Meiosis & Mendelian Genetics

What is the difference between genotype and phenotype?

• There is no difference between genotype and phenotype

• Phenotype determines the genotypes

• Phenotype describes the genes; genotype describes the physical characteristics

• Genotype describes the genes; phenotype describes the physical characteristics

Which statement best describes the relationship between an allele and a gene?

• An allele is a variation of a gene that can be expressed as a phenotype

• An allele is the part of a gene that attaches to messenger RNA molecules

• An allele is a segment of a DNA molecule that controls replication of a gene

• An allele is the primary protein made by a gene found in a developing embryo

Unlike mitosis, meiosis results in the formation of:

• Body cells

• Haploid cells

• Diploid cells

• 2N daughter cells

The presence of a specific trait is genetically inherited. There are only 2 possible outcomes for this trait: an individual either inherits the trait or does not inherit the trait. Which statement best describes how parents influence this trait?

• Each parent contributes 2 genes for this trait

• Each parent contributes one allele for this trait

• Each parent contributes 2 chromosomes for this trait

• Each parent contributes one nitrogenous base for this trait

What are Punnett squares used for?

• Predicting the result of genetic crosses between organisms of known genotypes

• Identifying the gene location where variations in the alleles are possible

• Determining exactly what all offspring will look like

• Determining the DNA sequence of a given gene

Chromosome A contains genes for an eye color of hazel. Chromosome B contains genes for hair color of hazel, and chromosome C contains genes for an eye color of blue.

• Chromosomes A and B are homologous

• Chromosomes B and C are homologous

• Chromosomes A and C are homologous

• None of the chromosomes are homologous to one another

During meiosis I,

• Homologous chromosomes separate

• Each sister chromatid becomes a chromosome

• Sister chromatids separate

• 4 daughter cells are formed from a single original cell

Sexual reproduction involves the processes listed below: A. Differentiation B. Fertilization C. Gamete production D. Mitosis Which sequence represents the order in which these processes occur?

• A. A -> B -> C -> D

• B. B -> A -> C -> D

• C. C -> B -> D -> A

• D. D -> B -> C -> A

These homologous chromosomes carry different alleles of the wild type and mutant type in the fruit fly Drosophila. A cell with the homologous chromosomes undergoes meiosis, and gametes are produced. Is it possible for a chromosome of a gamete to contain the alleles for gray body and brown eyes?

• A. Yes, because chromosomes are not generally inherited as units

• B. Yes, because homologous chromosomes may exchange segments by crossing over during meiosis

• C. No, because chromosomes are always inherited as complete units

• D. No, because crossing over occurs only during mitosis, not meiosis

A species in a changing environment would have the best chance of survival as a result of a mutation that has a A. high adaptive value and occurs in its skin cells B. low adaptive value and occurs in its skin cells C. high adaptive value and occurs in its gametes D. low adaptive value and occurs in its gametes

• A. Low adaptive value and occurs in its skin cells

• B. High adaptive value and occurs in its skin cells

• C. High adaptive value and occurs in its gametes

• D. Low adaptive value and occurs in its gametes