UNIT5 GENBIO DAY 2

UNIT 5: ANIMAL BIOLOGY PROCESSES IN ANIMALS

1. Overview

  • Focuses on processes in animals and homeostasis.

  • Importance of maintaining internal conditions with various structures and processes.

2. Homeostasis

2.1 Definition

  • Homeostasis: Ability to maintain internal stability in response to changes in the environment.

  • Example: Human body temperature regulation.

2.2 Types of Feedback Mechanisms

  • Negative Feedback:

    • A counteracting response to return to a set point.

    • Example: Body temperature regulation – when body temperature rises, blood vessels dilate; when it falls, blood vessels constrict.

  • Positive Feedback:

    • Amplifies a process or increases output.

    • Example: Uterine contractions during childbirth, where oxytocin is released to enhance contractions.

2.3 Types of Animals Based on Temperature Regulation

  • Endotherms:

    • Generate internal heat to maintain body temperature regardless of the environment.

    • Examples: Mammals, Birds.

  • Ectotherms:

    • Body temperature depends on external temperature.

    • Examples: Reptiles, Amphibians.

3. Addressing Animal Structure

3.1 Skeletal Structures

  • Internal Structures:

    • Bones or cartilage provide support.

  • External Structures:

    • Examples: Exoskeletons in arthropods like chitin.

  • Hydrostatic Skeleton:

    • Found in worms, utilizes water-filled cavities for structure and movement.

3.2 Symmetry in Animals

  • Types of Symmetry:

    • Asymmetrical: e.g., Porifera (sponges).

    • Radial: e.g., Cnidaria (jellyfish).

    • Bilateral: e.g., Platyhelminthes, Nematoda, Annelida, Arthropoda, Echinodermata, Chordata.

4. Animal Nutrition

4.1 Types of Feeding Strategies

  1. Herbivores:

    • Consume plants.

  2. Carnivores:

    • Consume other animals.

  3. Omnivores:

    • Consume both plants and animals.

  4. Detritivores:

    • Feed on decaying matter.

  5. Filter Feeders:

    • Extract food particles from water.

  6. Fluid Feeders:

    • Consume liquids directly from their environment.

5. Gas Exchange

5.1 Methods of Respiration

  • Respiration: Obtaining oxygen and expelling carbon dioxide.

  • Methods:

    • Gills: Used by aquatic animals.

    • Tracheae: Insects utilize this system.

    • Lungs: Used by most terrestrial animals.

5.2 Stages of Respiratory Process in Humans

  1. External Respiration: Breathing and gas exchange between lungs and blood.

  2. Internal Respiration: Gas exchange between blood and body cells.

  3. Cellular Respiration: Reactions within cells, particularly in mitochondria.

6. Transport Systems in Animals

6.1 Types of Circulatory Systems

  • Open Circulatory System:

    • Hemolymph pumped through vessels surrounding organs.

    • Common in arthropods.

  • Closed Circulatory System:

    • Blood confined within vessels, separating it from interstitial fluids.

    • Found in more advanced animals like vertebrates.

6.2 Components of Circulatory Systems

  • Heart: Central organ pumping blood or hemolymph.

  • Vessels: Tubular structures carrying fluids.

7. Animal Adaptations

7.1 Types of Adaptations

  • Structural: Physical features of an organism.

  • Behavioral: How an organism acts or behaves.

  • Functional: Internal processes that facilitate survival.

8. Reproduction in Animals

8.1 Types of Reproduction

  • Sexual Reproduction:

    • Involves two parents contributing genetic information.

  • Asexual Reproduction:

    • Offspring are genetically identical to the single parent.

8.2 Regeneration

  • The ability to repair or regrow damaged or missing parts, often seen in organisms like Hydra.

9. References

  • Morales-Ramos, A. C. and Ramos, J. D. (2017). Exploring Life through Science Series: General Biology 2. Phoenix Publishing House, Inc.

  • Online Sources: Byju’s (2023). Animal Kingdom - Animalia Phylum, Subphylum https://byjus.com/biology/animal-kingdom-animalia-subphylum/