BIOL Chap 1

What is taxonomy?

The science of classifying different organisms.

Why is taxonomy useful?

It helps scientists identify organisms, communicate universally, and group organisms based on similarities and differences.

Who is considered the father of taxonomy?

Carl Linnaeus.

What did Carl Linnaeus contribute to biology?

He introduced a system for organizing, classifying, and naming organisms and popularized binomial nomenclature.

What was Linnaeus’s original classification based on?

Common physical characteristics, especially whether an organism moved or did not move.

What is binomial nomenclature?

A two-name system for naming organisms using the genus and species/specific epithet.

What two parts make up a scientific species name?

The genus name and the specific epithet/species name.

How should a scientific name be formatted?

The genus is capitalized, the species is lowercase, and both words are italicized or underlined.

In Homo sapiens, which word is the genus?

Homo.

In Homo sapiens, which word is the species/specific epithet?

sapiens.

How can a genus be abbreviated in binomial nomenclature?

The genus can be shortened to its first letter, such as Escherichia coli becoming E. coli.

Why does binomial nomenclature provide a universal language?

It gives organisms one consistent scientific name even when common names differ across languages or regions.

What were the two original kingdoms in early classification?

Plantae and Animalia.

How were plants originally classified?

They stayed in one place and used light energy to make their own food through photosynthesis.

What is an autotroph?

An organism that makes its own food, often using light energy through photosynthesis.

How were animals originally classified?

They moved around and obtained food from the environment.

What is a heterotroph?

An organism that obtains food by consuming or absorbing materials from the environment.

Why did the original two-kingdom system become a problem?

Microscopes revealed organisms that did not fit neatly into plants or animals.

What are amoebas?

Single-celled organisms that can move around and did not fit well into the original plant/animal system.

Who proposed the five-kingdom classification system?

Robert Whittaker.

What is morphology?

The study or description of an organism’s shape or physical appearance.

What was Kingdom Protista used for?

It was a catch-all group for single-celled organisms that did not fit easily into Plantae or Animalia.

Why is the term protist considered controversial or partly obsolete?

Because Protista was used as a broad catch-all group rather than a precise evolutionary grouping.

Why were fungi separated from plants?

Fungi do not photosynthesize; they absorb nutrients from dead or decaying material.

What are decomposers?

Organisms that break down dead plants and animals and recycle nutrients.

What is an example of a unicellular fungus?

Baker’s yeast.

What is an example of a multicellular fungus?

Mushrooms.

What major cell types were distinguished after advances in microscopy?

Prokaryotes and eukaryotes.

What was Kingdom Monera?

A kingdom added to include prokaryotic organisms such as bacteria.

Why was Kingdom Monera later considered too simplistic?

DNA/RNA evidence showed that organisms placed in Monera were more diverse than originally thought.

Who proposed the three-domain system?

Carl Woese.

What are the three domains of life?

Bacteria, Archaea, and Eukarya.

What organisms are included in Domain Eukarya?

Eukaryotic organisms, including plants, animals, fungi, and protists.

What is a eukaryotic cell?

A cell with DNA enclosed inside a membrane-bound nucleus.

What is a prokaryotic cell?

A cell whose DNA is not enclosed in a membrane-bound nucleus.

Where is genetic material located in prokaryotes?

In a nucleoid region, not inside a membrane-bound nucleus.

What distinguishes Domain Bacteria from Domain Archaea?

Bacteria have peptidoglycan in their cell walls; Archaea do not.

What is peptidoglycan?

A substance found in bacterial cell walls.

Where are Archaea commonly found?

Extreme environments such as volcanoes, glaciers, hot springs, deep oceans, or very acidic places.

Why are viruses usually not placed in the domains of life?

Most scientists do not consider viruses alive because they do not meet the properties of life on their own.

What is the classification hierarchy from broadest to most specific?

Domain, kingdom, phylum, class, order, family, genus, species.

What mnemonic can help remember the classification hierarchy?

Drunk King Philip Came Over For Good Soup.

