Holt McDougal Biology Chapter 1

biosphere

All living things and all the places they are found on Earth.

biodiversity

The variety of life.

species

Particular type of living things that can reproduce by interbreeding among themselves.

biology

The scientific study of all forms of life, or all types of organisms.

organism

Any individual living things.

cell

The basic unit of life.

metabolism

All of the chemical processes that build up or break down materials.

DNA

In all organisms, the genetic material is a molecule called deoxyribonucleic acid.

system

An organized group of related parts that interact to form a whole.

ecosystem

A physical environment with different species that interact with one another and with nonliving things.

homeostasis

The maintenance of constant internal conditions in an organism.

adaption

An inherited trait that gives an advantage to individual organisms and is passed on to future generations.

observation

Using our senses to study the world, but it may also involve other tools.

data

observations and measurements recorded during an experiment.

hypothesis

Proposed answer for a scientific question.

experiment

Scientists study factors called independent variables and dependent variables to find cause-and-effect relationships.

independent variable

In an experiment is a condition that is manipulated, or changed, by a scientist.

dependent variable

Observed and measure during an experiment; they are the experimental data.

constants

The conditions that do not change during an experiment.

theory

Proposed explanation for a wide range of observations and experimental results that is supported by a wide range of evidence.

microscope

Provides an enlarged image of an object.

gene

A segment of DNA that stores genetic information.

molecular genetics

The study and manipulation of DNA on a molecular level.

genomics

The study and comparison of genomes both within and across species.

biotechnology

The use and application of living things and biological processes.

transgenic

Organisms that have genes from more than one species, or have altered copies of their own genes.