Biology Quiz: Cell Structure and Genetics

Cell Structure and Function

• Cell Types:

  • Prokaryotic: No nucleus, smaller, unicellular.
  • Eukaryotic: Nucleus present, larger, can be unicellular or multicellular.

• Organelles:

  • Nucleus: Contains genetic material (DNA).
  • Mitochondria: Powerhouse of the cell, produces ATP.
  • Ribosomes: Site of protein synthesis.
  • Endoplasmic Reticulum (ER):
    • Rough ER: Studded with ribosomes, synthesizes proteins.
    • Smooth ER: Synthesizes lipids, detoxifies chemicals.
  • Golgi Apparatus: Modifies, sorts, and packages proteins and lipids.

Genetics

• DNA Structure:

  • Double helix composed of nucleotides (A, T, C, G).

• Gene Expression:

  • Transcription: DNA to mRNA.
  • Translation: mRNA to protein.

• Mendelian Genetics:

  • Laws of Segregation and Independent Assortment.
  • Genotype vs. Phenotype.

Evolution

• Natural Selection:

  • Mechanism of evolution where organisms better adapted to their environment tend to survive and reproduce.

• Speciation:

  • Process by which new species arise, often due to geographic isolation.

Ecology

• Biomes:

  • Large ecological areas with distinct climates and organisms (e.g., tundra, rainforest).

• Food Chains and Food Webs:

  • Food Chain: Linear sequence illustrating energy transfer.
  • Food Web: Complex interconnections of food chains.

• Population Dynamics:

  • Factors affecting population size: birth rate, death rate, immigration, emigration.

Human Biology

• Body Systems:

  • Circulatory: Transports blood and nutrients.
  • Respiratory: Exchanges gases with the environment.
  • Digestive: Breaks down food into nutrients.

• Homeostasis:

  • The process of maintaining a stable internal environment despite external changes.

Microbiology

• Bacteria:

  • Prokaryotic organisms found in diverse environments, some pathogenic.

• Viruses:

  • Non-living entities that require a host cell to reproduce, consist of genetic material surrounded by protein.

Plant Biology

• Photosynthesis:

  • Conversion of light energy into chemical energy using chlorophyll in chloroplasts.
  • Basic equation: CO2 + H2O + light energy → C6H12O6 + O2.

• Plant Anatomy:

  • Roots: Absorb water and nutrients.
  • Stems: Support and transport substances.
  • Leaves: Primary site of photosynthesis.

Biochemistry

• Macromolecules:
  • Carbohydrates: Energy source (sugars, starch).
  • Proteins: Made of amino acids, perform various functions.
  • Lipids: Fats and oils, important for cell membranes and energy storage.
  • Nucleic Acids: DNA and RNA, carry genetic information.

Cell Structure and Function

• Prokaryotic Cells: Lack a nucleus and are generally smaller than eukaryotic cells; they are all unicellular.
• Eukaryotic Cells: Possess a nucleus, are typically larger than prokaryotic cells, and can be unicellular or multicellular.
• Organelles: Structures within cells with specific functions
  • Nucleus: Contains DNA, the cell's genetic material.
  • Mitochondria: The "powerhouse" of the cell responsible for generating energy (ATP) through respiration.
  • Ribosomes: Sites of protein synthesis, using the genetic instructions from DNA.
  • Endoplasmic Reticulum (ER): A network of membranes involved in various processes.
    • Rough ER: Studded with ribosomes and helps synthesize proteins.
    • Smooth ER: Synthesizes lipids and detoxifies harmful chemicals.
  • Golgi Apparatus: Modifies, sorts, and packages proteins and lipids for transport within or outside the cell.

Genetics

• DNA Structure: DNA is a double helix composed of nucleotides, which are building blocks consisting of a sugar, a phosphate group, and one of four nitrogenous bases: Adenine (A), Thymine (T), Cytosine (C), and Guanine (G).
• Gene Expression: The process by which the information in DNA is used to create functional proteins
  • Transcription: DNA is copied into messenger RNA (mRNA).
  • Translation: mRNA is decoded by ribosomes to create a protein.
• Mendelian Genetics: Principles governing inheritance patterns
  • Laws of Segregation: During gamete formation, alleles (alternative forms of a gene) separate so that each gamete receives only one allele.
  • Law of Independent Assortment: Alleles for different traits separate independently during gamete formation.
  • Genotype: An organism's genetic makeup.
  • Phenotype: An organism's observable characteristics.

Evolution

• Natural Selection: A driving force behind evolution where individuals with traits better suited to their environment are more likely to survive, reproduce, and pass those advantageous traits to their offspring.
• Speciation: The evolutionary process by which new species arise.
  • Geographic Isolation: Separation of populations, preventing gene flow and leading to genetic divergence, potentially resulting in new species.

Ecology

• Biomes: Large-scale ecosystems characterized by distinct climates (temperature, precipitation) and vegetation, supporting unique communities of organisms. Examples include tundra, rainforest, desert, and grasslands.
• Food Chains and Food Webs:
  • Food Chain: A linear sequence illustrating the flow of energy through different trophic levels (producer, consumer, decomposer) in an ecosystem.
  • Food Web: A complex network of interconnected food chains, representing the intricate relationships and energy flow within an ecosystem.
• Population Dynamics: Factors affecting population size over time:
  • Birth Rate: The number of births per unit of time.
  • Death Rate: The number of deaths per unit of time.
  • Immigration: The movement of individuals into a population.
  • Emigration: The movement of individuals out of a population.

Human Biology

• Body Systems: Groups of organs working together to perform specific functions:
  • Circulatory System: Transports blood, oxygen, nutrients, and waste products throughout the body.
  • Respiratory System: Responsible for gas exchange, taking in oxygen and releasing carbon dioxide.
  • Digestive System: Breaks down food into smaller molecules that can be absorbed by the body.
• Homeostasis: The maintenance of a stable internal environment within the body, despite external changes. This involves processes like regulating temperature, pH, blood glucose levels, etc.

Microbiology

• Bacteria: Single-celled prokaryotic organisms that are found in diverse environments. Some bacteria are beneficial, while others can cause disease (pathogenic).
• Viruses: Non-living entities that consist of genetic material (DNA or RNA) surrounded by a protein coat. They can replicate only inside a host cell.

### Plant Biology

• Photosynthesis: The process by which plants convert light energy into chemical energy (sugars) using chlorophyll (a green pigment) found in chloroplasts.
  • Basic Equation: CO2 + H2O + light energy → C6H12O6 + O2 (carbon dioxide and water are converted into glucose and oxygen)
• Plant Anatomy:
  • Roots: Anchor the plant, absorb water and nutrients from the soil.
  • Stems: Provide support for the plant and transport water and nutrients from roots to leaves.
  • Leaves: Primary site of photosynthesis, containing chlorophyll to capture light energy.
  • Flowers: Reproductive organs responsible for seed production.

Biochemistry

• Macromolecules: Large complex molecules essential for life:
  • Carbohydrates: Consist of sugars and starches, primarily used for energy storage.
  • Proteins: Made up of long chains of amino acids, perform a wide range of functions (enzymes, structural components, antibodies, hormones).
  • Lipids: Fats and oils, important for energy storage, cell membrane structure, and insulation.
  • Nucleic Acids: DNA and RNA, carry genetic information, determining traits and guiding protein synthesis.

Test your knowledge on cell structure, organelles, and genetics. This quiz covers key concepts like prokaryotic and eukaryotic cells, DNA structure, gene expression, and the principles of Mendelian genetics. Dive into the basics of evolution and natural selection as well.