What is the broadest level of biological classification?

Domain.

What is the most specific level of biological classification?

Species.

What does it usually mean for organisms to be in the same species?

They can reproduce and produce fertile offspring.

Why is a mule an example related to species definitions?

A mule can be produced by two different animals, but it is usually sterile, so it does not meet the fertile-offspring part of the species definition.

What is science based on?

Inquiry: asking questions and seeking explanations for natural phenomena.

Why does the professor prefer “scientific inquiry” over “scientific method”?

Scientific inquiry is more flexible and allows testing, retesting, and revising explanations rather than following one rigid method.

What are the three main parts of scientific inquiry?

Making observations, forming testable hypotheses, and testing the hypothesis.

What is data?

Recorded observations collected during scientific inquiry.

What is quantitative data?

Numerical data or measurements.

What is qualitative data?

Descriptive data, such as observations of whether something is present or what something looks like.

What type of data is “82 degrees outside”?

Quantitative data.

What type of data is “the TV turned on” or “the TV did not turn on”?

Qualitative data.

What is a hypothesis?

A logical, testable explanation based on observations.

What makes a good hypothesis scientific?

It must be testable using evidence or observations.

Can a hypothesis be rejected?

Yes. A rejected hypothesis is normal in science and can lead to a new hypothesis.

Can a hypothesis be proven true?

No. Evidence can support a hypothesis, but it does not prove it permanently true.

What is a prediction?

What scientists expect will happen if a hypothesis is correct.

How is a prediction different from a hypothesis?

A hypothesis is the explanation; a prediction is the expected outcome if that explanation is correct.

In the TV remote example, what is the hypothesis?

The batteries in the remote are dead.

In the TV remote example, what is the prediction?

If the batteries are replaced, the remote will turn on the TV.

What is an experiment?

A test used to collect data and evaluate a hypothesis.

What is an independent variable?

The variable the researcher changes or manipulates.

What is a dependent variable?

The variable being measured; it depends on the independent variable.

What are controlled variables?

Factors kept the same across groups so the experiment is fair.

What is an experimental group?

The group that receives the condition being tested.

What is a control group?

The group that does not receive the condition being tested.

In the plant watering experiment, what is the independent variable?

Whether the pot is watered.

In the plant watering experiment, what is the dependent variable?

The number of seeds that sprout.

In the plant watering experiment, what are examples of controlled variables?

Same pot type, number of seeds, soil type, amount of soil, fertilizer, sunlight, and humidity.

Why can’t all hypotheses be tested with controlled experiments?

Some variables cannot be controlled, and some tests would be unethical.

Why would an Ebola infection experiment on people be unethical?

It would be unethical to deliberately infect people just to study the disease.

How can scientists test hypotheses when controlled experiments are not possible?

They can make predictions and collect additional observations or existing data.

What was the original giraffe long-neck hypothesis discussed in lecture?

Giraffes evolved long necks because they could reach food other animals could not.

What observation challenged the giraffe feeding hypothesis?

Giraffes often feed at heights that other animals can also reach.

What should scientists do when data do not support a hypothesis?

Reject the hypothesis and form a new one based on additional observations.

What new giraffe hypothesis was discussed?

Male giraffes with longer necks may win fights more often and gain more mating opportunities.

What is a scientific theory?

A broad explanation supported by a large body of evidence and many related hypotheses.

How is a theory different from a hypothesis?

A theory is broader and supported by much more evidence; a hypothesis is narrower and testable.

Can scientific theories change?

Yes. Theories can be revised as new evidence is discovered.

What types of questions cannot be answered by science?

Questions that cannot be tested with evidence, such as supernatural or religious explanations.

Why are supernatural explanations not scientific hypotheses?

They cannot be tested or refuted using scientific evidence.

What did the professor say about data interpretation and mini case studies?

They are for extra practice or interest and will not be assessed in lecture exams.

What should you remember about homework questions not covered in lecture?

If the lecture did not cover it, the professor said it is generally not something he will ask about on the exam.