bio final

Asexual reproduction

produces genetically identical offspring

sexual reproduction

Creates genetically unique offspring

What are advantages of asexual reproduction?

Faster, requires no mate, energy-efficient.

What are disadvantages of asexual reproduction?

No genetic variation; less adaptability to environmental changes.

What are advantages of sexual reproduction?

Genetic diversity, adaptability to environment.

What are disadvantages of sexual reproduction?

Slower, requires more energy, needs a mate.

How do prokaryotes reproduce asexually?

Binary fission.

How do protists reproduce asexually?

Binary fission, budding, or multiple fission.

How do plants reproduce asexually?

Vegetative propagation, budding, fragmentation.

How do animals reproduce asexually?

Budding, fragmentation, parthenogenesis.

What are the key steps in sexual reproduction?

Gamete production, fertilization, embryo development.

How do protists reproduce sexually?

Conjugation or gamete fusion.

How do plants reproduce sexually?

Pollination → fertilization → seed and embryo development.

How do animals reproduce sexually?

Internal or external fertilization → embryo development.

Name the phases of meiosis I.

Prophase I, Metaphase I, Anaphase I, Telophase I.

What happens in Prophase I?

Chromosomes condense, homologs pair, crossing over occurs.

What happens in Metaphase I?

Homologous chromosomes align at the equator.

What happens in Anaphase I?

Homologs separate.

What happens in Telophase I?

Two haploid cells form.

Name the phases of meiosis II.

Prophase II, Metaphase II, Anaphase II, Telophase II.

What happens in Anaphase II?

Sister chromatids separate.

What is the ploidy at the end of meiosis I and II?

Meiosis I: haploid; Meiosis II: haploid.

When do homologs and sister chromatids separate?

Homologs: Anaphase I; Chromatids: Anaphase II.

What is crossing over and when does it occur?

Exchange of genetic material between homologs in Prophase I.

What are the products of meiosis?

Four haploid cells with genetically unique chromosomes.

Define gene, locus, allele.

Gene: a unit of heredity. Locus: location on chromosome. Allele: variant of a gene.

How many alleles can a diploid organism have per gene?

Two.

Why can a population have more alleles than an individual?

Multiple alleles can exist in a population, but individuals only inherit two.

How do you determine inheritance mode from a pedigree?

Track presence across generations and genders; recessive traits skip generations, sex-linked traits affect males more often.

What is a Punnett square used for?

Predicting genotypes and phenotypes of offspring.

What is complementary base pairing?

A pairs with T (or U in RNA), C pairs with G.

What direction are DNA strands arranged?

Antiparallel (5' to 3' vs 3' to 5').

What is the process of DNA replication?

Unwinding DNA → leading strand continuous synthesis → lagging strand Okazaki fragments.

What enzymes are used in DNA replication?

Helicase, DNA polymerase, ligase, primase.

How many bases are in a codon?

Three.

Where does translation begin on mRNA?

5’ end.

What is transcription?

Making mRNA from DNA using RNA polymerase.

What is translation?

Making proteins from mRNA using ribosomes.

How do transcription factors regulate gene expression?

By binding to DNA at promoter/enhancer regions.

Why are transcription factors important for specialized cell function?

They activate specific genes based on cell type.

What two conditions are required for natural selection?

Heritable variation and differential reproductive success.

How does natural selection change allele frequencies?

Favors beneficial traits, increasing their frequency in the population.

What is adaptive evolution?

Evolution via natural selection leading to improved fitness.

What is random evolution?

Evolution due to chance (e.g., genetic drift).

Name two types of random evolution.

Genetic drift, mutation.

What is genetic drift?

Random change in allele frequencies, especially in small populations.

What is the founder effect?

A few individuals start a new population with reduced genetic diversity.

What is the bottleneck effect?

A sudden population reduction decreases genetic diversity.

Define: stabilizing, directional, disruptive selection.

Stabilizing: favors average. Directional: favors one extreme. Disruptive: favors both extremes.

What does a phylogenetic tree show?

Evolutionary relationships and common ancestors.

What are patterns of dispersion?

Clumped, uniform, random.

What is the equation for exponential growth?

∆N/∆T = rN

What happens when resources are unlimited?

Population grows exponentially.

What is the logistic growth equation?

∆N/∆T = rN(K−N)/K

What limits logistic growth?

Carrying capacity (K).

What is density-dependent regulation?

Factors like competition and disease increase with population density.

What is density-independent regulation?

Factors like natural disasters affect population regardless of density.

Name two diversity metrics.

Species richness, Shannon index.

How is the Shannon index used?

To compare diversity across communities.

What regulates community structure?

Abiotic (nutrients) and biotic (predation) factors.

What is the First Law of Thermodynamics?

Energy is conserved—it cannot be created or destroyed.

What is a productivity pyramid?

A diagram showing energy flow between trophic levels.