Honors Genetics
Chapter 4 Vocabulary
We learned several new vocabulary terms in Chapter 4 that we need to review. Below is a list of terms to
use to complete the Vocab Crossword Review provided; be sure to write the terms next to the definitions
as well as fill in the appropriate spaces in the Crossword Puzzle.
Bombay phenotype
codominance
conditional mutations
epistasis
expressivity
gene interaction
genetic anticipation
hemizygous
heterozygous
homozygous
incomplete dominance
lethal allele
maternal effect
multiple alleles
null allele
organelle heredity
penetrance
pleiotropy
sex-influenced inheritance
wild-type allele
X-linkage
Across
1. The allele that occurs most frequently in a population WILD-TYPE ALLELE
3. The range of expression of a mutant genotype EXPRESSIVITY
7. An offspring's phenotype is under the control of gene products in the egg MATERNAL EFFECT
9. Allele that results in complete loss of function NULL ALLELE
10. Genes that are inherited on the X chromosome show a unique inheritance pattern X-LINKAGE
11. The percentage of individuals that show some degree of expression of a mutant genotype
PENETRANCE
12. The intermediate expression of 2 different alleles (pink) INCOMPLETE DOMINANCE
13. The inheritance of identical alleles for a trait (HH, hh) HOMOZYGOUS
14. The expression of type O blood when the A or B allele is present BOMBAY PHENOTYPE
15. The expression of a single gene has multiple phenotype effects PLEIOTROPY
16. The progressively earlier onset and severity of a disorder from generation to generation GENETIC
ANTICIPATION
17. Extranuclear inheritance through the mitochondrial or chloroplast DNA HEREDITY
18. Expression of one gene or gene pair modifies the expression of another gene EPISTASIS
19. The joint expression of BOTH alleles in a heterozygote CODOMINANCE
20. When 3 or more alleles of the same gene are present that impact the phenotype expression
MULTIPLE ALLELES
21. A condition of males since they do not carry 2 homozygous sex chromosomes HEMIZYGOUS
Down
2. A mutation that results in the death of the organism, usually before they can reproduce LETHAL
ALLELE
4. The theory that several genes influence a characteristic GENE INTERACTION
5. Expression of genes is influenced by the sex hormone concentration of the individual SEX-
INFLUENCED INHERITANCE
6. The inheritance of 2 different alleles for a trait (Hh) HETEROZYGOUS
8. Phenotype expression is determined by environmental conditions CONDITIONAL MUTATIONS