Chapter 1 An Introduction To Life On Earth

Question 1

Biodiversity

Answer 1

The diversity of living organisms; measured as the variety of different species, the variety of different alleles in a gene pool, or the variety of different community interaction in a ecosystem.

Question 2

Cell

Answer 2

The smalles unit of life, consisting, at a minimum, of an outer membrane that encloses a watery medium containing organic molecules, including genetic material composed of DNA

Question 3

Community

Answer 3

All the interacting populations within an ecosystem.

Question 4

Conclusion

Answer 4

The final operation in the scientific method; a decision made abou the validity of a hypothesis on the basis of experimental evidence.

Question 5

Control

Answer 5

The portion of an experiment in which all possible variables are held constant; in contrast to the “experimental” portion, in which a particular varibale is altered.

Question 6

Deoxyribonucleic Acid (DNA)

Answer 6

A molecule composed of deoxyribose nucleotides; contains the genetic information of all cells.

Question 7

Energy

Answer 7

The capacity to do work.

Question 8

Evolution

Answer 8

(1) The theory that all species are related by common ancestry and have changed over time; (2) Any change in the proportions of different genotypes in a population from one generation to the next.

Question 9

Experiment

Answer 9

A fifth operation in the scientific method; the testing, by further observations, of a prediciton generated by a hypothesis, leading to a conclusion.

Question 10

Gene

Answer 10

A unit of heredity that encondes the information needed to specify the amino acid sequence of protiens and hence particular traits; a functional segment of DNA located at a particular place on a chromosone.

Question 11

Hypothesis

Answer 11

The third operation in the scientific method; a supposition based on a pervious observations that is offered as an explanation for the observed phenomenon and is used as the basis for further observations or experiments.

Question 12

Natural Selection

Answer 12

The process in which unqeual survival and reproduction of organisms, favoring indiviuals with particular traits, causes those traits to become increasingly common in a population.

Question 13

Observation

Answer 13

The first operation in the scientific method; noting of a specific phenomenon, leading the formulation of a question.

Question 14

Organ

Answer 14

A structure (such as the liver, kidney, or skin) composed of two or more distinct tissue types that function together.

Question 15

Organism

Answer 15

An individual living thing.

Question 16

Photosynthesis

Answer 16

The complete series of chemical reactions in which the energy of light is used to synthesize high-energy organic molecules, normally carbohydrates, from low-energy inorganic molecules, normally carbon dioxide and water.

Question 17

Population

Answer 17

All the members of a species that occupy a particular area at the same time.

Question 18

Prediction

Answer 18

A fourth operation in the scientific method; a statement describing an observable outcome that would occur if a particular hypothesis were true.

Question 19

Question

Answer 19

The second operation in the scientific method; a query that identifies a particular aspect of an observation that a scientist wishes to explain.

Question 20

Scientific Method

Answer 20

A rigorous procedure for making observaions of specific phenomena and searching for the order underlying those phenomena; consists of six operations: observation, question, hypothesis, prediction, experiment, conclusion.

Question 21

Scientific Theory

Answer 21

A general explanation of natural phenomena devoloped through extensive and reproducible observations; more general and reliable than a hypothesis.

Question 22

Species

Answer 22

The basic unit of taxonomic classification, consisting of a group of populations that evolves independently. In sexually reproducing organisms, a species can be defined as a population or series of populations of organisms that interbreed frely with one another under natrual conditions but that do not interbreed with members of other species.

Question 23

Tissue

Answer 23

A group of (normally similar) cells that together carry out a specific function; for example, muscle; may include extracellular material produced by its cells.

Question 24

Variable

Answer 24

A condition, particularly in a scientific experiment, that is subject to change.