BIO 1070 Exam 1 Study Guide: Foundations of Biology, Cell Division, and Mendelian Genetics

Chapter 1: Evolution, the Themes of Biology, and Scientific Inquiry

Properties of Life

• Order: Living things exhibit complex but ordered organization.

• Regulation (Homeostasis): Organisms maintain a stable internal environment.

• Growth and Development: Organisms grow and develop according to specific instructions coded in their DNA.

• Energy Processing: Living things acquire and use energy for maintenance and growth.

• Response to the Environment: Organisms respond to environmental stimuli.

• Reproduction: Organisms reproduce their own kind.

• Evolutionary Adaptation: Populations evolve over generations through the process of natural selection.

Levels of Life

• Biosphere > Ecosystem > Community > Population > Organism > Organ System > Organ > Tissue > Cell > Organelle > Molecule > Atom

• Cell: The basic unit of life; all living things are composed of cells.

DNA and Its Importance

• DNA (Deoxyribonucleic Acid): The molecule that stores genetic information in all living organisms.

• DNA encodes instructions for building and maintaining an organism.

Energy Use in Living Things

• Photosynthesis: The process by which producers (e.g., plants) convert solar energy into chemical energy.

• Cellular Respiration: The process by which cells break down glucose to release energy for cellular work.

Unity and Diversity of Life

• Unity: All living things share common features such as DNA, cellular structure, and metabolic pathways.

• Diversity: Life is diverse due to evolutionary adaptations to different environments.

The Three Domains of Life

• Bacteria: Prokaryotic, unicellular organisms.

• Archaea: Prokaryotic, often found in extreme environments.

• Eukarya: Eukaryotic organisms, including protists, fungi, plants, and animals.

Science and Scientific Inquiry

• Science: A way of knowing about the natural world based on evidence and logic.

• Basis of Science: Observation, experimentation, and reasoning.

Observational vs. Experimental Science

• Observational Science: Gathering data through observation without manipulation.

• Experimental Science: Testing hypotheses through controlled experiments.

Scientific Method Outline

1. Observation

2. Question

3. Hypothesis (a statement believed to be true)

4. Prediction ("If...then" statement)

5. Experiment

6. Results/Analysis

7. Conclusion

Key Vocabulary

• Biology: The scientific study of life.

• Producers: Organisms that make their own food (e.g., plants).

• Consumers: Organisms that obtain energy by eating other organisms.

• Eukaryote: Organism with cells that contain a nucleus.

• Prokaryote: Organism with cells lacking a nucleus.

• Photosynthesis: Process by which plants convert light energy to chemical energy.

• Cellular Respiration: Process of breaking down glucose for energy.

• Ecology: Study of interactions between organisms and their environment.

• Evolution: Change in populations over time.

• Data: Recorded observations; can be qualitative or quantitative.

• Qualitative Data: Descriptive, non-numerical data.

• Quantitative Data: Numerical measurements.

• Hypothesis: A proposed explanation for an observation.

• Controlled Experiment: An experiment in which only one variable is changed.

• Theory: A broad explanation supported by a large body of evidence.

• Inductive Reasoning: Deriving general principles from specific observations.

• Deductive Reasoning: Predicting specific results from general principles.

Additional info: A hypothesis is not an "If...then" statement; that is a prediction. The experiment tests the prediction, which is based on the hypothesis.

Chapter 12: The Cell Cycle & Mitosis

Purpose of Cell Division

• Growth, repair, and reproduction in organisms.

• Ensures genetic continuity between generations of cells.

Mitosis

• Mitosis: Division of the nucleus resulting in two genetically identical daughter cells.

• Result: Two diploid cells, each with the same number of chromosomes as the parent cell.

Meiosis

• Meiosis: Cell division that reduces chromosome number by half, producing four genetically unique gametes.

• Result: Four haploid cells (gametes) with half the chromosome number of the original cell.

Chromosome Numbers in Humans

• Somatic Cells: 46 chromosomes (diploid, 2n).

• Gametes: 23 chromosomes (haploid, n).

Parts of the Cell Cycle

• Interphase: Cell grows, performs normal functions, and duplicates DNA; most of the cell's life is spent here.

• Mitotic (M) Phase: Includes mitosis and cytokinesis; cell divides.

Events During Interphase

• G1: Cell growth

• S: DNA replication

• G2: Preparation for mitosis

Events During Mitotic Phase

• Mitosis: Division of the nucleus (prophase, metaphase, anaphase, telophase)

• Cytokinesis: Division of the cytoplasm

Cytokinesis in Animals vs. Plants

• Animals: Formation of a cleavage furrow that pinches the cell in two.

• Plants: Formation of a cell plate that develops into a new cell wall.

Cell Division in Cancer Cells

• Cancer cells divide uncontrollably due to loss of cell cycle regulation.

