Science Semester 1

Unit 0

• Independent Variable: The variable that is changed or controlled in a scientific experiment to test its effects on the dependent variable.

• Dependent Variable: The variable that is measured or tested in an experiment.

• Control: A standard of comparison in an experiment that helps to isolate the effects of the independent variable.

• Investigation Plan:

  • Key parts include the hypothesis, materials, procedure, and data analysis methods.

• Data Analysis:

  • Necessary components include collecting data, identifying patterns, and summarizing findings.

  • Graphing Key Parts:

    • X-axis: Independent variable

    • Y-axis: Dependent variable

    • It's better to graph averages to get a clearer understanding of trends.

• Writing Explanations:

  • Key parts: claim, evidence, and reasoning. Each part must include relevant details and connections to the data.

Unit 1

• Carrying Capacity: The maximum population size that an environment can sustain, typically represented by an S-shaped curve on a graph.

• Niche Partitioning: The process by which competing species use the environment differently to coexist.

• Key Terms:

  • Natural Selection: The process where organisms better adapted to their environment tend to survive and produce more offspring.

  • Non-random Mating: Mating based on specific traits, leading to a change in allele frequencies.

  • Evolution: Change in the heritable characteristics of a population over generations.

  • Biodiversity: The variety of life in a particular ecosystem.

  • Geographic Isolation: Separation of populations by geographical barriers leading to speciation.

  • Fossils: Remains of organisms that provide evidence of past life and evolutionary changes.

  • Vestigial Structures: Body parts that have lost their original function (e.g., human appendix).

  • Speciation: The formation of new and distinct species in the course of evolution.

  • Analogous Structures: Structures that serve the same function but differ in structure (e.g., wings of insects vs. birds).

  • Homologous Structures: Structures that are similar due to shared ancestry (e.g., forelimbs of mammals).

• Importance of Fossils: They provide insight into evolutionary history and past environments.

• Natural Selection vs. Evolution: Natural selection is one mechanism by which evolution occurs.

• Conditions for Natural Selection: Variation in traits, inheritance, high rate of population growth, and differential survival and reproduction.

• Formation of New Species: Occurs through reproductive isolation and genetic divergence.

• Plant Seed Coat Scenario: Favorable traits (hard seed coats) would increase in frequency in the population over time.

• Fitness in Evolution: Refers to reproductive success; organisms that are more fit have traits that enhance survival and reproduction.

• Adaptations and Fitness: Traits that enhance survival opportunities in specific habitats increase an organism's fitness.

• Mass Extinctions: Significant biodiversity loss often caused by environmental changes, leading to ecological shifts.

• Natural Selection and Characteristics: Shapes populations by favoring advantageous traits.

• Niche Importance: Represents the role of an organism in its environment and its interaction with biotic and abiotic factors.

• Bacteria Locations: Found in diverse environments including soil, water, and inside organisms.

• Bacterial Growth Factors: Nutrient availability, temperature, pH, and presence of antibiotics.

• Antibiotics: Medications used to fight bacterial infections by disrupting critical bacterial processes.

• Antibiotic Resistance: Occurs when bacteria evolve to survive antibiotic treatment, often due to overuse or misuse of antibiotics.

• Bacteria and Human Health: Not all bacteria are harmful; many play crucial roles in processes like digestion and nutrient cycling.

Unit 2 (Through Lesson 10)

• Cell Cycle Stages:

  • G1: Cell growth.

  • S: DNA synthesis/replication.

  • G2: Further growth and preparation for division.

  • M: Mitosis – division of the nucleus.

  • Cytokinesis: Division of the cytoplasm, resulting in two daughter cells.

• Purpose of Mitosis: To ensure equal distribution of genetic material to daughter cells.

• DNA Structure: Double helix formed by nucleotides (adenine, thymine, cytosine, and guanine).

• Replication Process: DNA unwinds and separates, serving as a template for new strands.

• Cellular Repair Process: After a cut, cells undergo mitosis to replace damaged cells, involving DNA replication for new cell creation.

• End Result of Mitosis: Two genetically identical daughter cells.

• Mutation Occurrence: Errors during DNA replication or exposure to mutagenic agents.

• Types of Point Mutations: Substitution, insertion, and deletion mutations.

• Mutation Effects on DNA: Can lead to changes in protein synthesis and function.

• Purpose of Meiosis: Produce gametes with half the genetic material (haploid).

• Genetic Information after Meiosis: Each gamete contains half of the chromosome number of the original cell (haploid).

• Genetic Variation Locations: Occurs during crossing over, independent assortment, and random fertilization.

• Evolutionary Advantage of Variation: Increases adaptability and survival potential of populations.

• Fertilization: The union of sperm and egg, resulting in the formation of a zygote with a full set of chromosomes.

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