Biology Basics Quiz

Introduction to Biology

• Biology is the scientific study of living things (organisms), both living and dead (fossils).

Main Branches of Biology

• Zoology
• Botany
• Microbiology
• Virology
• Parasitology
• Mycology
• Entomology
• Marine Biology
• Ecology
• Evolutionary Biology
• Anatomy
• Physiology
• Immunology
• Neuroscience
• Cell Biology
• Molecular Biology
• Genetics
• Biochemistry
• Biotechnology
• Paleontology

Specialized Fields within Biology

• Biophysics
• Astrobiology
• Developmental Biology
• Biogeography
• Systems Biology
• Synthetic Biology
• Taxonomy
• Chronobiology
• Biometrics
• Bioinformatics
• Pharmacology
• Toxicology
• Biostatistics
• Cryobiology
• Ornithology
• Herpetology
• Ichthyology
• Limnology
• Ethology
• Oncology
• Dermatology
• Pathology
• Agricultural Biology
• Radiobiology

Goal of Biology

• Discovering and understanding the underlying unity and diversity of the complex processes that make up life.

Distinguishing Living from Nonliving Things

• Cellular structure and function
• Growth
• Development
• Metabolism
• Homeostasis
• Response to stimuli
• Reproduction
• Adaptation
• Evolution
• Limited lifespan

All Living Things Are Made of Cells

• Latin "cellula" = small room
• Cell: a small membrane-bound unit filled with a concentrated aqueous solution of chemicals, with reproduction capacity.
• All living things have similar cellular structure (same lipid-containing membrane, organelles, etc.).
• All cells have a similar chemical composition (carbohydrates, fatty acids, nucleic acids, and amino acids).
• Same 20 amino acids, same lipids, same sugars.
• Same chemical groups (methyl, hydroxyl, carboxyl, carbonyl, phosphoryl, amino, and thiol).

All Living Things Have Genetic Information in Their Cells

• Their genetic information is stored in DNA (deoxyribonucleic acid).
• DNA molecules are composed of four subunits called nucleotides.
• All DNA in a cell constitutes its genome.
• A segment of DNA that contains instructions for making a protein or an RNA is called a gene.

All Living Things Use Their Genetic Information the Same Way

• Genetic information flows from DNA to RNA (transcription) and from RNA to protein (translation).
• They use a universal genetic code to build proteins from their genomic information.

All Living Things Grow

• The mass of the organism increases by:
  • An increase in cell number
  • An increase in cell size

All Multicellular Living Things Develop from a Single Cell

• During development, specialized cells appear from non-specialized cells.
• This process of specialization is called cell differentiation.
• Cell differentiation involves changes in gene expression.

All Living Things Extract Energy and Raw Materials from the Environment

• Living organisms obtain nutrients from their environment.
• Biochemical reactions break down nutrient molecules.
• Chemical breakdown produces building blocks for structures and energy for cell work (mechanical, biochemical, and electrical).

All Living Things Regulate Their Internal Environment

• Maintenance of a constant internal environment is called homeostasis.
• Homeostasis requires cell activity regulation.
• Sensory, effector, and signaling mechanisms help integrate information.
• The major information systems of animals are the nervous, hormonal, and immune systems.
• They use chemical and electric signals to process information.

All Living Things Respond to Their Environment and Reproduce

• Living things respond to stimuli (reactions to change in environment)
• Reproduction:
  • Sexual: Male sperm, female sperm, zygote, embryo, baby
  • Asexual: Parent, developing bud, new bud, new hydra

The Genetic Information of All Living Things Changes Over Time

• Permanent changes in DNA sequence are called mutations.
• Most mutations are harmful (cancer, disorders, deformities).
• Some mutations are beneficial (polyploidy, resistance to chemicals and diseases).
• Evolution.

All Living Things Evolve

• Mutations lead to differences among individuals in a population.
• These differences affect their chances of survival and reproduction.
• The most adapted individuals survive and reproduce (natural selection).
• Mutations and natural selection account for the evolution of biodiversity on earth.

All These Similarities Point to a Common Ancestor

• These similarities indicate that the diverse organisms alive today all originated from one life form.

Biologists Trace the Evolutionary Tree of Life

• Identification, analysis, and quantification of similarities and differences among species help construct phylogenetic trees.
• Phylogenetic trees display the evolutionary history of different groups of organisms, including species' scientific names.

Each Species Is Given a Scientific Name (Binomial Name)

• The first part indicates the genus, and the second part indicates the species. Example: Homo sapiens.

