AP® Biology

Flashcards

312 cards with the terms and ideas you need to know cold. The ones you find hard come back sooner.

Multiple choice practice

229 exam-style questions, timed like the real exam, with every answer explained.

Chemistry of Life

7 topics · 43 videos

• Water's polarity explains most of its life-supporting properties
• A few elements, mainly carbon, hydrogen and oxygen, build nearly all biological molecules
• Cells build polymers by removing water and break them apart by adding it back
• A molecule's structure determines its function
• DNA and RNA store information in the order of their nucleotides

Cells

10 topics · 59 videos

• Each organelle's structure fits its job
• Surface area-to-volume ratio limits how big a cell can get
• The membrane's hydrophobic core makes it selectively permeable
• Passive transport follows a gradient; active transport needs energy
• Mitochondria and chloroplasts likely began as free-living prokaryotes

Cellular Energetics

5 topics · 32 videos

• Enzymes lower activation energy, and their shape decides what they can do
• Temperature, pH and inhibitors change how fast enzymes work
• Life stays organized only with a constant input of energy
• Photosynthesis stores light energy in sugar; respiration releases it as ATP
• Electron transport builds a proton gradient that ATP synthase uses to make ATP

Cell Communication and Cell Cycle

6 topics · 36 videos

• Cells communicate by direct contact, local signals or long-distance hormones
• Signal transduction turns a message at a receptor into a response inside the cell
• A change at any step of a pathway can change the cell's response
• Negative feedback restores balance; positive feedback amplifies change
• Checkpoints, cyclins and CDKs keep the cell cycle in check

Heredity

5 topics · 30 videos

• Meiosis halves the chromosome number and shuffles genes
• Crossing over, independent assortment and fertilization create variation
• Probability rules predict the results of genetic crosses
• Many traits break Mendel's simple ratios
• The environment can change how genes show up

Gene Expression and Regulation

8 topics · 49 videos

• Base pairing lets DNA be copied accurately
• Information flows from DNA to RNA to protein
• Cells control which genes are on and how much
• Different gene expression makes different cell types
• Mutations create the variation selection acts on

Natural Selection

12 topics · 69 videos

• Selection acts on individuals, but populations evolve
• Random events like genetic drift also change allele frequencies
• Hardy–Weinberg is the model for a population that isn't evolving
• Fossils, anatomy and DNA all point to common ancestry
• Reproductive isolation leads to new species

Ecology

7 topics · 45 videos

• Energy moves one way through ecosystems, but matter is recycled
• Populations grow until resources limit them
• Species interactions shape communities
• More biodiversity makes ecosystems more resilient
• Human activity speeds up ecosystem change