamese cat – Heat-sensitive version of enzyme needed for melanin production Warm= white fur Cold= dark fur |
| Hydrangea | -Plants that have the same alleles and have flowers colors raging from pink to blue depending on the acidity of the soil. |
Want to create your own Flashcards for free with GoConqr? Learn more.