The History of Life on Earth

• Earth formed around 4.6 billion years ago.
• Life appeared 600 million years later (~4 billion years ago).
• Photosynthesis: 2.5 billion years ago
• Eukaryotic cells: 2 billion years ago
• Multicellular organisms: 600 million years ago
• Modern humans: 500,000 years ago

Life Appeared through Chemical Evolution

• The critical step in the evolution of life was the appearance of nucleic acids.
• Nucleic acids could reproduce themselves and serve as templates for the synthesis of proteins.

The First Cell Appeared by the Enclosure of Biological Molecules by a Lipid Membrane

• Fatty acids make spherical structures called liposomes.
• In a primordial ocean, such membranous structures could have enveloped complex biological molecules.

Photosynthetic Organisms Changed Earth's Atmosphere

• Photosynthesis allows some organisms to capture energy from the Sun.
• Aerobic metabolism is far more efficient than anaerobic metabolism in extracting energy from nutrient molecules.
• With oxygen accumulation, life moved onto land (500 million years ago).

Eukaryotic Cells Probably Evolved in Several Steps

• Nuclear membranes and the endoplasmic reticulum (ER) may have evolved through invagination of the plasma membrane.
• Mitochondria are ancient aerobic prokaryotes engulfed by a pre-eukaryotic cell.
• Chloroplasts originated when a eukaryotic cell with mitochondria engulfed a photosynthetic prokaryote (via Endosymbiosis).
• Endosymbiosis is responsible for mitochondria and chloroplasts.

Multicellular Organisms Probably Evolved from Aggregated Eukaryotic Cells

• Aggregation: Single-celled organisms began to form colonies or groups, allowing cells to work together and share resources.
• Specialization: Within these colonies, cells started to specialize in different functions.

Evolution Led to the Appearance of the Three Domains of Life

• Bacteria, Archaea, and Eukarya.

Discoveries in Biology Can Be Generalized from Model Systems

• Examples of common model systems are mentioned in the image. These systems allow studies of basic biological processes.

Biologists Investigate Life Through Experiments That Test Hypotheses

• Observation and quantification are essential scientific skills.
• Scientific methods combine observation, experimentation, and logic.
• Good experiments can falsify hypotheses (using controlled/comparative experiments).
• Statistical methods are essential tools for scientific research (using null hypothesis, probability of error).

Comparative Experiments

• Collecting and comparing data from two or more groups.
• Groups differ in multiple unknown ways.
• Predicting a difference between groups
• Potentially difficult to isolate impact of one variable and to generalize.
• Confounding variables may influence results.

Controlled Experiments

• Predicting a critical factor/variable affects a phenomenon.
• All variables are held constant between groups.
• Studied organisms/cells are divided into two groups (manipulated/experimental and unmanipulated/control).
• Only the factor of interest is manipulated in the experimental group.
• The effect of the manipulated variable is investigated.
• Potentially difficult to design and execute.

Corals in Hot Water: A Scientific Investigation

• Reef-building corals provide shelter, breeding grounds, and food for marine species.
• Ocean warming causes corals to lose their essential microscopic algal partners (dinoflagellates). This is called "coral bleaching".
• Question: Are corals from warmer pools more resistant to bleaching?
• Hypothesis: Warmer-pool corals are less subject to bleaching under heat stress.
• Method: Transplanting corals and subjecting them to heat stress. Measuring chlorophyll levels.
• Results: Corals from both cool and warm pools bleached under heat stress. However, the warm pool corals showed less bleaching.
• Conclusion: Warm-pool corals are less affected by heat stress compared to cool-pool corals.

Why Understanding Biology Is Important

• Accurate scientific data helps in informed decisions, such as with Atlantic bluefin tunas.
• Knowledge of pathogenic organisms and their pathogenesis helps develop vaccines.
• Knowledge of genes and mechanisms responsible for genetic diseases helps in finding treatments and cures.
• Genetic engineering allows higher-yielding and more resistant crop plants (e.g., rice tolerant to herbicides or possessing beta-carotene.)

Learning Outcomes

• Listing major characteristics shared by all living things and outlining how cells share fundamental chemistry.
• Explaining concepts like genes, genomes, genetic information flow, cell differentiation, energy flow, material cycling, homeostasis, mutations, natural selection, adaptation, evolution and phylogenetic trees (evolutionary relationships).
• Explaining how genetic information establishes evolutionary relationships and describing data representation in phylogenetic trees.
• Explaining the history of life on earth (first cell, photosynthesis, eukaryotic cells, multicellularity, domains of life evolution).
• Explaining and contrasting controlled and comparative experiments (scientific method principles).
• Explaining the need for understanding biology in health, agricultural improvement, and environmental preservation.

Test your knowledge of fundamental biology concepts with this quiz. Covering topics such as experimental design, cellular functions, and ecological roles, it’s perfect for students beginning their journey in biological sciences. See how well you understand the principles that govern life sciences!