Biology Fundamentals: Cell Structure, Genetics, Evolution, and Biochemistry

Properties of Living Organisms

Characteristics that distinguish living organisms from non-living matter, including growth, reproduction, metabolism, response to stimuli, and homeostasis.

Fundamental Organizing Principle of Biology

Evolution, which explains the diversity of life and the adaptation of organisms to their environments.

Organisms Interaction with Environment

Examples include nutrient cycling, energy flow, and energy conversion processes in ecosystems.

Energy Transfer and Transformation

Processes by which living organisms convert energy from one form to another, such as photosynthesis and cellular respiration.

Structure/Function Correlations

The relationship between the physical structure of biological systems and their functions, such as the shape of enzymes and their catalytic activity.

Cell as Basic Unit of Life

Cells are the smallest units of life that exhibit all the properties of living organisms.

Common Features of All Cells

All cells have a plasma membrane, cytoplasm, ribosomes, and genetic material (DNA).

Prokaryotic vs Eukaryotic Cells

Prokaryotic cells lack a nucleus and membrane-bound organelles, while eukaryotic cells have a nucleus and organelles.

Chromosomes

Structures composed of DNA and protein that carry genetic information; genes are segments of DNA within chromosomes.

Structure and Function of DNA

DNA is a double helix made of nucleotides, which encode the genetic instructions for protein synthesis.

Nucleotides

The building blocks of DNA and RNA, consisting of a sugar, a phosphate group, and a nitrogenous base.

Transcription

The process of synthesizing RNA from a DNA template.

Translation

The process of synthesizing proteins from mRNA by ribosomes.

Positive vs Negative Feedback Mechanisms

Positive feedback amplifies a response, while negative feedback reduces it to maintain homeostasis.

Descent with Modification

The principle that species evolve over time through gradual changes and adaptations.

Classification of Organisms

Organisms are classified into hierarchical categories from Domain to species based on shared characteristics.

Three Domains of Life

The three domains are Bacteria, Archaea, and Eukarya, each containing distinct types of organisms.

Unity of Living Organisms

Characteristics that demonstrate the common ancestry and shared traits among diverse life forms.

Scientific Process

A method of inquiry that involves forming hypotheses, conducting experiments, and analyzing data to draw conclusions.

Qualitative vs Quantitative Data

Qualitative data describes characteristics or qualities, while quantitative data involves numerical measurements.

Scientific Control

A standard for comparison in an experiment that helps isolate the effects of the independent variable.

Dependent, Independent, and Controlled Variables

The dependent variable is measured, the independent variable is manipulated, and controlled variables are kept constant.

Natural Selection

The process by which organisms better adapted to their environment tend to survive and reproduce more successfully.

Darwin's Observations

Key observations include the variation among individuals, the struggle for existence, and the survival of the fittest.

Darwin's Inferences

Inferences include that individuals with advantageous traits are more likely to survive and reproduce, leading to evolutionary change.

Evolutionary Adaptation

Changes in a species over time that enhance its survival and reproduction in a specific environment.

Biological Tree

A diagram representing the evolutionary relationships among various biological species, illustrating common ancestry.

Discovery vs Hypothesis-Based Inquiry

Discovery inquiry involves exploring and observing phenomena, while hypothesis-based inquiry tests specific predictions.

Controlled Experiment

An experiment in which all variables are kept constant except for the one being tested, ensuring reliable results.

Hypothesis vs Theory

A hypothesis is a testable prediction, while a theory is a well-substantiated explanation of an aspect of the natural world.

Fossil Record and Darwin

The fossil record provided evidence of gradual changes in species over time, supporting Darwin's theory of evolution.

Darwin's Research on the Galapagos Islands

Darwin observed unique species and variations that contributed to his understanding of natural selection and adaptation.

Main Ideas of Descent with Modification

Species evolve over time through gradual changes and adaptations, leading to diversity from a common ancestor.

Artificial Selection

The intentional breeding of organisms with desirable traits to produce offspring with those traits.

Evidence Supporting Evolution

Types of evidence include fossil records, comparative anatomy, molecular biology, and biogeography.

Analogy vs Homology

Analogy refers to similarities due to convergent evolution, while homology refers to similarities due to shared ancestry.

Molecular and Morphological Homology

Molecular homology refers to similarities in gene sequences, while morphological homology refers to structural similarities.

Fossil Record and Biogeography

Both provide evidence for evolution by showing historical changes in species distribution and characteristics over time.

Major Elements in Living Organisms

Key elements include carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur.

Structure of an Atom

Atoms consist of a nucleus containing protons and neutrons, surrounded by electrons in energy levels.

Atomic Mass vs Atomic Number

Atomic mass is the weighted average mass of an atom's isotopes, while atomic number is the number of protons in the nucleus.

Molecule vs Compound

A molecule is two or more atoms bonded together, while a compound is a molecule composed of different elements.

Isotope

Atoms of the same element that have the same number of protons but different numbers of neutrons.

Energy Levels of Electrons

Electrons occupy specific energy levels or shells around the nucleus, with higher energy levels further from the nucleus.

Valence Electrons

Electrons in the outermost shell of an atom that determine its chemical reactivity and bonding behavior.

Reactivity of Atoms

Atoms with unfilled outer shells are reactive, while those with filled outer shells (noble gases) are unreactive.

Chemical Bonds

Atoms with unfilled outer shells complete their valence shells through chemical bonds, such as covalent and ionic bonds.

Polar vs Non-Polar Covalent Bonds

Polar covalent bonds involve unequal sharing of electrons, while non-polar covalent bonds involve equal sharing.

Electronegativity

The tendency of an atom to attract electrons in a chemical bond, influencing bond polarity.

Types of Non-Covalent Bonds

The three types are ionic bonds (between atoms), hydrogen bonds, and van der Waals interactions (between molecules).

Molecule Shape and Function

The three-dimensional shape of a molecule is crucial for its function, as seen in enzyme-substrate interactions.

Chemical Reactions

Involve the making and breaking of chemical bonds, represented as reactants yielding products.

Balancing Chemical Equations

The process of ensuring that the number of atoms for each element is the same on both sides of a chemical equation using coefficients.