Science Semester 1

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.

X-axis

Represents the independent variable in a graph.

Y-axis

Represents the dependent variable in a graph.

Claim

Part of writing explanations that states the main argument or conclusion.

Evidence

Part of writing explanations that provides data or facts to support a claim.

Reasoning

Part of writing explanations that connects the evidence to the claim.

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.

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).

Fitness in Evolution

Refers to reproductive success; organisms that are more fit have traits that enhance survival and reproduction.

Mass Extinctions

Significant biodiversity loss often caused by environmental changes, leading to ecological shifts.

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.

Cell Cycle Stages

Include G1 (cell growth), S (DNA synthesis), G2 (preparation for division), M (mitosis), and cytokinesis.

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).

Mutation Occurrence

Errors during DNA replication or exposure to mutagenic agents.

Purpose of Meiosis

To produce gametes with half the genetic material (haploid) for sexual reproduction.

Fertilization

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