Study Guide: Chapter 23 Biology

Define the term allele, and explain what it means for an allele to be dominant or recessive

Allele: alternate forms of a gene for a trait Dominant: capital letter Recessive: Lowercase

Predict outcome ratios and probabilities for problems based on Mendelian patterns of inheritance (monohybrid and dihybrid crosses)

Dihybrid: 9:3:3:1 Monohybrid: 3:1

Contrast genotype and phenotype, and use appropriate terms for describing genotypes

Genotype: the alleles the chromosomes carry that are responsible for that trait Phenotype: refers to the individual's actual appearance Genotypes are dominant or recessive

Explain how the phenotypes for incompletely dominant and codominant traits differ from dominant/recessive trait phenotypes

Incompletely dominant: heterozygote is intermediate between the two homozygous Codominant: when alleles are equally expressed in heterozygote Dominant: The dominant allele is expressed over the recessive gene Recessive: can be masked by dominant

Explain how ABO blood type is an example of multiple allele inheritance

It is an example of multiple allele inheritance because it is a mating between indiciduals with type A blood and type B blood and can result in 4 different blood types, because both parents had type AB blood

Describe how Mendel's Law of segregation and law of independent assortment are related to the movements of chromosomes during gamete formation and fetilization

Law of Independent Assortment: each pair of factors separates independently and all possible combinations of factors can occur in the gametes. Mendel's Law of Segregation: states that allele pairs separate or segregate during gamete formation, and randomly unite at fertilization.

Describe how the environment can influence genetic traits

The environment can influence genetic traits by different things such as temperature. For instance the temperature of stuff can change the color of the fur.

Understand how scientists determine the effect of nature versus nurture

They discovered that behavioral traits are partly inheritable and that genes exert their effects by acting together in complex combinations susceptible to environmental influences

Describe the polygenic inheritance

occurs when a trait is governed by two or more genes