Model Answer
0 min readIntroduction
Cell division is a fundamental biological process enabling growth, repair, and reproduction in all living organisms. It’s the process by which a parent cell divides into two or more daughter cells. In animals, the primary modes are mitosis (for growth and repair) and meiosis (for sexual reproduction). The adult animal body is a complex assembly of diverse tissues, each specialized for specific functions. These tissues work in coordinated harmony to ensure survival and proper physiological functioning. Understanding these tissues and their roles is critical for comprehending animal physiology and health.
Cell Division: A Brief Overview
Cell division ensures the continuity of life. There are two main types:
- Mitosis: This process produces two genetically identical daughter cells and is essential for growth, repair, and asexual reproduction. It involves distinct phases: prophase, metaphase, anaphase, and telophase.
- Meiosis: This process produces four genetically unique daughter cells (gametes) with half the number of chromosomes. It's crucial for sexual reproduction, promoting genetic diversity.
Functions of Different Body Tissues in Adult Animals
1. Epithelial Tissue
Epithelial tissue covers body surfaces, lines cavities, and forms glands. Its primary functions include:
- Protection: Skin epithelium protects against physical damage, pathogens, and dehydration.
- Absorption: Epithelium in the small intestine absorbs nutrients.
- Secretion: Glandular epithelium secretes hormones, enzymes, and mucus. For example, goblet cells in the respiratory tract secrete mucus to trap pathogens.
- Excretion: Kidney tubules excrete waste products.
2. Connective Tissue
Connective tissue supports, connects, and separates different tissues and organs. Examples include bone, cartilage, blood, and adipose tissue.
- Support and Structure: Bone provides skeletal framework and cartilage provides support in joints.
- Transport: Blood transports oxygen, nutrients, and hormones.
- Storage: Adipose tissue stores energy in the form of fat.
- Immune Defense: Connective tissue contains immune cells that protect against infection.
3. Muscular Tissue
Muscular tissue is responsible for movement.
- Skeletal Muscle: Voluntary movement, e.g., walking.
- Smooth Muscle: Involuntary movements like peristalsis in the digestive system.
- Cardiac Muscle: Contraction of the heart to pump blood.
4. Nervous Tissue
Nervous tissue transmits electrical signals throughout the body.
- Sensory Perception: Detects stimuli from the environment (e.g., touch, taste, smell).
- Coordination and Control: Brain and spinal cord coordinate bodily functions.
- Communication: Neurons transmit signals between different parts of the body.
| Tissue Type | Primary Functions |
|---|---|
| Epithelial | Protection, Absorption, Secretion, Excretion |
| Connective | Support, Transport, Storage, Immune Defense |
| Muscular | Movement (Voluntary & Involuntary) |
| Nervous | Sensory Perception, Coordination, Communication |
Conclusion
In conclusion, cell division is the bedrock of growth and repair, while the coordinated functions of epithelial, connective, muscular, and nervous tissues are vital for maintaining homeostasis and enabling complex animal life processes. Understanding the specialized roles of these tissues is essential for appreciating the intricacies of animal physiology. Future research focusing on tissue regeneration and personalized medicine promises to further enhance our understanding and therapeutic interventions related to tissue function and repair.
Answer Length
This is a comprehensive model answer for learning purposes and may exceed the word limit. In the exam, always adhere to the prescribed word count.