Activities Key Terms Quizzes Art Chapter 12 Self-Quiz
Unit 3: Genetics Patterns of Inheritance Review
  1. Genes are sequences of on chromosomes and form the basic units of inheritance. Genes determine observable , or characters, of an organism by coding for .
  2. Alleles are alternative versions of a gene caused by changes in the DNA called . Each organism has two alleles for a given gene. One inherited from the maternal side, and the other from the paternal parent.
  3. The exact combination of an organism's alleles for a given gene is referred to as its . The organism's observable traits that result from the genotype is called its
  4. If the two copies alleles for a gene are the same, the genotype is , otherwise it is .
  5. An allele that determines phenotype when combined with another allele is said to be An allele that does not express its phenotypic effect when combined with a dominant allele is said to be .
  6. Gregor Mendel's experiments with peas demonstrated the law of equal : one member of an allele pair ends up in one gamete during meiosis , and the other in a different gamete. This allows us to calculate the probabilities of the genotypes and phenotypes of the F1 generation from a genetic cross using the Punnett method.
  7. In most cases, allele segregation occurs independently for different genes due to random distribution of chromosomes into gametes during meiosis; this is the law of independent .
  8. The Punnett Square cam be used to calculate the of segregating multiple alleles in the F1 generation. A genetic cross involving 2 independent traits is called a cross.
  9. Although in some cases the is caused by a single gene, in most instances phenotype is determined by the interaction of multiple genes and the environment.

Activities Key Terms Quizzes Art Chapter 13 Self-Quiz
Unit 3: Genetics Chromosomes and Human Genetics Review
  1. The chromosomal theory of inheritance states that genes are located on . The specific region on a chromosome where a gene is found is called the gene . Chromosomes usually exist in pairs. This pairing means that in each cell there are two for each gene.
  2. Humans have X and Y sex chromosomes; the other 44 chromosomes are called . Females have two chromosomes, and males have one and one . The Y chromosome contains a specific gene whose product is necessary for male development.
  3. Genes that are located close together on a chromosome tend to be inherited as a group. Such clusters are known as genes , and do not exhibit independent assortment.
  4. During meiosis, genetic material can be exchanged between homologous pairs of chromosomes in a process called . This potential, together with mutations, the independent assortment of chromosomes during meiosis, and fertilization, results in genetic .
  5. Recombination produces offspring that are genetically different from either parent. This genetic in human populations provides the variation that fuels .
  6. In humans, most genetic diseases such as cystic fibrosis are and originate as of single genes.
  7. Huntington's disease is caused by a a allele; this disease is unusual in that its symptoms start late in life, after the normal reproductive age.
  8. of genetic diseases can be shown on a pedigree. A person heterozygous for a recessive genetic disorder is a for the disease.
  9. When a gene is located on a sex chromosome, it is said to be . Examples include hemophilia and muscular dystrophy. Congenital Generalized (CGH) is an X-linked gene.
  10. Inherited disorders can also be caused by abnormalities in chromosome , such as 21 in Down's Syndrome, or in chromosome , such as deletion of a region in chromosome 5 in Cri du Chat Syndrome.
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