Life, Cells, and Classification Exam Review

Flashcards covering key concepts from lecture notes on Life, Cells, and Classification, including spontaneous generation, levels of organization, evolution, cell structure, and biological classification.

What did Francesco Redi's experiments aim to disprove?

Spontaneous generation, the idea that living organisms could arise from non-living matter.

Describe Francesco Redi's experiment to disprove spontaneous generation.

He placed meat in three jars: one open (control), one sealed, and one covered with gauze. Maggots only appeared on the meat in the open jar and on the gauze of the covered jar, but not in the sealed jar, suggesting flies, not the meat, produced the maggots.

Which scientists contributed to the debate about spontaneous generation after Redi?

John Needham, Lazzaro Spallanzani, and Louis Pasteur.

How did Louis Pasteur's experiment with swan-neck flasks definitively disprove spontaneous generation?

He boiled broth in swan-neck flasks to sterilize it. Air could enter, but dust and microbes were trapped in the curved neck, preventing growth in the broth. Only when the neck was broken or tilted, allowing microbes to contact the broth, did growth occur, demonstrating biogenesis.

List the biological levels of organization from simplest to most complex.

Atom, Molecule, Organelle, Cell, Tissue, Organ, Organ System, Organism, Population, Community, Ecosystem, Biosphere.

What is the difference between geologic evolution and organic evolution?

Geologic evolution refers to the changes in the Earth's physical features over time, while organic evolution refers to the genetic changes in populations of living organisms over time.

Name five lines of evidence that support the theory of evolution.

Fossils, comparative anatomy, embryology, molecular similarities (DNA/protein), and geographic distribution.

Define homologous structures.

Structures that have similar underlying anatomy due to shared ancestry but may have different functions (e.g., bat wing, human arm).

Define analogous structures.

Structures that have similar functions but different underlying anatomy, evolving independently due to similar environmental pressures (e.g., bird wing and insect wing).

What are vestigial structures?

Structures that have lost most or all of their original function through evolution but are retained in the organism (e.g., human appendix, wisdom teeth).

Why are cell surface area and cell size important for cell function?

Cell size is limited because surface area must be large enough to allow for efficient nutrient uptake and waste removal relative to the cell's volume. A higher surface area-to-volume ratio is more efficient.

What are the main components of a cell membrane?

A phospholipid bilayer with embedded proteins, cholesterol, and carbohydrates.

Describe the polar and non-polar parts of a phospholipid in the cell membrane.

The 'head' is hydrophilic (polar) and faces the aqueous environment, while the 'tails' are hydrophobic (non-polar) and orient towards the inside of the bilayer, away from water.

List three key differences between a plant cell and an animal cell.

Plant cells have a cell wall, chloroplasts, and usually a large central vacuole, which animal cells lack. Animal cells may have centrioles, which plant cells typically lack.

What is taxonomy?

The scientific study of how living things are classified, named, and grouped based on their characteristics and evolutionary relationships.

Who is considered the 'father of modern taxonomy' and developed binomial nomenclature?

Carolus Linnaeus.

What are the hierarchical levels of classification in order from broadest to most specific?

Kingdom, Phylum, Class, Order, Family, Genus, Species (KPCOFGS).

What are cladograms used for in phylogenics?

Cladograms are diagrams that show hypothetical evolutionary relationships among groups of organisms, illustrating patterns of shared ancestry and evolutionary divergence.

What is a dichotomous key used for?

A tool used to identify unknown organisms or objects by presenting a series of choices between two alternative characteristics at each step.

What is Biology?

The scientific study of life.

What is the difference between a scientific theory and a scientific law?

A scientific theory is a well-substantiated explanation of some aspect of the natural world, supported by a vast body of evidence, while a scientific law is a description of an observed phenomenon, often expressed mathematically, but does not explain 'why' it occurs.

List at least five of the nine characteristics of life.

Order/Organization, Response to stimuli, Reproduction, Adaptation through evolution, Growth and development, Regulation/Homeostasis, Energy processing/Metabolism, Genetic material (DNA/RNA).

What is the primary energy requirement for maintaining biological organization?

Living organisms require a continuous input of energy to maintain their complex organization and carry out life processes, combating the natural tendency toward disorder (entropy).

What is the difference between abiogenesis and biogenesis?

Abiogenesis is the hypothetical process by which life arose from non-living matter, while biogenesis is the principle that living organisms descend from other living organisms.

What was the key contribution of Antonie van Leeuwenhoek to biology?

He is often called the 'Father of Microbiology' for his pioneering work in microscopy and first observing and describing single-celled organisms, which he called 'animalcules'.