BIOL 2107 – Principles of Biology I Exam 1 Review

These flashcards cover key concepts and definitions from the BIOL 2107 lecture notes related to biology's principles, focusing on the scientific method, cellular structures, evolution, chemical contexts, and membrane transport.

What are the steps of the scientific method?

Observations, question, hypothesis, experiment, analysis.

What defines a useful hypothesis?

It is testable, falsifiable, and based on prior knowledge.

When should a controlled experiment be used?

When the researcher manipulates one variable while keeping others constant to establish a cause-and-effect relationship.

What is entropy?

A measure of disorder or randomness in a system.

What are the common features shared by all life on Earth?

Cellular organization, metabolism, homeostasis, growth and development, reproduction, genetic information, evolution.

What is evolution in general terms?

The process where populations change over generations through variations in traits and differential survival and reproduction.

What is one piece of evidence that supports the history of life on Earth?

Fossil records provide chronological evidence of past life forms and their evolution.

What characteristics define covalent bonds?

They form when two atoms share one or more pairs of electrons.

What is the difference between polar and non-polar molecules?

Polar molecules have a polar covalent bond with an asymmetric shape, while non-polar molecules do not.

What is the pH scale?

It measures the concentration of hydrogen ions in a solution.

Why is water crucial for the chemistry of life?

Due to its polarity, cohesion, adhesion, high specific heat, and high heat of vaporization.

What is the primary reason carbon is central to life?

Its ability to form four covalent bonds allows it to create diverse and complex molecules.

What are the four major macromolecules of life?

Carbohydrates, proteins, nucleic acids, and lipids.

How are macromolecules formed?

Through polymerization, specifically using dehydration synthesis reactions.

What bonds link monosaccharides to form carbohydrates?

Glycosidic linkages.

What is the endosymbiotic theory?

It proposes that mitochondria and chloroplasts originated as free-living prokaryotes that were engulfed by a host cell.

How do phospholipids form cell membranes?

They spontaneously arrange into a bilayer with hydrophilic heads facing outwards and hydrophobic tails facing inwards.

What is passive transport?

The movement of substances across a membrane without the use of energy, down their concentration gradient.

What is the difference between active transport and passive transport?

Active transport requires energy and moves substances against their concentration gradient, while passive transport does not require energy.

What are aquaporins?

Specialized channel proteins that facilitate the rapid transport of water molecules across the membrane.

What role do membrane receptors play in cell signaling?

They detect external signals, bind ligands, and initiate cellular responses.