Cell Biology and Genetics Quiz

Cell Biology

• Cell Structure:

  • Prokaryotic vs. Eukaryotic Cells:
    • Prokaryotic: no nucleus, smaller, simpler (e.g. bacteria).
    • Eukaryotic: nucleus present, larger, complex (e.g. plant and animal cells).
  • Organelles:
    • Nucleus: contains DNA.
    • Mitochondria: powerhouse of the cell, energy production.
    • Ribosomes: protein synthesis.
    • Endoplasmic Reticulum: synthesis of proteins (rough) and lipids (smooth).
    • Golgi Apparatus: packaging and distribution of proteins.

• Cell Membrane:

  • Phospholipid bilayer with embedded proteins.
  • Functions: selective permeability, communication, and transport.

• Cell Division:

  • Mitosis: process of cell division for growth and repair.
  • Meiosis: cell division for gamete formation in sexual reproduction.

Genetics

• Basic Concepts:

  • Gene: unit of heredity, made up of DNA.
  • Allele: different forms of a gene.
  • Genotype vs. Phenotype:
    • Genotype: genetic makeup.
    • Phenotype: physical expression of the genotype.

• Mendelian Genetics:

  • Law of Segregation: allele pairs separate during gamete formation.
  • Law of Independent Assortment: genes for different traits segregate independently.

• DNA Structure and Function:

  • Double helix formed by nucleotides (A, T, C, G).
  • Replication: process of copying DNA before cell division.
  • Transcription and Translation: processes of protein synthesis.

Ecology

• Ecosystems:

  • Components: biotic (living organisms) and abiotic (non-living environment).
  • Energy Flow: primary producers (plants) → consumers (animals) → decomposers (fungi/bacteria).

• Biomes:

  • Major types: terrestrial (e.g. forests, deserts) and aquatic (e.g. freshwater, marine).

• Population Dynamics:

  • Factors affecting populations: birth rate, death rate, immigration, emigration.
  • Carrying capacity: maximum population size that an environment can sustain.

Evolution

• Theory of Evolution:

  • Natural Selection: process by which organisms better adapted to their environment survive and reproduce.
  • Variation: differences among individuals in a population.
  • Speciation: formation of new and distinct species in the course of evolution.

• Evidence of Evolution:

  • Fossil records, comparative anatomy, molecular biology, and biogeography.

• Key Concepts:

  • Adaptation: inherited trait that enhances survival/reproduction.
  • Genetic Drift: variation in allele frequencies due to random events.

Nervous System

• Structure:

  • Central Nervous System (CNS): brain and spinal cord.
  • Peripheral Nervous System (PNS): all nerves outside the CNS.

• Neurons:

  • Basic unit of the nervous system; consists of dendrites, cell body, and axon.
  • Types: sensory (afferent), motor (efferent), and interneurons.

• Signal Transmission:

  • Action potential: electrical impulse that travels along neurons.
  • Synapses: gaps between neurons where neurotransmitters are released to transmit signals.

• Functional Systems:

  • Somatic Nervous System: controls voluntary movements.
  • Autonomic Nervous System: regulates involuntary functions (divided into sympathetic and parasympathetic systems).

Cell Structure

• Prokaryotic cells are simpler, lacking a nucleus and other membrane-bound organelles, while eukaryotic cells are more complex and possess a nucleus and various organelles.
• The nucleus houses the cell's genetic material (DNA)
• Mitochondria are responsible for energy production through cellular respiration.
• Ribosomes are crucial for protein synthesis.
• The endoplasmic reticulum (ER) plays a role in protein and lipid synthesis.
• The Golgi apparatus modifies, sorts, and packages proteins for secretion or transport within the cell.
• The cell membrane is a phospholipid bilayer with embedded proteins that regulates the passage of substances into and out of the cell.

