BIO 100 Exam 3 - Questions and Answers The term ______ refers to the outward expression of a trait, either physically, microscopically, or
... [Show More] metabolically. Phenotype The phenotype of an organizsm is determined by which ______ their chromosomes possess for a specific trait. Alleles This set of alleles is referred to as the organizsm's ______. Genotype Genes are located on ______ each chromosome contains one allele for each gene at a site called the gene's ______. chromosomes, locus For diploid organisms, each cell contains ______ alleles for each trait, one allele on a chromosome from the mother and the other on a chromosome from the father. Two Chromosomes carry genes from parent to offspring and are distributed to gametes during ______ each gamete receives one copy of each chromosome and therefore one allele for each ______. meiosis, gene When viewing a dominant phenotype, the ______ can be unknown. Genotype A dominant phenotype can be either homozygous dominant or ______. Heterozygous A _________ can determine the genotype of a dominant phenotype. Testcross By mating the unknown dominant organism with a homozygous ____________ organism, the genotype can be determined from the offspring. Recessive If the unknown organism is homozygous dominant, all offspring will be ________. Dominant If the unknown is a heterozygote, there can be phenotypically ________ individuals in the offspring. Recessive Parents transmit information about traits to their offspring in units called ____. Genes A diploid individual contains two alternative forms, or ______, for each gene. Alleles IF the two alleles are the same, the individual is said to be ________, if the two alleles are different, the individual is said to be __________. Homozygous, heterozygous The particular alleles that an individual has are the individual's ______, whereas the appearance of an individual is called it's _________. Genotype, phenotype Mendel observed the alleles can be dominant or ______, and the ______ allele typically masks the expression of the other allele. Recessive, dominant When a single trait is affected by more than one gene locus, this is called _________________. Polygenic inheritance. When a single gene locus affects more than one trait, this is called _____. Pleiotropy When a single gene locus has more than two possible alleles, this is called _________. Multiple alleles. When the phenotype of heterozygotes is intermediate between the homozygotes, this is called __________. Incomplete dominance When the phenotype of heterozygotes shows some aspects of both homozygotes, this is called _________. Co-dominance When alleles at one gene locus can interfere with the expression of alleles at another gene locus, this is called _______. Epistasis In some pairs of alleles, ______dominance is exhibited when the heterozygote has an intermediate phenotype. incomplete [Show Less]