AP®︎ Biology: Topic 5.4 Practice Test
Prepare for your quiz, test, or the AP exam with focused practice questions on Topic 5.4 of AP Biology – Non-Mendelian Genetics.
Questions List
Topic 5.4
Question 1 Easy
This question tests the following: IST-1.J.3
Which term describes a situation where a trait is determined by more than two alleles?
What You’re Being Tested On:
Explore the learning objectives taken directly from the College Board’s AP® Biology Curriculum. Ensure you’re prepared for the exact topics covered on the AP® exam, in-class tests, and quizzes, and gain confidence in your mastery of the material.
Topic 5.4: Non-Mendelian Genetics
Learning Objective: 5.4.A
Explain deviations from Mendel’s model of the inheritance of traits.
Essential Knowledge: 5.4.A.1
Patterns of inheritance of many traits do not follow the ratios predicted by Mendel’s laws and can be identified by quantitative analysis, when the observed phenotypic ratios statistically differ from the predicted ratios. i. Genes located on the same chromosome are referred to as being genetically linked. The probability that these linked genes segregate together during meiosis can be used to calculate the map distance (or map units) between them on a chromosome. This calculation is called gene or genetic mapping. ii. Codominance occurs when the phenotype from both alleles is expressed such that the heterozygote would have a different phenotype than either homozygote. iii. Incomplete dominance occurs when neither allele of a gene can mask the other, so the phenotype of the heterozygote is a blended version of the dominant and recessive phenotypes.
Essential Knowledge: 5.4.A.2
Some traits, known as sex-linked traits (X- or Y-linked), are determined by genes on sex chromosomes. The pattern of inheritance of sex-linked traits can often be predicted from data, including pedigrees, indicating the genotypes and phenotypes of both parents and offspring. Illustrative examples: Sex-linked traits (X- or Y-linked) reside on sex chromosomes.; Sex-linked traits (X- or Y-linked) are inherited at higher rates in XY individuals than they are in XX individuals.; In certain species, the chromosomal basis of sex determination is not based on X and Y chromosomes (e.g., ZW in birds, haplodiploidy in bees).
Essential Knowledge: 5.4.A.3
Pleiotropy is a phenomenon in which the expression of a single gene results in multiple traits or effects; these traits therefore do not segregate independently.
Essential Knowledge: 5.4.A.4
Some traits result from non-nuclear inheritance. i. Chloroplasts and mitochondria are randomly assorted to gametes and daughter cells; thus, traits determined by chloroplast and mitochondrial DNA do not follow simple Mendelian rules. ii. In animals, mitochondria are usually transmitted by the egg and not by sperm; thus, traits determined by the mitochondrial DNA are typically maternally inherited. iii. In plants, mitochondria and chloroplasts are transmitted in the ovule and not in the pollen; as such, mitochondria-determined and chloroplast-determined traits are typically maternally inherited.
