Biology Chapter 1: Theme in the Study of Life

Systems Biology

Analyzes a living system by looking at multiple components of the system.

Structure

How something is made or what it contains.

Function

What something does.

Cell

Basic unit of life; smallest unit of organization that performs all activities required for life.

Genes

Units of inheritance.

Gene Expression

The process where DNA is used to produce proteins.

Amino acids

Building blocks that make up proteins.

Genomics

The study of sets of genes in one or more species.

Proteomics

The study of all proteins.

Energy Flow in Ecosystem

Energy enters as light from the Sun and exits as heat.

Matter Recycling

Matter cannot be created or destroyed; it is recycled.

What are the levels of biological organization from simplest to most complex?

Molecule → Organelle → Cell → Tissue → Organ → Organism → Population → Community → Ecosystem → Biosphere

What are the two major dynamic processes of an ecosystem?

Energy flow and chemical cycling.

What is the difference between prokaryotic and eukaryotic cells?

Prokaryotic cells have no nucleus or membrane-enclosed organelles; eukaryotic cells have a nucleus and membrane-enclosed organelles.

Which organisms are prokaryotic?

Bacteria and Archaea.

What is DNA's basic function?

DNA stores genetic information.

What are genes?

Units of inheritance that contain information for building molecules in cells.

What is the basic structure of DNA?

A double helix made of two long chains containing four nucleotides: A, G, C, and T.

What is RNA's role in gene expression?

RNA helps transfer DNA's information so a protein can be made.

What is gene expression?

Converting information in a gene into a cellular product.

What is the basic sequence of gene expression?

DNA → RNA → protein

What are emergent properties?

Properties that result from the arrangement and interaction of parts within a system.

What causes emergent properties?

Parts + their arrangement + their interactions.

What is reductionism?

Studying isolated components of a living system.

What is systems biology?

Studying the interactions among parts of a biological system.

Why are regulatory mechanisms important?

They help keep the body’s processes balanced and working properly.

What is feedback regulation?

When the output/product of a process regulates that same process.

What is negative feedback?

A response that reduces the initial stimulus.

What is positive feedback?

A response that speeds up the production of the end product.

What type of feedback is most common?

Negative feedback.

What is an example of negative feedback?

High blood glucose → insulin released → cells take up glucose → blood glucose decreases → less insulin is stimulated.

What are the three domains of life?

Bacteria, Archaea, and Eukarya.

Which domain contains plants, fungi, animals, and protists?

Eukarya.

What are the three kingdoms of multicellular eukaryotic life?

Plants, Fungi, and Animals.

What is the main idea of the unity of life?

Living organisms share similarities because of common ancestry.

What are Darwin's two main ideas?

• Life changes over time.

• Natural selection causes these changes.

What are Darwin's two main ideas?

Descent with modification from common ancestors and natural selection as the mechanism behind it.

What was one of Darwin's observations about individuals?

Individuals vary in their traits, and many of those traits are heritable.

What did Darwin observe about offspring?

More offspring are produced than can survive, causing competition.

What did Darwin infer about individuals with advantageous (helpful) traits?

They are more likely to survive and reproduce.

What happens to advantageous (helpful) traits over generations?

They become more common in the population.

What is natural selection?

he process where individuals with traits that better suit their environment are more likely to survive and reproduce, causing those traits to become more common.

What does natural selection result in?

Adaptation.

What does an evolutionary/tree diagram show?

The evolutionary relationships between ancestors and descendants.

What does a common ancestor tell us?

Organisms sharing a common ancestor are evolutionarily related.

If two organisms share a more recent common ancestor, what does that mean?

They are more closely related.

Discovery

observe + describe

Hypothesis

explain → predict → test

What is qualitative data?

Descriptive data.

What is quantitative data?

Numerical/measured data.

What is inductive reasoning?

Specific observations → general conclusion.

What is deductive reasoning?

General idea → specific prediction.

What is a hypothesis?

An explanation based on observations that leads to a testable prediction.

Can a hypothesis ever be proven completely true?

No. Testing can increase confidence, but it cannot permanently prove a hypothesis true.

What is a controlled experiment?

A scientific test conducted under controlled conditions.

Why do scientists use controlled experiments?

To test a hypothesis while controlling conditions and comparing results.

What is the independent variable?

What the researcher changes/manipulates.

What is the dependent variable?

What the researcher measures.

What is a scientific theory?

A broad explanation supported by a large body of evidence that leads to new testable hypotheses.

Theory

broad explanation + lots of evidence