Identification of Metals Lab Quiz

Identification of Metals Lab Overview

• Lab aimed to determine the density of an unknown metal through mass and volume relationship.
• Density formula used: D = m/v, highlighting proportional relationships between mass and volume.

Density and Graph Analysis

• Manual graph indicated that with constant volume, both density and mass increase proportionally.
• Average density calculated: 12 g/mL from points (0.40 mL, 6.274 g) and (1.0 mL, 13.729 g).
• Excel graph showed an average density of 12.7 g/mL, while manual calculation resulted in 14.0 g/mL.

Identification of Lead

• Closest element to calculated densities is Lead (Pb) with a known density of 11.342 g/mL.
• Both manual and Excel graphs displayed a straight line, indicating a positive linear relationship between mass and density.

Error Analysis

• Discrepancies noted between calculated averages and actual average density of Pb, indicating potential errors in measurement.
• Percent of error calculated:
  • Manual graph: 5.80%
  • Excel graph: 12%
  • Manual calculation: 23.4%
• Average percent error across three calculations: 13.7%, revealing significant deviations.

Sources of Error

• Inconsistent scale readings affected mass measurements, leading to variances in results.
• Potential issue with scale calibration contributed to inaccuracies.
• Volume measurement inaccuracies also cited as a source of error, impacting final results.

Core Concepts of Biodiversity

• Evolution has resulted in a vast diversity of life on Earth.
• A nomenclature system is essential for classifying and labeling organisms.
• Three primary domains of life established early in evolution:
  • Domain Bacteria - Prokaryotic organisms.
  • Domain Archaea - Prokaryotic organisms.
  • Domain Eukarya - Eukaryotic organisms.

Origin of Life

• The exact process of how life originated on Earth remains uncertain.
• The Universe began approximately 13-14 billion years ago with the Big Bang.
• Earth formed about 4.6 billion years ago; fossil evidence suggests life appeared around 3.5 billion years ago.
• The Miller-Urey experiment explored possible origins of life.

Types of Early Organisms

• Autotrophs are organisms that produce their own food; notable example: Cyanobacteria.
• Early landmasses: Laurasia and Gondwana.
• The Cretaceous extinction possibly caused by an asteroid impact.

Taxonomy and Classification

• Taxonomy is the science of naming and classifying species.
• Classification hierarchy (from broad to specific):
  • Kingdom
  • Phylum
  • Class
  • Order
  • Family
  • Genus
  • Species (example: Homo sapiens)

Domain Eukarya

• Eukaryotes possess mitochondria, which are non-photosynthetic in some cases and photosynthetic in others.
• Meiotic types of eukaryotes exist.

Kingdoms within Eukarya

• Kingdom Archaeozoa: Lacks mitochondria but contains nuclei.
• Kingdom Protista:
  • Noted for its diversity and polyphyletic nature.
  • Classification based on ecological roles:
    • Consumers (Heterotrophs)
    • Producers (Autotrophs)
    • Mixotrophs (Both)

Heterotrophic Protists

• Includes fungus-like "Water Molds" from Phylum Chytridiomycota and Phylum Oomycota.
• "Slime Molds" (Phylum Myxomycota) exhibit multinucleated structures, forming "one huge cell."
• "Cellular Slime Molds" (Phylum Acrasiomycota) form aggregates of cells with spore-producing structures (Sporangium).

Animal-Like Protists

• Exhibit pseudopodia (false feet), shells of calcium or silica.
• Examples include:
  • Amoebae
  • Radiolarians with siliceous shells.
  • Ciliates (Phylum Ciliophora) possess specialized organelles and complex cellular structures.
  • Zooflagellates (Phylum Mastigophora) are mostly parasitic.

Parasitic Protists

• Phylum Apicomplexa: Includes Plasmodium, responsible for malaria, primarily transmitted by mosquitos.
• Various life stages include:
  • Cryptozoite in the blood and liver.
  • Gametocyte forms for sexual reproduction.

Autotrophic/Heterotrophic Protists

• "Plant/Animal-Like":
  • Phylum Euglenophyta: Possesses chlorophyll A & B, lacks a cell wall, with a stigma (eyespot) for light detection.
  • Phylum Pyrrophyta (Dinoflagellates): Features chlorophyll A & C, two flagella, and includes bioluminescence.

Autotrophic Protists - "Plant-Like"

• Phylum Chrysophyta: Contains golden-brown algae (Chlorophyll A & C); some species have silica or pectin cell walls.
• Phylum Rhodophyta (Red Algae): Contains chlorophyll A & D, harvested for extracts like carrageenan and agar.
• Phylum Phaeophyta (Brown Algae): Contains chlorophyll A & C; features structures such as holdfast, stipe, and frond.
• Phylum Chlorophyta (Green Algae): Includes diverse assemblages and is considered a likely link to higher plants (e.g., Volvox, Codium).