Biology Genetics Test Review

Biology Genetics Test Review 1. What is a genotype? - Answer: The genotype refers to the specific genetic composition of an organism. 2. How is phenotype defined? - Answer: Phenotype describes the observable characteristics or traits of an organism. 3. What does allele mean? - Answer: An allele is a variant form of a gene found within the DNA. 4. What are genes? - Answer: Genes serve as the fundamental units of hereditary information in DNA. 5. What does it mean to be homozygous? - Answer: An individual is considered homozygous when they have identical alleles for a particular gene. 6. What is heterozygous? - Answer: Heterozygous refers to having two different alleles for a specific trait. 7. What characterizes a dominant trait? - Answer: Dominant traits will always be expressed in the phenotype whenever they are part of the genotype. 8. How is a recessive trait characterized? - Answer: Recessive traits will appear in the phenotype only when no dominant traits are present in the genotype. 9. What is a Punnett Square? - Answer: A Punnett Square is a tool used to illustrate all possible genotypes produced from a genetic cross. 10. What does incomplete dominance refer to? - Answer: Incomplete dominance occurs when the phenotype of a heterozygous individual is a blend of the two homozygous phenotypes. 11. What are multiple alleles? - Answer: Multiple alleles indicate that a single gene can have various forms, but only two of those can be inherited by an organism. 12. How do you define codominance? - Answer: Codominance describes a situation where two dominant traits are both fully expressed in the resulting phenotype. 13. What does sex-linked refer to? - Answer: Sex-linked genes are those located on the X or Y chromosomes. 14. What is meiosis? - Answer: Meiosis is a form of cell division that results in four genetically different haploid cells, primarily involved in sexual reproduction. 15. What is crossing-over? - Answer: Crossing-over involves the exchange of genetic material between homologous chromosomes, contributing to genetic diversity in offspring. 16. How is probability defined in genetics? - Answer: Probability is the measure of how likely an event is to occur. 17. What is the Product Rule (multiplication) in genetics? - Answer: The Product Rule is used to calculate the likelihood of two independent events occurring together. 18. What is the Sum Rule (addition) in genetics? - Answer: The Sum Rule is applied to determine the odds of either of two possible outcomes happening. 19. What are the potential gametes for an organism with genotype AaBBCc? - Answer: The possible gametes are ABC, ABc, aBC, and aBc. 20. For a TtRr pea plant, what different gametes can it produce? - Answer: The possible gametes from a TtRr plant are TR, Tr, tR, and tr. 21. Who is recognized as the Father of Genetics? - Answer: Gregor Mendel is known as the Father of Genetics. 22. How do organisms achieve genetic diversity in the next generation? - Answer: Two primary mechanisms for achieving variety are crossing-over and random assortment during meiosis. 23. What does polygenic mean? - Answer: Polygenic traits are influenced by multiple genes, affecting a physical characteristic. 24. What occurs during mitosis? - Answer: Mitosis is a process where a single cell divides to produce two genetically identical diploid daughter cells. It plays a role in growth, repair, and asexual reproduction and maintains the same number of chromosomes. 25. What distinguishes meiosis from mitosis? - Answer: Meiosis consists of two rounds of cell division, resulting in four genetically diverse haploid cells, specifically for sexual reproduction, and reduces chromosome numbers by half. 26. What are autosomal chromosomes? - Answer: Autosomal chromosomes are any chromosomes that are not sex chromosomes. 27. What is a karyotype? - Answer: A karyotype is an organized profile of an individual's complete set of chromosomes, arranged in homologous pairs. 28. In a pedigree chart, what shapes represent males and females? - Answer: A circle represents females, while a square represents males.