Biology CH 10
Terms
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- True-breeding line(age)
- Constituted similar pure traits over generations
- Inheritance theory 19th century
- "Blending" of fluids from both parents.
- Alleles
-
Alt. forms of a gene
ex: height-> tall, short - Law of segregation
- B4 sexual reproduction occurs, the 2 alleles carried by an individual parent must become segregated,
- Locus
- Designated the location of a specific gene on the chromosome.
- Monohybrid Cross
- Inheritance of 2 different alleles of a single locus (single trait)
- Homozygous
-
Two alleles carried (AA) for this locus are identical.
"true breedin line of ___insert phenotype____. - Heterozygous
- Two alleles carried (Aa) for this locus are different.
- Genotype
- of an organism is described using homozygous and heterozygous.Refers to the genetic constitution or genetic makeup.
- Test cross
- mating between (a) individual that is homozygous recessive and (b)another individual whose genotype is unsure.
- Dihybrid Cross
- Different alleles at two loci. Mating with 2 traits being tracked. Pairs of alleles on NONHOMOLOGOUS chromosomes
- Principle of independent assortment.
- Members of any gene pair segregate from one another independently of the members of the other gene pairs.
- Drosphilia experiment results
- (1) Genes are arranged in a linear order on each chromosome. (2) Independent assrtment doesn't apply is 2 loci lie close together in the same pair of homologous chromosomes.
- Linked genes
- Because locis might happen to be close to each other, they might become linked- they tend to be inheritd together.
- Recombination
- Any process that leads to new gene combinations.
- Crossing over in genetics
- facilitates the recombination of linked genes. The farther apart genes are on a chromosome, the more likely cross-over will occur b/t them.
- Sex-linked genes
- Genes located on the X chromosome,ex: blood clotting & color perception.
- Male: X chromosome
- In males, every allele present on the x chromosome is expressed.
- Hemizygous
- A male has only 1 copy of each X-linked gene.
- Incomplete dominance
- When the heterozygotehas a phenotype intermediate b/t those of its two parents. Genotypic and phenotypic ratios are identical.(red + white=pink)
- Codominance
- Instances in which both traits are expressed (red & white hairs)
- Plieotrophy
- Ability of a single gene to have mulitple effects. (genetic diseases)
- Epistasis
- common type of gene interaction in which the presence of certain alleles of one locus and express its own phenotype instead.
- Polygenic inheritance
- Mulitple independent pairs of genes have similar and additive effects on the same character.
- all
- finished