Bio 189: Chapter 1 - Scientific Study of Life

Domain in the taxonomic hierarchy of life

- Eukarya - Archaea - Bacteria

Which has all the characteristics of life?

- a bacterial cell - a breathing rabbit

Biological organization from smallest at the top to the largest at the bottom

- atom - molecule - organelle - cell - tissue - organ

Cell

- basic unit of life - consists of a membrane enclosing water, DNA, and other chemicals

Discovery science

- carefully observing animals in nature without manipulation to them or their setting - studying trends in diseases to reveal that the incidence of diabetes is correlated with incidence obesity

Which questions can be answered by scientific experiments?

- does a new brand of cosmetics cause skin cancer? - does excess sugar lead to weight gain?

Eukarya

- domain consisting of all organisms that have a nucleus; includes protists, plants, fungi, and animals - unicellular and multicellular

Characteristics of life

- energy use - evolution - organization - reproduction, growth, and development - homeostasis, or maintenance of internal constancy

Characteristics of a scientific theory

- falsifiable - widely accepted and supported - encompass multiple hypotheses - can be used to make predictions

Stages of development (earliest stage at the top)

- fertilized egg - embryo - adult

Qualities of a scientific hypothesis

- it can lead to specific predictions - it must be testable

Experiment

- placing cells in different nutrient solutions to test a cell growth hypothesis - test a hypothesis under controlled conditions

Scientific method in order

1. observation and ask questions 2. hypothesis to explain observations and make predictions 3. carry out experiments to test the hypothesis and collect data 4. analyze your data and draw conclusions

Natural selection

A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits.

Evolution

a change in the genetic makeup of population over time

Variable

a changeable element of an experiment

DNA

a complex molecule containing the genetic information that makes up the chromosomes.

Theory

a comprehensive, well-accepted explanation of a natural phenomenon

Standardized Variable

a parameter of the experiment that is held constant

Hypothesis

a tentative, narrow-in-scope explanation of a natural phenomenon

Organelles

a tiny cell structure that carries out a specific function within the cell

Organisms seem so well-suited to their environments because they have inherited characteristics or behaviors, called ___, that enable them to successfully survive and reproduce

adaptations

Community

all the populations of different species that live in an area

Control

an experiment that is untreated and provides a basis of comparison

Tissues

are groups of specialized cells that function together

In ___ reproduction genetic information comes from only one parent; whereas, in ___ reproduction, genetic information from two parents unites to form an offspring

asexual; sexual

What are the small chemical units that can combine to form molecules?

atoms

Primary producer

autotroph that obtains energy an nutrients from nonliving sources

Species

basic unit of classification and is denoted by a unique two part scientific name

Sharing and sending blood away from the surface are examples of the human body maintaining a relatively constant ___ as part of homeostasis

body temperature

A living thing, or organism, exhibits certain properties of life and is composed of one ore more ___, the basic units of life.

cells

In a scientific study, collecting and interpreting the data allows investigators to

decide if evidence supports the hypothesis

The cell's genetic instructions are encoded in molecule called ___, and these instructions are used to produce proteins and allow the cell to carry out specialized functions

deoxyribonucleic acid (DNA)

One difference between domain Bacteria from organisms in the domain Archaea

difference in DNA sequences

Conscious thought is a(n) ___ that arises from the interactions among brain cells and neural structures in a human

emergent property

All living things are composed of one or more cells, use ___ to grow and reproduce, and maintain of state of internal constancy

energy

Technology

example of a practical application of scientific knowledge

Molecule

group of atoms bonded together

Consumer

heterotroph that obtains energy and nutrients by eating other organisms

Decomposer

heterotroph that obtains energy and nutrients from wastes and dead organisms

Fungi

heterotrophs; obtain food by external digestion

Animalia

heterotrophs; obtain food by ingestion

Using a process called ___, living organisms maintain a state of internal constancy or equilibrium, such as a constant range of temperatures, nutrients, or water.

homeostasis

Ecosystem

includes living and nonliving components of a particular area

Placebo

inert substance given to a portion of the experimental groups to act as a control

Experiement

is an investigation carried out under controlled conditions to test a hypothesis

___ is characterized by cellular organization, energy requirements, homeostasis, reproduction, growth, development, and evolution.

life

Plantae

multicellular; almost all are autotrophic organisms

Organ systems

multiple organs are linked together

Prediction

often written as an if-then statement

What is a structure consisting of tissues organized to interact and carry out specific functions?

organ

Biosphere

part of Earth in which life exists including land, water, and air or atmosphere

A group of the frogs in one of the ponds, NOT including the other species of organisms living there, is an example of

population

Peer review

scientists evaluate the validity of the research in scientific paper has been submitted for publication

When examining evolutionary relationships, taxonomists classify organisms according to

shared common ancestors

Metabolism

the chemical reactions within a cell

Independent Variable

the manipulated portion of the experiment

Sample size

the number of individuals in a sample

Dependent Variable

the response that an investigator measures

Taxonomy

the science of naming and classing organism

Prostista

unicellular and multicelluar organisms; autotrophic and heterotrophic organisms