Biol 1610 Lecture 2: Properties of Life and the Scientific Method

Flashcards covering key definitions of life, cellular types, biomolecules, and scientific method principles including experimental variables and controls from Lecture 2.

How did Joyce (1995) define life in the definition adopted by NASA?

Life is a self-sustained chemical system capable of undergoing Darwinian evolution.

How did Page (2001) define life?

Life is a self-replicating, evolving system based on organic chemistry.

What is the smallest unit that meets all fundamental properties of life?

A cell.

What are the main characteristics of prokaryotic cells?

They have no nucleus (no nuclear membrane), circular DNA, a small size between $0.1-5\text{ }\boldsymbol{\rm\mu m}$, often no membrane-bound organelles, and fast replication.

What are the main characteristics of eukaryotic cells?

They have a nucleus and membrane-bound organelles, linear DNA (chromosomes), and a size between $1-100\text{ }\boldsymbol{\rm\mu m}$.

Why are viruses not considered to be alive based on biological criteria?

Because they cannot reproduce or metabolize outside a host cell.

What are the four main biomolecules that support the properties of life?

Lipids, Nucleic Acids, Proteins, and Carbohydrates.

What is a scientific control?

An experiment designed to minimize the effects of variables other than the independent variable/causal factor being tested, keeping all other variables constant to increase reliability.

What is the difference between an independent variable and a dependent variable?

The independent variable is the causal factor being tested (plotted on the horizontal X-axis), while the dependent variable is what is measured that depends on the independent variable (plotted on the vertical Y-axis).

What does inductive reasoning involve in the scientific method?

Combining isolated facts into a cohesive whole to generate possible explanations.

What does deductive reasoning involve in the scientific method?

Making predictions based on models using an 'If…then' framework.

According to the Ebbinghaus Forgetting Curve, how much learned information is forgotten within one hour?

More than $50\%$ of what is learned is forgotten within one hour.

In the beach and inland mice study, what hypothesis was tested?

Different coloration patterns of beach versus inland mice evolved as adaptations that camouflage the mice in their native environments, protecting them from predation.

In the mouse camouflage experiment, what represented the control group?

The camouflaged mouse models placed in their native matching habitats (light models on the beach and dark models inland).

In the atrazine study on frogs, what was the concentration of atrazine in the control group?

$0\text{ ppb}$ (parts per billion).