BIO 101 FINAL Cumulative Review

Levels of organization from smallest to largest?

Atom, molecule, cell, tissue, organ, organism, population, ecosystem.

What is homeostasis?

Maintaining a stable internal environment, like a thermostat.

Prescription for scientific method wording?

You can only test one independent variable, hold everything else constant, and always include a null hypothesis.

Bond types: covalent, ionic, hydrogen?

Covalent shares electrons (strong). Ionic transfers electrons (opposite charges attract). Hydrogen bonds are weak but numerous.

Why is water special for life?

Polarity gives cohesion, adhesion, high specific heat and strong solvent ability.

pH scale?

Below 7 acidic, 7 neutral, above 7 basic. Buffers resist pH changes.

Prokaryote vs eukaryote?

Prokaryotes have no membrane-bound nucleus. Eukaryotes do.

Trace a secreted protein.

Ribosome on rough ER, vesicle to Golgi, vesicle to cell membrane, secreted.

Plant cell extras?

Cell wall, chloroplasts and a large central vacuole.

What do enzymes do?

Lower activation energy. They end in -ase, are not used up, and denature when too hot.

What is ATP and how does it release energy?

Adenine, ribose and three phosphates. Hydrolysis removes a phosphate to make ADP and releases energy.

Passive vs active transport?

Passive goes high to low with no energy (diffusion, osmosis). Active goes low to high and costs ATP.

Osmosis in a hypotonic solution?

Water moves in and the cell swells.

Photosynthesis summary?

Light energy plus CO2 and water makes sugar and releases oxygen.

Cellular respiration summary?

Sugar plus oxygen makes ATP, CO2 and water. It is the reverse energy direction of photosynthesis.

Rule of 10 percent?

Only about 10 percent of energy moves to the next level in a food chain.

Evidence mitochondria came from bacteria?

Own circular DNA and ribosomes, endosymbiosis.

Transcription vs translation?

Transcription copies DNA into mRNA in the nucleus. Translation reads mRNA at the ribosome to build a protein.

What is splicing?

Introns are removed and exons joined before mRNA leaves the nucleus. Errors can cause disease.

Why can antibiotics target bacterial ribosomes?

Prokaryotic and eukaryotic ribosomes differ enough that drugs hit bacteria but not human cells.

DNA replication key enzymes?

Helicase unwinds, primase makes primers, DNA polymerase builds, ligase seals Okazaki fragments.

Mitosis vs meiosis?

Mitosis: two identical diploid cells for growth and repair. Meiosis: four different haploid gametes with crossing over and independent assortment.

Bb x Bb cross ratios?

Genotypes 1 BB : 2 Bb : 1 bb, phenotypes 3 dominant to 1 recessive.

Blood type genetics?

IA and IB are codominant and both dominant to i. Type O is ii.

What drives evolution?

Natural selection on heritable variation, plus chance such as genetic drift.

What is speciation?

Populations diverge until they no longer interbreed.

Good final exam strategy per the notes?

Mushy words (most, some, few) are hard to prove. Absolute words (all, none) are usually false. Review chapter intros and practice assessments, not just rereading.