Primary Deck

What are photoautotrophs and where are they found?

Organisms that use light to make food from CO₂; found in Plantae, Protista (algae), and some Bacteria.

What is chlorophyll and what light does it absorb/reflect?

Chlorophyll absorbs blue and red light, reflects green; blue/red are best for photosynthesis.

What is the equation for photosynthesis and where does it occur?

6CO₂ + 6H₂O + light → C₆H₁₂O₆ + 6O₂; occurs in chloroplasts.

Is photosynthesis endergonic or exergonic?

Endergonic; uses energy from sunlight.

What are the two stages of photosynthesis?

Light reactions (thylakoid) and Calvin cycle (stroma).

What are the inputs/outputs of light reactions?

Light + H₂O → ATP, NADPH, O₂.

What are the inputs/outputs of the Calvin cycle?

CO₂ + ATP + NADPH → G3P (sugar).

What is chemiosmosis in photosynthesis?

Proton gradient drives ATP synthase to make ATP.

How do plants use sugars and how do heterotrophs use them?

Plants use for energy/storage; heterotrophs eat them.

Why do cells divide?

Unicellular: reproduction; multicellular: growth and repair.

What must happen before cell division?

DNA must be duplicated.

What is the cell cycle?

Interphase (~90%) + mitotic phase (~10%).

What happens in interphase?

Growth, DNA replication, preparation.

What happens in mitosis?

Nuclear division into two identical cells.

What are the stages of mitosis?

Prophase, Prometaphase, Metaphase, Anaphase, Telophase.

What is binary fission?

Prokaryotic cell division.

What is the difference between chromosome and chromatin?

Chromosome = condensed DNA; chromatin = loose DNA.

What are sister chromatids?

Identical copies of a chromosome.

What is a centromere?

Holds sister chromatids together.

What is the difference between diploid and haploid?

Diploid = 2 sets; haploid = 1 set.

What are homologous chromosomes?

Pairs with same genes, one from each parent.

What goes into and results from meiosis?

1 diploid cell → 4 haploid gametes.

What is meiosis and its end result?

Cell division for gametes; produces genetic variation and halves chromosome number.

What are the two stages of meiosis?

Meiosis I (homologous separate), Meiosis II (sister chromatids separate).

What is the law of independent assortment?

Random distribution of chromosomes → diversity.

What causes Down syndrome?

Nondisjunction → trisomy 21.

What determines sex in humans?

Sperm (X or Y chromosome).

What are Turner and Klinefelter syndromes?

Turner = XO; Klinefelter = XXY.

What is an allele?

Version of a gene.

What is the difference between genotype and phenotype?

Genotype = genes; phenotype = traits.

What is the difference between homozygous and heterozygous?

Same vs different alleles.

What is the difference between dominant and recessive traits?

Dominant expressed; recessive masked.

What is a carrier?

Heterozygous for a recessive trait.

Who was Mendel?

Father of genetics; discovered inheritance laws.

What is the law of segregation?

Alleles separate during gamete formation.

What is independent assortment?

Different genes assort independently.

Why are dominant lethal alleles rare?

They kill before reproduction.

What are sex-linked traits?

Traits on X chromosome (ex: hemophilia).

Why are sex-linked traits more common in males?

Males have only one X chromosome.

What is a codon?

3-base sequence coding for an amino acid.

What is DNA replication?

Copying DNA before division.

What is transcription?

DNA → RNA.

What is translation?

RNA → protein.

What are the types of mutations?

Substitution, insertion, deletion.

What are the three parts of a nucleotide?

Phosphate, sugar, base.

What is the difference between DNA and RNA?

DNA double/T; RNA single/U.

What is the structure of DNA?

Double helix with hydrogen bonds.

What is base pairing?

A-T, C-G; RNA uses U instead of T.

How does DNA replication work?

Helicase unwinds; polymerase builds new strands using base pairing.

What is the purpose of mRNA?

Carries DNA code to ribosome.

How do ribosomes read codons?

Match with tRNA anticodons → correct amino acid.

What is a polypeptide chain?

Amino acids linked by peptide bonds.

When do mutations occur?

During replication or from environmental damage.

Which mutations are most harmful?

Insertions/deletions (frameshift).

What is a virus?

Non-living particle requiring host to reproduce.

What are the main properties of a virus?

Genetic material + protein coat; no independent metabolism.

How does cancer start?

Mutations in cell cycle genes → uncontrolled division.

What is evolution?

Change in populations over time.

What is the difference between microevolution and macroevolution?

Small vs large-scale changes.

Who was Darwin?

Proposed natural selection; wrote Origin of Species (1859).

What are the two components of Darwin's theory?

Variation + natural selection.

What is natural selection?

Individuals with favorable traits survive/reproduce more.

Is natural selection goal-oriented?

No.

What is evidence for evolution?

Fossils, anatomy, DNA, embryology.

What is genetic drift?

Random change in allele frequency.

What is gene flow?

Movement of genes between populations.

What are the four causes of evolution?

Mutation, gene flow, genetic drift, natural selection.

What is the bottleneck effect?

Population reduced → less diversity.

What is the founder effect?

New population from small group.

What are the sources of variation?

Mutation and recombination; mutation is the ultimate source.

What is a species?

Group that can interbreed.

What is the difference between prezygotic and postzygotic barriers?

Before vs after fertilization.

What is speciation?

Formation of new species.

What is allopatric speciation?

Geographic isolation.

What is sympatric speciation?

Same location speciation.

How does allopatric speciation occur?

Isolation → divergence → new species.

What is a phylogenetic tree?

Shows evolutionary relationships.

What is cladistics?

Groups by shared traits.

What is taxonomy?

Classification system.

What is the binomial naming format?

Genus species (italicized).

Why are scientific names used?

Universal naming system.

What is the hierarchy order in taxonomy?

Domain → Kingdom → Phylum → Class → Order → Family → Genus → Species.

What is the difference between gymnosperms and angiosperms?

Naked seeds vs flowering plants.

What is adaptive radiation?

Rapid diversification into new niches.

What was the Cambrian Explosion?

Rapid evolution ~541 million years ago.

What is the difference between diploblastic and triploblastic?

2 vs 3 germ layers.

What is the difference between radial and bilateral symmetry?

Multiple planes vs one plane.

What is the difference between protostome and deuterostome?

Different developmental pathways.

How are phyla related?

Based on evolutionary traits and body plans.