Biology Chapter 3: Organisms and Adaptations

Locomotion

• Animals use muscular systems and specialized appendages (wings, fins) for movement (walking, flying, swimming, slithering).
• Plants use growth of roots towards moisture (positive hydrotropism) and the opening/closing of flowers.
• Fungi spread through mycelium, which helps them find nutrients.
• Protists move using tiny hairs (flagella) or pseudopodia.
• Monera use flagella or gliding mechanisms.

Reproduction

• Animals reproduce sexually (internal/external fertilization) or asexually.
• Environmental factors (seasonal changes, resource availability) influence animal reproductive cycles.
• Plant reproduction involves fertilization of seeds and pollination, or vegetative propagation (bulbs, runners).
• Fungi reproduce asexually through spore production or budding.
• Protists reproduce asexually through binary fission or budding.
• Monera reproduce asexually through binary fission.

Energy Acquisition

• Animals are heterotrophs, using digestive systems for mobility and predatory foraging.
• Plants are autotrophs, utilizing chloroplasts, leaves, and roots for structure and feeding.
• Fungi are heterotrophs, using mycelium for enzyme production and symbiotic relationships.
• Protists are autotrophs or heterotrophs, using chloroplasts, cilia, and flagella for feeding.
• Monera exhibit both autotrophic and heterotrophic metabolic pathways.

Response to Stimuli

• Light: Animals use light for navigation, mating, and predator avoidance. Plants exhibit phototropism (growing towards light).
• Gravity: Plant roots grow downward (positive gravitropism), stems upward (negative gravitropism). Animals maintain balance and orientation.
• Touch: Plants respond by closing traps or altering leaf positions; animals respond with reflexes or behavioural changes.
• Temperature: Some plants alter growth patterns in response to temperature changes. Animals change behaviour for temperature regulation (seeking shade).
• Water: Plant roots grow toward water (hydrotropism). Animals seek water or respond to salinity changes.
• Chemical signals: Plants release chemical compounds for defense or communication; animals use pheromones for communication.
• Sound: Certain plants may respond to sound vibrations. Animals rely on sound for communication and predator avoidance.
• Mechanical stress: Plants react to wind or mechanical stress by altering growth; animals flee from physical threats.

Other

• Photosynthesis: Plants use sunlight for energy conversion, forming chemical energy.
• Chemosynthesis: Some organisms use inorganic chemicals for energy production.
• Cellular respiration: Organisms utilize glucose to obtain cellular energy. ATP is the key energy currency in the cell.

Cellular components

• Chitin

• Cell wall components (cellulose, peptidoglycan)

• Unicellular organisms

  • Amoeba (pseudopods)- move through a process called amoeboid movement
  • Paramecium (cilia)- use cilia for propulsive force
  • Euglena (flagella)- use flagella for locomotion
  • Dinoflagellates (flagella)- uses two flagella for locomotion

• Archaea - single-celled microorganisms with structures similar to bacteria

• Microscopes: light, transmission electron, scanning electron microscopy

• Homeostasis: balance for survival and correct functions of body systems

Ethical Implications

• Ethical considerations of using model organisms for experimentation before experimenting on humans. Ethical concerns of methods and conditions.
• 3Rs: Replacement (use other alternatives), Reduction (reduce animal use), Refinement (less suffering)

Cost and Benefits of Reproductive Strategies

• Sexual reproduction leads to genetic diversity but needs more energy and time.
• Asexual reproduction is faster and more energy-efficient but results in identical offspring with little genetic diversity.
• K-strategy species (fewer offspring, high parental investment) thrive in stable environments.
• R-strategy species (high reproductive rate, less investment) flourish in unstable environments.

Behavioural, Structural, and Physiological Adaptations

• Behavioural adaptations: Actions or behaviours to avoid or reduce threats (innate or learned).
• Structural adaptations: Physical features for survival.
• Physiological adaptations: Internal bodily processes to regulate homeostasis.

Maintaining Homeostasis

• Biofeedback mechanisms return a system to its initial set point when it deviates from normalcy.

Fluid and Thermoregulation

• Multicellular organisms require fluid balance for cellular functions.
• Endotherms maintain body temperature internally; exotherms rely on external sources.

Biological Classification

• Carl Linnaeus (binomial nomenclature)- uses genus and species names (e.g., Panthera leo).
• Taxonomy categorizes organisms based on shared characteristics (Kingdom>Phylum>etc).