Overview
This lecture covers the classification, structure, and functions of animal and plant tissues, focusing on cell components, tissue types, and key biological terms and processes.
Classification of Tissues
- Tissues are classified as simple (one cell type) or complex (multiple cell types).
- Plant tissues include simple (parenchyma, collenchyma, sclerenchyma) and complex tissues (xylem, phloem).
- Animal tissues are classified into epithelial, connective, muscular, and nervous tissues.
Structure and Function of Animal Cells
- An animal cell contains a nucleus, cytoplasm, cell membrane, and various organelles.
- The nucleus acts as the control center or "brain" of the cell.
- The nuclear envelope surrounds the nucleoplasm and nuclear reticulum.
- Key organelles include mitochondria (powerhouse, ATP production), ribosomes (protein synthesis), and endoplasmic reticulum.
- The plasma membrane is mainly made of proteins and lipids.
Cell Types and Reproduction
- Somatic cells are body cells; reproductive cells are involved in reproduction.
- Reproduction involves the process of cell division (mitosis and meiosis).
- Chromosomes are made of DNA, which carries genetic information.
Plant Cell Structures and Functions
- Plant cells have a cell wall (made of cellulose, hemicellulose, pectin) for support.
- Key organelles: chloroplasts (photosynthesis), mitochondria (energy), vacuole (storage).
- Plastids include chloroplasts (green pigment), chromoplasts (color pigments), and leucoplasts (storage).
Tissue Details and Functions
- Xylem and phloem are complex plant tissues forming vascular bundles.
- Sclerenchyma provides support; parenchyma is involved in storage and photosynthesis.
- Animal connective tissues include bone, cartilage, blood, and adipose (fat).
- Muscular tissue contains actin and myosin for contraction.
Key Terms & Definitions
- Tissue — Group of cells with a similar structure and function.
- Nucleus — Organelle controlling cell activities; contains DNA.
- Mitochondria — Organelle for cellular respiration and energy production.
- Ribosome — Organelle synthesizing proteins.
- Chromosome — DNA molecule carrying genetic instructions.
- Polysaccharide — Complex carbohydrate (e.g., cellulose, starch).
- Plastid — Plant organelle for synthesis/storage of food and pigments.
- Xylem/Phloem — Plant vascular tissues for water and nutrient transport.
Action Items / Next Steps
- Draw labeled diagrams of animal and plant cells.
- Practice classifying tissues and identifying their functions.
- Review and memorize key terms and organelle functions.
- Solve MCQs related to tissue types and cell structures.