An Introduction to the

Science of Botany

Chapter 1

TTU MS 43131

LEARNING OBJECTIVES

Briefly describe the field of botany, and give short definitions of at least five subdisciplines of plant biology

Summarize and discuss the features of plants and other organisms that distinguish them from nonliving things

Distinguish among the six kingdoms and three domains, and give representative organisms for each

Summarize the main steps in the scientific method, and explain how science differs from many other human endeavors

LEARNING OBJECTIVE 1

Briefly describe the field of botany, and give

short definitions of at least five subdisciplines

of plant biology

KEY TERMS

BOTANY The scientific study of plants; also

called plant biology

Subdisciplines 1

Plant molecular biology

Structures and functions of important biological

molecules (proteins, nucleic acids)

Plant cell biology

Structures, functions, and life processes of plant

cells

Subdisciplines 2

Plant physiology

How plants function (photosynthesis, mineral

nutrition)

Plant genetics

Plant heredity and variation

Subdisciplines 3

Plant ecology

Interrelationships among plants, and between plants

ands their environment

Overgrazing in Africa

p. 5

p. 7

LEARNING OBJECTIVE 2

Summarize and discuss the features of plants

and other organisms that distinguish them from

nonliving things

KEY TERMS

PHOTOSYNTHESIS

Biological process that includes capture of light

energy and its transformation into chemical energy

of organic molecules that are manufactured from

carbon dioxide and water

CELLULAR RESPIRATION

Cellular process in which energy of organic

molecules is released for biological work

KEY TERMS

DEOXYRIBONUCLEIC ACID (DNA)

A nucleic acid present in a cell’s chromosomes that

contains genetic information

KEY TERMS

EVOLUTION

Cumulative genetic changes in a population of

organisms from generation to generation

NATURAL SELECTION

Mechanism of evolution (Charles Darwin)

Tendency of organisms that have favorable

adaptations to their environment to survive and

become parents of next generation

Levels of Biological Organization

BiosphereAtoms

Hydrogen Oxygen

Molecule

Water

MacromoleculeChloroplast

Organelle

Epidermis

Tissue

Cell

Organ

Organism

Population

Community

Ecosystem

Fig. 1-3, p. 9

Characteristics of Living Things 1

Organization

Plants and other organisms are highly organized with

cells as their basic building blocks

Energy

Plants and other organisms take in and use energy

Plant Cells

Photosynthesis

Characteristics of Living Things 2

Interaction with environment

Plants respond to stimuli in their environment

Plants undergo growth and development

Reproduction

Plants form new individuals by asexual or sexual

reproduction

Root Growth and Gravity

Response to Stimuli

Germination

Asexual Reproduction

Characteristics of Living Things 3

Heredity

DNA molecules transmit genetic information from

one generation to the next in plants and other

organisms

Evolution

Plants and other organisms evolve

Populations change or adapt to survive in changing

environments

Adaptation

LEARNING OBJECTIVE 3

Distinguish among the six kingdoms and three

domains, and give representative organisms for

each

KEY TERMS

SPECIES

A group of organisms with similar structural and

functional characteristics

In nature, they breed only with one another and have

a close common ancestry

KEY TERMS

KINGDOM

A broad taxonomic category made up of related

phyla; many biologists currently recognize six

kingdoms of living organisms

DOMAIN

A taxonomic category that includes one or more

kingdoms

Organisms are classified into a

hierarchy

The main categories of classification are:

Domains,

Kingdoms,

Phyla,

Classes,

Orders,

Families,

Genera, and

Species. (e.g. house, street, city, county, state, country, continent, planet)

King Phillip Came Over Fearing Green Snakes

Three-Domain Classification

Archaea

Kingdom archaea

Bacteria

Kingdom bacteria

Eukarya

All other kingdoms

Euglena

Kingdoms and Domains

Six-Kingdom Classification 1

1. Archaea

2. Bacteria

3. Protista

protozoa, algae, water molds, slime molds

Six-Kingdom Classification 2

4. Fungi

molds, yeasts

5. Animalia

6. Plantae

Three Domains:

Bacteria Archaea Eukarya

Six Kingdoms:

Bacteria Archaea Protista Plantae Animalia Fungi

Prokaryotes (lack

membrane-bound

organelles);

unicellular;

most are

heterotrophic

(obtain food by

eating other

organisms),

but some are

photosynthetic or

chemosynthetic

Prokaryotes;

unicellular;

microscopic;

most live in

extreme

environments;

differ in

biochemistry

and in cell wall

structure

from bacteria

Eukaryotes;

mainly

unicellular or

simple

multicellular;

maybe

heterotrophic

or photosynthetic;

include protozoa,

algae, and slime

molds

Eukaryotes;

multicellular;

photosynthetic;

life cycle with

alternation of

generations;

cell walls of

cellulose

Eukaryotes;

multicellular;

heterotrophic;

most move

about by

muscular

contraction;

nervous

system

coordinates

responses to

stimuli

Eukaryotes;

most

multicellular;

heterotrophic;

absorb

nutrients;

do not photo-

synthesize;

cell walls of

chitin

Fig. 1-11, p. 14

Classification (Binomial System)

LEARNING OBJECTIVE 4

Summarize the main steps in the scientific

method, and explain how science differs from

many other human endeavors

KEY TERMS

HYPOTHESIS

An educated guess (based on previous observations)

that may be true and is testable by observation and

experimentation

THEORY

A widely accepted explanation supported by a large

body of observations and experiments

The Scientific Method 1

1. Recognize a problem

or an unanswered question

2. Develop a hypothesis

to explain the problem

3. Design and perform an experiment

to test the hypothesis

The Scientific Method 2

4. Analyze and interpret the data

to reach a conclusion

5. Share new knowledge

with the scientific community

Charles Darwin’s experiment withstems detecting light. Charles Darwin published his results on a number of different scientific studies in addition to his works on evolution. Through experimentation, he discovered that the tip of a stem detects light. (a) If the tip is covered, the stem does not grow toward the light. (b) If uncovered, the tip bends in the direction of the light.

Forming and testing hypotheses. The scientific method consists of observations that lead to a question. One or morehypotheses tentatively answer the question. Each hypothesis is thentested by experiments, which either support it or do not support it.Based on experimentation, the hypothesis is either accepted or rejected.

Conservation Biology

Extinction as a consequence of human activities

Loss of Plant and Animal habitats