Essentials of Physical Anthropology -
Exam 1 Review
allele frequency - correct answer ✔✔In a population, the percentage of all the alleles at a locus
accounted for by one specific allele.
alleles - correct answer ✔✔Alternate forms of a gene. ______ occur at the same locus on both members
of a pair of chromosomes, and they influence the same trait. But because they're slightly different from
one another, their action may result in different expressions of that trait. The term is sometimes used
synonymously with gene.
antigens - correct answer ✔✔Large molecules found on the surface of cells. Several different loci govern
various ______on red and white blood cells. (Foreign ______ provoke an immune response.)
codominance - correct answer ✔✔The expression of two alleles in heterozygotes. In this situation,
neither allele is dominant or recessive, so they both influence the phenotype.
dominant - correct answer ✔✔In genetics, describing a trait governed by an allele that's expressed in the
presence of another allele (that is, in heterozygotes). ________ alleles prevent the expression of
recessive alleles in heterozygotes. (This is the definition of complete ________.)
founder effect - correct answer ✔✔A type of genetic drift in which allele frequencies are altered in small
populations that are taken from, or are remnants of, larger populations.
gene flow - correct answer ✔✔Exchange of genes between populations.
gene pool - correct answer ✔✔All of the genes shared by the reproductive members of a population.
genetic drift - correct answer ✔✔Evolutionary changes, or changes in allele frequencies, that are
produced by random factors in small populations. ___________ is a result of small population size.
, genotype - correct answer ✔✔The genetic makeup of an individual. This can refer to an organism's
entire genetic makeup or to the alleles at a particular locus.
heterozygous - correct answer ✔✔Having different alleles at the same locus on members of a pair of
chromosomes.
homozygous - correct answer ✔✔Having the same allele at the same locus on both members of a pair of
chromosomes.
hybrids - correct answer ✔✔Offspring of parents who differ from each other with regard to certain traits
or certain aspects of genetic makeup; heterozygotes.
locus (pl., loci) - correct answer ✔✔The position on a chromosome where a given gene occurs. The term
is frequently used interchangeably with gene.
macroevolution - correct answer ✔✔Changes produced only after many generations, such as the
appearance of a new species.
Mendelian traits - correct answer ✔✔Characteristics that are influenced by alleles at only one genetic
locus. Examples include many blood types, such as ABO. Many genetic disorders, including sickle-cell
anemia and Tay-Sachs disease, are also ________________.
microevolution - correct answer ✔✔Small changes occurring within species, such as changes in allele
frequencies.
phenotypes - correct answer ✔✔The observable or detectable physical characteristics of an organism;
the detectable expressions of genotypes, frequently influenced by environmental factors.
pigment - correct answer ✔✔In this context, a molecule that influences the color of skin, hair, and eyes.
polygenic - correct answer ✔✔Referring to traits that are influenced by genes at two or more loci.
Examples include stature, skin color, eye color, and hair color. Many (but not all) __________ traits are
influenced by environmental factors such as nutrition and exposure to sunlight.
Exam 1 Review
allele frequency - correct answer ✔✔In a population, the percentage of all the alleles at a locus
accounted for by one specific allele.
alleles - correct answer ✔✔Alternate forms of a gene. ______ occur at the same locus on both members
of a pair of chromosomes, and they influence the same trait. But because they're slightly different from
one another, their action may result in different expressions of that trait. The term is sometimes used
synonymously with gene.
antigens - correct answer ✔✔Large molecules found on the surface of cells. Several different loci govern
various ______on red and white blood cells. (Foreign ______ provoke an immune response.)
codominance - correct answer ✔✔The expression of two alleles in heterozygotes. In this situation,
neither allele is dominant or recessive, so they both influence the phenotype.
dominant - correct answer ✔✔In genetics, describing a trait governed by an allele that's expressed in the
presence of another allele (that is, in heterozygotes). ________ alleles prevent the expression of
recessive alleles in heterozygotes. (This is the definition of complete ________.)
founder effect - correct answer ✔✔A type of genetic drift in which allele frequencies are altered in small
populations that are taken from, or are remnants of, larger populations.
gene flow - correct answer ✔✔Exchange of genes between populations.
gene pool - correct answer ✔✔All of the genes shared by the reproductive members of a population.
genetic drift - correct answer ✔✔Evolutionary changes, or changes in allele frequencies, that are
produced by random factors in small populations. ___________ is a result of small population size.
, genotype - correct answer ✔✔The genetic makeup of an individual. This can refer to an organism's
entire genetic makeup or to the alleles at a particular locus.
heterozygous - correct answer ✔✔Having different alleles at the same locus on members of a pair of
chromosomes.
homozygous - correct answer ✔✔Having the same allele at the same locus on both members of a pair of
chromosomes.
hybrids - correct answer ✔✔Offspring of parents who differ from each other with regard to certain traits
or certain aspects of genetic makeup; heterozygotes.
locus (pl., loci) - correct answer ✔✔The position on a chromosome where a given gene occurs. The term
is frequently used interchangeably with gene.
macroevolution - correct answer ✔✔Changes produced only after many generations, such as the
appearance of a new species.
Mendelian traits - correct answer ✔✔Characteristics that are influenced by alleles at only one genetic
locus. Examples include many blood types, such as ABO. Many genetic disorders, including sickle-cell
anemia and Tay-Sachs disease, are also ________________.
microevolution - correct answer ✔✔Small changes occurring within species, such as changes in allele
frequencies.
phenotypes - correct answer ✔✔The observable or detectable physical characteristics of an organism;
the detectable expressions of genotypes, frequently influenced by environmental factors.
pigment - correct answer ✔✔In this context, a molecule that influences the color of skin, hair, and eyes.
polygenic - correct answer ✔✔Referring to traits that are influenced by genes at two or more loci.
Examples include stature, skin color, eye color, and hair color. Many (but not all) __________ traits are
influenced by environmental factors such as nutrition and exposure to sunlight.
