Biol 101 Lab – Labs 1-4 Review

Biol 101 Lab – Labs: 1-4 - Review Document

This document serves as an organizational tool for review content related to Biol 101 Labs 1-4. Students are encouraged to refer to their lab notes on D2L, lab handouts, and lab exit documents to supplement this review.

Lab 1: Scientific Investigation

  1. Understanding the Scientific Method

    • Define the steps involved in the scientific method:

      • Observation: Noting phenomena or patterns.

      • Question: Formulating a question based on observations.

      • Hypothesis: Developing a testable prediction.

      • Experimentation: Designing and conducting experiments to test the hypothesis.

      • Data Collection: Gathering and analyzing data from the experiment.

      • Conclusion: Interpreting the data to accept or reject the hypothesis.

    • Characteristics of the Steps:

      • Each step must be methodical and reproducible.

    • Answering Scientifically: Only questions that can be tested through observation and experimentation can be addressed.

    • Increasing Validity: Scientists enhance validity by:

      • Using control groups and variables consistently.

      • Drafting precise and clear scientific questions.

    • Graphical Analysis: Ability to interpret graphs for hypothesis support or rejection.

  2. Controls and Variables

    • Independent Variables: The variable that is manipulated or changed during an experiment.

    • Dependent Variables: The variable that is observed and measured in response to changes in the independent variable.

    • Control Variables: Variables that are kept constant to ensure a fair test.

    • Distinction in Experiments: Understanding how to identify these variables in experiments and on graphs.

  3. Utilizing the Scientific Method

    • Experiment Completion: Follow the scientific method steps during lab experiments.

    • Hypothesis Non-support: Discuss actions to take if results do not support the initial hypothesis.

Lab 2: Cellular Chemistry

  1. Chemical Components of Cells

    • Macromolecules: Large molecules essential for structure and function in cells.

      • Common types include:

      • Proteins: Chains of amino acids with diverse functions.

      • Carbohydrates: Sugar molecules including simple sugars and polysaccharides.

      • Lipids: Fats and oils, important for cell membranes.

  2. Tests for Biomolecules

    • Carbohydrate Tests:

      • Monosaccharides: Benedict's test (positive: red/orange color)

      • Starches: Iodine test (positive: blue/black color)

    • Protein Test:

      • Biuret test (positive: purple color)

    • Lipid Test:

      • Paper test (positive: translucent spot)

  3. Identifying Unknown Chemicals

    • Ability to analyze experimental data to identify unknown substances.

    • Water as Negative Control: Water acts as a negative control to show the absence of a reaction.

  4. Positive vs. Negative Tests

    • Distinguishing between positive and negative results from lab tests performed.

Lab 3: DNA Investigation

  1. Gel Electrophoresis Analysis

    • Gel Products: Analyze DNA fragments based on size and charge; smaller fragments move faster.

    • Fragment Identification: Understanding how to measure and locate the number and position of DNA fragments in the gel.

  2. Data Analysis

    • Weighing evidence and interpreting data confidently from gel electrophoresis results.

    • Decision-making based on DNA analysis related to suspect exclusion/inclusion.

  3. Central Dogma Components

    • DNA Characteristics: Structure composed of double helix, base pairs (A-T, C-G).

    • RNA Characteristics: Single-stranded molecule with bases (A-U, C-G).

      • Nucleotide Structure: Phosphate group, sugar, and nitrogenous bases.

      • Complementary Base Pairing:

      • DNA: Adenine pairs with Thymine and Cytosine pairs with Guanine.

      • RNA: Adenine pairs with Uracil and Cytosine pairs with Guanine.

    • Flow of Information:

      • DNA -> RNA -> Protein

    • Codons: Triplet sequences in mRNA that specify amino acids.

    • Amino Acids from Codons: Use the Genetic Code chart for conversion.

    • Mutations: Changes in DNA sequence; can result in altered or unchanged amino acid sequences.

Lab 4: Probability and Genetics

  1. Predicting Inheritance with Punnett Squares

    • Definitions:

      • Alleles: Different versions of a gene.

      • Homozygous: Both alleles same (e.g., AA or aa).

      • Heterozygous: Two different alleles (e.g., Aa).

      • Dominant: Trait that appears in the phenotype.

      • Recessive: Trait that does not appear when dominant is present.

    • Genotypes and Phenotypes: Genotypes are genetic makeups underlying phenotypes, the observable characteristics.

    • Setting Up Punnett Squares: Methodical process to visualize potential offspring's genotypes.

  2. Gel Electrophoresis in Genetic Analysis

    • Analyze gels for genetic differences in traits, particularly the KIT gene.

    • Recognize variation in alleles (long vs. short) related to the KIT gene.

  3. Understanding Pedigrees

    • Components of pedigrees: Symbols representing individuals, generations, and relationships.

    • Solve genetic inheritance problems in pedigrees focusing on autosomal dominant and recessive traits.