Cell Division

• Mitosis is a process of cell division that produces two identical daughter cells, essential for growth and repair.
• Meiosis is a specialized cell division that produces gametes (sperm and egg cells) with half the number of chromosomes as the parent cell, crucial for sexual reproduction.

Genetics

• Genes are segments of DNA that carry the instructions for building and maintaining an organism.
• Alleles are alternative forms of a gene.
• The genotype refers to an individual's genetic makeup, while the phenotype is the observable physical or biochemical characteristics determined by the genotype.
• Gregor Mendel's laws of heredity, including the law of segregation and the law of independent assortment, provide a fundamental understanding of how traits are passed from parents to offspring.
• DNA, the molecule of life, carries genetic information in its unique double-helix structure.
• DNA replication creates an exact copy of the DNA molecule before cell division, ensuring that genetic information is passed accurately to daughter cells.
• Transcription and translation are crucial steps in protein synthesis, where the genetic information encoded in DNA is used to build proteins.

Ecology

• An ecosystem encompasses all living organisms (biotic components) and their non-living environment (abiotic components).
• Energy flows through an ecosystem, beginning with primary producers (plants) that capture sunlight via photosynthesis.
• Consumers (animals) obtain energy by eating primary producers or other consumers.
• Decomposers (fungi and bacteria) break down dead organisms and waste products, releasing nutrients back into the ecosystem.
• Biomes are large-scale ecosystems characterized by distinct climates, vegetation, and animal life.
• Terrestrial biomes include forests, deserts, grasslands, and tundra, while aquatic biomes include freshwater and marine ecosystems.
• Population dynamics refer to changes in population size over time, influenced by factors such as birth rate, death rate, immigration, and emigration.
• Carrying capacity is the maximum population size that a particular environment can sustainably support.

Evolution

• Charles Darwin's theory of evolution by natural selection explains how organisms adapt and diversify over time.
• Natural selection favors individuals with traits that enhance their survival and reproduction in a given environment.
• Variation within populations arises from genetic mutations and sexual reproduction.
• Speciation occurs when populations diverge genetically and become reproductively isolated, leading to the formation of new species.
• Evidence for evolution includes fossil records that document changes in life forms over time, comparative anatomy that reveals similarities in body structures between related species, molecular biology that compares DNA sequences to trace evolutionary relationships, and biogeography that studies the distribution of species across the globe.
• Adaptation is an inherited trait that increases an organism's fitness, enhancing its ability to survive and reproduce.
• Genetic drift is a random fluctuation in allele frequencies within a population, particularly noticeable in small populations.

Nervous System

• The nervous system is responsible for coordinating and controlling bodily functions through electrical and chemical signals.
• The central nervous system (CNS) consists of the brain and spinal cord, while the peripheral nervous system (PNS) comprises all nerves outside the CNS.
• Neurons, the basic units of the nervous system, are specialized cells that transmit signals.
• Neurons have three main parts: dendrites, which receive signals; a cell body, which integrates signals; and an axon, which transmits signals to other cells.
• There are three types of neurons: sensory (afferent) neurons transmit signals from sensory receptors to the CNS; motor (efferent) neurons transmit signals from the CNS to muscles and glands; and interneurons connect neurons within the CNS.
• Action potentials are electrical impulses that travel along neurons, carrying information from one part of the nervous system to another.
• Synapses are junctions between neurons, where neurotransmitters are released from the presynaptic neuron to transmit signals to the postsynaptic neuron.
• The somatic nervous system controls voluntary movements, while the autonomic nervous system regulates involuntary functions such as heart rate, digestion, and breathing.
• The autonomic nervous system is further divided into the sympathetic nervous system, which prepares the body for action ("fight or flight"), and the parasympathetic nervous system, which promotes relaxation and rest.

Test your knowledge on cell structure, including the differences between prokaryotic and eukaryotic cells, and the function of organelles. Additionally, assess your understanding of basic genetics concepts such as genes, alleles, and the distinction between genotype and phenotype.