Biology Essential Outcomes

Evolution by natural selection

The process by which favorable mutations in a population increase in frequency over time due to the survival and reproduction of organisms carrying those mutations.

Recombination

The process of exchanging genetic material between homologous chromosomes during meiosis, resulting in new combinations of alleles.

Descent with modification

The idea that all organisms share a common ancestor and have evolved through gradual changes in their characteristics over time.

Scientific theory

A well-supported and testable explanation of natural phenomena that is based on empirical evidence.

DNA replication

The process by which DNA is copied during the cell cycle, resulting in two identical copies of the DNA molecule.

Mitosis

The process of cell division in which a single cell divides into two identical daughter cells.

Meiosis

The process of cell division in which a diploid cell divides into four genetically different haploid daughter cells.

Homologous chromosomes

Chromosome pairs that carry the same genes in the same locations, one from each parent.

Recombination

The process by which new combinations of alleles are created through the exchange of genetic material between homologous chromosomes during meiosis.

Genetic equilibrium

The state in which allele frequencies in a population remain constant over time, indicating no evolution is occurring.

Selection

The process by which certain traits or alleles become more or less common in a population due to their effects on survival and reproduction.

Heritable variation

The presence of genetic differences among individuals in a population that can be passed on to offspring.

Hardy-Weinberg equilibrium

The state in which allele frequencies in a population remain constant from generation to generation, indicating no evolution is occurring.

Dominance

The relationship between alleles in which one allele masks the expression of another allele in the heterozygous condition.

Evolution

The change in allele frequencies in a population over time, resulting in the development of new species and the diversity of life.

Kin selection

The theory that individuals are more likely to help relatives because they share a higher proportion of their genes.

Cooperation

Behavior that benefits others at a cost to oneself, often seen in situations where individuals are closely related or have repeated interactions.

Phylogenetic tree

A diagram that represents the evolutionary relationships among a group of organisms based on shared derived characteristics.

Species concept

A way of defining what constitutes a species, often based on morphological, biological, or phylogenetic criteria.

Virulence

The degree of harm caused by a parasite to its host, often influenced by the trade-off between transmission and host survival.

Ultimate explanation

The role of natural selection, arms races, history, and chance in creating or continuing a trait.

Costs of large brains

Large brains cost 2% of mass and 20% of energy.

Possible advantages of large brains

Utility hypothesis (survival-related skills) favored by natural selection, mating mind hypothesis (mating-related skills) favored by sexual selection.

Deep Learning

Making connections, understanding, and applying knowledge. Excludes memorization.

Serial Dilutions

Calculation of CFU/mL using dilution factor and volume of culture plate. Dilution factor calculated by dividing final volume by sample volume and multiplying by the denominator of serial dilution fractions.

Role of cyclin in the cell cycle

Cyclin regulates the rate of cell division and is important in cell cycle checkpoints.

Microscope calibration

Formula for measuring objects using stage divisions and ocular divisions. Calculation of magnification using ocular lens and objective lens.

Chi squared statistical analysis

Null Hypothesis states no effect/correlation/will be no change. Alternate Hypothesis states there is an effect/correlation/will be a change.

Chi squared analysis

Determines if data is significant enough to support the alternate hypothesis. Compares observed values (collected in the study) with expected values (calculated based on null hypothesis). Calculation:x^2 = sum of ((O-E)^2/E).

Degrees of freedom and critical value

Critical value is compared to chi-square value for statistical significance. Can be found on a chart or provided.

Primary vs secondary scientific articles

Primary articles contain original data and ideas from scientific investigations reported by scientists. Secondary articles review and analyze primary sources in more depth.

FST Population Genetics

FST = 1 - (average heterozygosity expected within populations / heterozygosity expected across total population). HS = (2p1q1 + 2p2q2)/2. HT = 2pTqT. Interpretation of FST values:FST = 0:no disturbance. FST > 0.25:significant disturbance. FST = 1:complete separation of populations.

Allozyme Electrophoresis for genetic variability calculation

Takes advantage of the fact that organisms produce allelic variants of enzymes called allozymes. Genotype at a gene locus coding for an enzyme can be inferred from the number and position of spots observed on gels. Genetic variation in a population is the average frequency of heterozygous individuals per locus. Calculated by determining the frequency of heterozygotes at each locus and averaging these frequencies over all loci.

Creating phylogenetic trees using DNA sequencing

Phylogenies can be estimated by looking at differences in DNA sequence. Species with the most differences is the out-group. If no differences, it is the same species and should be drawn on the same vertical line. Length of horizontal lines may indicate the