Chromosomes and Mutations

Describe the genome.

The whole of the genetic information of an organism.

State the relationship between genome size and organism complexity.

Sizes vary based on organism, not complexity.

Outline the outcomes of the human genome project.

Mapping of genes, screening for genetic diseases, improved medical treatments, and understanding origins and migration patterns.

Describe mapping in the human genome project.

Involves number, location, and basic sequence of genes.

Describe screening in the human genome project.

Detects sufferers and carriers of genetic diseases.

Describe medicine's impact from the human genome project.

Improved treatment for diseases.

Describe ancestry's impact from the human genome project.

Provides understanding of origins, evolution, and migratory patterns.

Describe a gene.

Length of DNA controlling a heritable characteristic.

Describe an allele.

Specific form of a gene.

Describe a gene mutation.

Change in nucleotide sequence in DNA coding for a particular feature.

List 3 causes of mutagens.

X Rays, cigarettes, HPV virus.

Outline the 3 different types of base substitutions.

Silent (does not alter amino acid sequence), Missense (causes incorrect amino acid), Nonsense (creates a premature stop codon).

Describe frameshift mutation.

Caused by insertion or deletion of a base, changes reading frame during protein synthesis, resulting in every amino acid being incorrect.

Describe block mutations.

Changes to entire sections of a chromosome causing large scale changes to DNA.

Distinguish between somatic and germ line mutations.

Somatic mutations (in body cells, cannot be passed to offspring) and germ line mutations (in gametes, can be passed to offspring).

Explain the causes and consequences of sickle cell anemia.

Caused by a missense mutation GAG to GTG, replacing glutamic acid with valine, resulting in fibrous hemoglobin and sickled red blood cells, leading to anemia and fatigue.

Describe a karyotype.

Number of chromosomes an individual has.

Describe a karyogram.

Visual profile of all chromosomes in a cell, arranged into homologous pairs.

Outline how a karyogram is created.

1. Harvesting cells, 2. Halting during metaphase, 3. Staining and photographing chromosomes, 4. Arranging according to structure.

Describe the #1 reason for analyzing a karyogram.

Test for chromosomal abnormalities (non-disjunction).

Describe ways to obtain fetal cells for a Karyogram.

Amniocentesis (sample amniotic fluid) and Chorionic villus sampling (sample chorionic villi from placenta).