Practice+Quiz+4

Ellie Cheromcka Genetics- Quiz Review Questions 1.    What is the difference between dominant and recessive genes? 2.    What is the difference between homozygous and heterozygous? 3.    Describe Mendel’s Laws. 4.    What is an allele? 5.    What is an example of a genotype? 6.    What is a test-cross? 7.    What is condominance? 8.    What are polygenic traits? 9.    What is a diploid and what is a haploid?

10.    What is meiosis?

11.    How many chromatids are in a tetrad? 12.    What is mitosis? 13.    What is probability? 14.    What are gametes? 15.    What are hybrids? **

1  A-    **  Dominant genes produce the same phenotype in the organism whether or not its allele is identical. A recessive gene is a gene that produces its characteristic phenotype only when its allele is identical.

2  A-    Homozygous is having identical pairs of genes for any given pair of hereditary characteristics. Heterozygous is having dissimilar pairs of genes for any hereditary characteristic.

3A- First Law- The Law of Segregation states that the members of each pair of alleles separate when gametes are formed.
 * Second Law- The Law of Independent Assortment states that two or more pairs of alleles segregate independently of one another during gamete formation.

4 A-Allele is any of several forms of a gene, usually arising through mutations that are responsible for hereditary variation.

5A- AA- homozygous dominant. Aa- heterozygous. aa- homozygous recessive. 6A- A test-cross is used to determine if an individual exhibiting a dominant trait is homozygous or heterozygous for that trait. 7A- Condominance is a situation in which both alleles of a gene contribute to the phenotype of the organism. 8A-     Traits that are controlled by two or more genes. 9A-    A diploid is a cell that contains both sets of homologous chromosomes. A Haploid is a cell that contains a single set of chromosomes. 10A-   A process of reduction division in which the number of chromosomes per cell is cut in half through the separation of homologous chromosomes in a diploid cell. 11A-   Four. 12A-   Mitosis results in the production of two genetically identical diploid cells, whereas meiosis produces four genetically different haploid cells. 13A-   Probability is the likelihood that a particular event will occur. 14A-   Gametes are specialized cells involved in sexual reproduction. 15A-   Hybrids are the offspring of crosses between parents with different traits. **  **  **