BIO 101 CH1 & CH2

Study of Life, Chemistry of Life

Biology is defined as __________.

The study of living organisms & their interactions with one another and their environment.

The smallest fundamental unit of structure & function in living organisms is called a __________.

Cell.

Prokaryotes are characterized as __________, while eukaryotes can be __________ or __________ and have nuclei.

unicellular; unicellular; multicellular

The simplest living organisms are __________, which mean one, such as bacteria, yeast, and amoebae.

unicellular.

In the scientific method, __________ are things that can be changed in a system that you are studying.

Variables.

The three parts of Cell Theory states that all living organisms are composed of __________, that cells are the __________ of life, and that cells come from __________ cells.

cells; basic unit; pre-existing.

In an experiment, the __________ variable is the one that is changed while the __________ variable is the one that is measured at the end.

Independent; dependent.

Valid sources of scientific information include peer-reviewed articles that contain __________, __________, materials & methods, results, and __________.

abstract; introduction; discussion.

The basic properties of living organisms include having order, being sensitive & responsive to stimuli, __________, growing and developing, having __________ and homeostasis, and processing __________.

reproducing; regulation; energy.

Order the hierarchy of living things starting from __________, going to __________, __________, cells, tissues, organs, organ systems, and ending with __________.

atoms; molecules; organelles; organism.

Atom

General term for the building blocks of matter.

Atomic mass/Mass number

The total number of protons and neutrons in an atom's nucleus.

Electronegativity

How much attraction an atom has for electrons, represented from 0-4, with 4 being the most electronegative.

Valence shell

The outermost shell of an atom, where atoms attempt to keep shells full, driving chemical reactions; relates to the octet rule.

Ionic bond

A chemical bond formed between atoms through the transfer of electrons.

Covalent bond

A chemical bond formed between atoms when one or more pairs of electrons are shared.

Hydrogen bond

Weak electrical attractions between molecules, often involving hydrogen atoms.

Sub-atomic particles

The main three particles in an atom: electrons (negative charge), protons (positive charge), and neutrons (no charge).

Cations

Positively charged ions formed when an atom loses electrons.

Anions

Negatively charged ions formed when an atom gains electrons.

Polar covalent bond

A bond where electrons are shared unequally, creating partial charges.

Non-polar covalent bond

A bond where electrons are shared equally between atoms.

Polarity of Water

Water is polar due to the electronegativity difference between oxygen (3.5) and hydrogen, leading to partial negative charges on oxygen.