biology

• Cellular Respiration: Process by which cells convert glucose and oxygen into energy, producing carbon dioxide and water as byproducts.

Scientific Method & Inquiry

Observations → Questions → Hypotheses → Predictions → Experiments → Interpretation → Conclusion
(From the slide: “Observe, Ask, Hypothesize, Predict, Experiment, Interpret, Draw conclusion.” )

Hypothesis

A tentative explanation that can be tested.
(From the slide: “A tentative explanation for an observation that leads to predictions for experiments.” )

Theory

A broad explanation supported by a large body of evidence.
(From the slide: “General explanations of natural phenomena supported by a large body of experiments and observations.” )

Clicker Question: What is a hypothesis?

Correct answer: B. a tentative explanation that can be tested by experiments

🌎 What Is Life?

Living organisms:

• Are complex and organized

• Respond to the environment

• Reproduce

• Evolve genetically over time
  (From the slide: “Living organisms are complex… able to change… able to reproduce… have the capacity to evolve.” )

Living vs. Nonliving

Both obey physics and chemistry.
Correct clicker answer: A. They both conform to the basic laws of chemistry and physics.

🔥 Thermodynamics & Life

First Law

Energy is neither created nor destroyed.

Second Law

Entropy (disorder) increases in a closed system.

Clicker Question: Where is entropy definitely increasing?

Correct answer: C. melting ice in a glass of soda

🧬 Spontaneous Generation vs. Biogenesis

Francesco Redi tested whether life arises from nonliving matter.

Hypothesis:

Living matter only arises from other living matter.

Prediction:

Meat isolated from flies will not produce maggots.
(From the slide: “Non-living matter (rotten meat) when isolated from living matter will not generate life.” )

Experiment:

• Jar with gauze (flies blocked)

• Jar without gauze (flies enter)
  Only difference = presence of flies (independent variable).
  Dependent variable = maggots.

Conclusion:

Maggots only appeared where flies had access → supports biogenesis.

🧫 Cells & Their Features

All organisms are made of one or many cells.

Three Key Features of Cells

• Membranes regulate internal environment (homeostasis)

• Information storage & transmission (DNA → RNA → protein)

• Energy acquisition & use (metabolism)
  (From the slide: “A mechanism to separate… store and transmit information… acquire, transform, and use energy.” )

Cell Membrane

Controls communication with the environment; eukaryotes have membrane-bound organelles.

Nucleic Acids

DNA stores and transmits information; base pairing ensures accurate replication.

Central Dogma

DNA → RNA → Protein
(From the slide: “DNA is transcribed into an RNA message… translated into a protein.” )

Energy & Metabolism

Organisms harness energy from:

• The sun

• Chemical compounds

Metabolism = reactions that convert energy or build/break molecules.

📘 Quick Study Flashcards

Each item is a Guided Link so you can expand any topic instantly.

• Hypothesis — tentative, testable explanation

• Theory — broad, evidence-supported explanation

• Characteristics of Life — complexity, response, reproduction, evolution

• First Law — energy conservation

• Second Law — entropy increases

• Biogenesis — life comes from life

• Cell Membrane — regulates internal environment

• Central Dogma — DNA → RNA → protein

• Metabolism — energy conversion processes