Biology 201-Lecture #1

Theme: The study of life can be divided into different levels of biological organization

1. Atoms 2. Molecules and macromolecules 3. Cells 4. Tissues 5. Organs 6. Organism 7. Population 8. Community 9. Ecosystem 10.Biosphere

Theme: There are 7 key features of life

1. Cells and organization 2. Energy use and metabolism 3. Response to environmental change 4. Regulation and homeostasis 5. Growth and development 6. Reproduction 7. Biological evolution

Theme: The Continuity of Life Is Based on Heritable Information in the Form of DNA

Chromosomes contain most of a cell's genetic material in the form of DNA (deoxyribonucleic acid)

Eukaryotic cells vs Prokaryotic cells

Eukaryotes: generally much larger than prokaryotic cells, has a nuclear, contain membrane- bound organelles Prokaryotes: simpler and usually smaller, does not contain a nucleus or other membrane-enclosed organelles

Examples of eukaryotic cells and prokaryotic cells

Eukaryotic: plants, animals, fungi, and all other forms of life Prokaryotic: bacteria and archaea

Theme: Feedback Mechanisms Regulate Biological Systems

Feedback mechanisms allow biological processes to self-regulate

Biologists ask questions such as

How does a single cell develop into an entire complex organism? How does a virus attach to and enter cells? How do living things interact in communities?

Example of a hypothesis

Observation: Your flashlight doesn't work Question: Why doesn't your flashlight work? Hypothesis 1: The batteries are dead Hypothesis 2: The bulb is burnt out

hypothesis-based science

Observations can lead us to ask questions and propose hypothetical explanations called hypotheses

Structure and function are correlated at all levels of biological organization

Seagull as an example of form fitting function

Theme: Cells are an organism's basic units of structure and function

The cell is the lowest level of organization that can perform all activists required for life

Scientists use two main forms of inquiry in their study of nature

The word Science is derived from Latin and means "to know" Inquiry is the search for info and explanation

Hypothesis

a tentative answer to a well-framed question

Genes

a unit of heredity that is transferred from a parent to offspring and is held to determine some characteristic of the offspring.

Discovery science

describes natural structures and processes as accurately as possible through careful observation and analysis of data

There are two main types of scientific inquiry:

discovery science and hypothesis-based science

An organism's _______ is its entire set of genetic instruction

genome

Each link of a chain is one of four kinds of chemical building blocks called

nucleotides

A scientific hypothesis leads to predictions that can be tested by

observational or experimental

Qualitative

or descriptions rather than measurements

Quantitative

or recorded measurements, which are sometimes organized into tables and graphs

Types of Data

qualitative and quantitative

DNA

substance of which genes and chromosomes are made

A hypothesis must be

testable and falsifiable

The ability of cells to divide

the basis of all reproduction, growth, and repair of multicellular organisms

What is biology?

the scientific study of life

Each DNA molecule is made up of

two long chains arranged in a double helix

Theories in science

In the context of science, a theory is Broader in scope than a hypothesis General, and can lead to new testable hypotheses Supported by a large body of evidence in comparison to a hypothesis

All cells:

are enclosed by a membrane and use DNA as their genetic information

Negative feedback

as more of a product accumulates, the process that creates it slows and less of the product is produced

Positive feedback

as more of a product accumulates, the process that creates it speeds up and more of the product is produced