BIOL 1002L Introductory Biology II Lab Review

Lab Safety Guidelines

  • No food or drink is allowed in the laboratory.

  • Bookbags should be placed on the side counter.

  • Sign-up sheet: Write your name on the designated sheet.

  • Protective clothing must be worn before entering the lab.

  • During labs, ensure the use of personal protective equipment (PPE).

  • Cleaning protocol: Clean your lab station with 70% alcohol and paper towels after use.

Nucleic Acid: DNA

  • Definition: DNA (Deoxyribonucleic acid) is the genetic code for all living organisms (plants, animals, fungi, protists, and bacteria).

  • Structure: DNA has a large, double-stranded structure resembling a double helix.

  • Function:

    • Acts as a set of instructions for building organisms.

    • Found in almost all cells of all organisms.

    • Is inherited from parents.

    • Essential for reproduction.

DNA Structure

  • Composed of nucleotides; each consists of:

    • Sugar: Deoxyribose

    • Phosphate group

    • Nitrogen Bases: Adenine (A), Thymine (T), Guanine (G), Cytosine (C).

  • Base Pairing Rules:

    • Adenine pairs with Thymine.

    • Guanine pairs with Cytosine.

Why Isolate DNA?

  • Applications include:

    • DNA sequencing

    • Paternity testing

    • Diagnosis of genetic disorders

    • Studying mutations

    • Gene function analysis

    • Gene therapy for diseases.

Procedure for DNA Extraction

  1. Materials Needed: Kiwi or strawberry, Ziplock bag, dish soap, water, salt, coffee filter, beaker, enzyme solution.

  2. Steps:

    • Cut fruit and mash in a Ziplock bag with soap, water, and salt.

    • Ice bath intervals for gentle processing.

    • Filter the mixture to collect filtrate.

    • Add enzyme solution, let sit, and separate using Ethanol to visualize DNA.

Human Genetics Overview

  • Human genome was sequenced in 2003, containing about 3 billion nucleotide bases.

  • DNA is organized into 23 pairs of chromosomes, encompassing approximately 30,000 genes.

  • Mutations can lead to genetic disorders or phenotypic variations.

Genetic Terms

  • Gene: Basic unit of heredity, containing information that affects a trait.

  • Allele: Different versions of a gene (e.g., fur color in dogs).

  • Phenotype: Observed characteristic based on genetic makeup.

  • Genotype: Genetic makeup of an individual.

  • Dominant: One allele masks another; represented by uppercase letters.

  • Recessive: An allele that is masked by a dominant allele; represented by lowercase letters.

Genetic Disorders

  • Types: Recessive, Dominant, X-linked disorders.

  • Chromosomal abnormalities include nondisjunction leading to conditions like Trisomy 21.

  • Karyotypes: Chromosome photographs used for analyzing genetic disorders.

Paternity Testing

  • Based on blood type compatibility and presence of antigens.

  • Blood types determined by presence of surface antigens on red blood cells.