• May form tumors (benign or malignant) and can metastasize (spread to other tissues).

Key Vocabulary

• Daughter Cell: Cell produced by division of a parent cell.

• Sister Chromatids: Identical copies of a chromosome connected by a centromere.

• Centromere: Region where sister chromatids are joined.

• Mitotic Spindle: Structure made of microtubules that separates chromosomes.

• Kinetochore: Protein structure on chromatids where spindle fibers attach.

• Metaphase Plate: Imaginary plane where chromosomes align during metaphase.

• Cleavage Furrow: Indentation that begins cytokinesis in animal cells.

• Cell Plate: Structure that forms during cytokinesis in plant cells.

• Benign: Non-cancerous tumor.

• Metastasize: Spread of cancer cells to new areas.

Chapter 13: Meiosis & Sexual Life Cycles

Asexual vs. Sexual Reproduction

• Asexual Reproduction: Offspring arise from a single parent; genetically identical to parent.

• Sexual Reproduction: Offspring arise from fusion of gametes; genetically unique.

Chromosome Numbers in Humans

• Somatic Cells: 46 chromosomes (23 pairs).

• Gametes: 23 chromosomes.

• Chromosomes are in pairs because one set is inherited from each parent.

Meiosis I and II

• Meiosis I: Homologous chromosomes separate, reducing chromosome number by half.

• Meiosis II: Sister chromatids separate, similar to mitosis.

Crossing Over

• Exchange of genetic material between homologous chromosomes during prophase I of meiosis.

• Increases genetic diversity.

Comparison: Mitosis vs. Meiosis

• Similarities: Both involve DNA replication, chromosome alignment, and separation.

• Differences: Mitosis produces two identical cells; meiosis produces four unique gametes with half the chromosome number.

Factors Increasing Genetic Variability

1. Independent assortment of chromosomes during meiosis.

2. Crossing over during meiosis I.

3. Random fertilization of gametes.

Key Vocabulary

• Heredity: Transmission of traits from parents to offspring.

• Gene: Unit of heredity; segment of DNA coding for a trait.

• Homologous Chromosomes: Chromosome pairs with genes for the same traits.

• Autosomes: Non-sex chromosomes.

• Sex Chromosomes: Chromosomes that determine sex (X and Y in humans).

• Meiosis: Cell division producing gametes.

• Diploid (2n): Two sets of chromosomes.

• Haploid (n): One set of chromosomes.

Chapter 14: Mendel and the Gene Idea

Gregor Mendel and His Experiments

• Gregor Mendel: Father of genetics; studied inheritance in pea plants.

• Used pea plants because they have easily observable traits and can self- or cross-pollinate.

P1, F1, and F2 Generations

• P1: Parental generation (true-breeding).

• F1: First filial generation (offspring of P1).

• F2: Second filial generation (offspring of F1 self- or cross-pollination).

Law of Segregation

• Each individual has two alleles for each gene; these alleles separate during gamete formation.

Phenotypic Ratios in F2 Generation

• Mendel found a 3:1 ratio of dominant to recessive phenotypes in the F2 generation for many traits.

Punnett Squares

• Diagram used to predict the genetic outcomes of a cross.

• Shows possible combinations of parental alleles in offspring.

Law of Independent Assortment

• Alleles of different genes assort independently during gamete formation.

Degrees of Dominance

• Complete Dominance: One allele completely masks the other.

• Incomplete Dominance: Heterozygote shows an intermediate phenotype.

• Codominance: Both alleles are fully expressed in the heterozygote.

Environmental Effects on Phenotype

• Phenotype can be influenced by environmental factors (e.g., nutrition, temperature).

Examples of Genetic Disorders

• Recessive Disorders: Cystic fibrosis, sickle cell anemia.

• Dominant Disorders: Huntington's disease.

• Multifactorial Disorders: Heart disease, diabetes (influenced by genes and environment).

Key Vocabulary

• Character: Heritable feature (e.g., flower color).

• Trait: Variant of a character (e.g., purple or white flowers).

• True-breeding: Organisms that produce offspring identical to themselves.

• Hybrid: Offspring of parents with different traits.

• Dominant: Allele that determines phenotype in heterozygote.

• Recessive: Allele masked in heterozygote.

• Alleles: Alternative forms of a gene.

• Homozygous: Two identical alleles for a gene.

• Heterozygous: Two different alleles for a gene.

• Phenotype: Observable traits.

• Genotype: Genetic makeup.

• Pleiotropy: One gene affects multiple traits.

• Epistasis: One gene affects the expression of another gene.

• Polygenic Inheritance: Multiple genes affect a single trait.

• Multifactorial: Traits influenced by genes and environment.

• Pedigree: Family tree showing inheritance of traits.