BIOLOGY

• Few Reminders: Mute your audio when has nothing to say important. Unmute your audio and excuse yourself when you have to say something. When someone has already unmuted his/her audio, let him/her finish first. Practice respect throughout the class hours. Focus and take down notes.
• Explain the postulates of the Cell Theory
• Describe the structure and functions of major and subcellular organelles
• Distinguish prokaryotic and eukaryotic cells according to their distinguishing features
• Classify different cell types (of plant and animal tissues) and specify the functions of each
• Describe some cell modifications that lead to adaptation to carry out specialized functions (roothairs, microvilli)
• Most Essential Learning Competencies (MELCs)


  Is it worthy to understand what cell is? How can we keep ourselves healthy knowing the basic unit of life?
• Plant Tissues and their Cells
• Animal Tissues and their Cells
• Plant and Animal Tissues and their Cells
• Plant Anatomy and Structure
• Type of Plant Cells
• Type of Plant Tissues
• Epithelial Tissue
• Connective Tissue
• Muscular Tissue
• Nervous Tissue
• Root Hairs and Microvilli
• Plant Tissues


  A collection of similar cells performing an organized function for the plant. Two general types: meristematic tissue and permanent tissue.
• Meristematic Tissues


  • Apical Meristem
  • Lateral Meristem
  • Intercalary Meristem
• Meristematic Tissues


  Greek word; meristos- means "divisible". Meristematic tissue is a group of cells that has power of continuous division. Cells are immature and young.
• Apical Meristem


  • Existent at the growing tips or apical of stems and roots. It upsurges the length of the plant which is called primary growth. The cells divide rapidly and are considered to be indeterminate, which means that they do not possess any defined end fate.
• Lateral Meristem


  • Present on the lateral side of the stem and root of a plant. Responsible for secondary growth, or increase in stem girth and thickness.
• Types of Lateral Meristem

  • Vascular Cambium
  • Cork Cambium
• Intercalary Meristem


  • Located at the internodes or the base of the leaves. Help in increasing the length of the internode. Usually seen in monocotyledonous plants.
• Permanent Tissues


  The permanent tissues in a plant are those tissues that contain non dividing cells. The cells are also modified to perform specific functions in the plants.
• Types of Permanent Tissues

  • Simple Permanent Tissues
  • Complex Permanent Tissues
• Characteristics of Permanent Tissues

  • Permanent cells have lost their power of division except parenchyma. They are derived from meristematic tissue. Their cells show large vacuoles. Their cells are well differentiated and are found in a variety of shapes. The metabolic activity is low in these cells compared to meristematic tissues. Permanent tissues may be either simple or complex in nature.
• Simple Permanent Tissues


  • Dermal Tissues
  • Ground Tissues
• Dermal Tissues


  Dermal tissue is found covering the younger primary parts of a plant. Plant parts that become woody no longer have dermal tissue as their outer layer because it is replaced by periderm or cork. The dermal layer of a plant is its first line of defense. It control the exchange of oxygen and carbon dioxide gases and the release of water vapor.
• Ground Tissues


  The ground tissue of the vascular plant is responsible for storing the carbohydrates produced by the plant. Ground tissue comprises the majority of a young plant and lies between the vascular and dermal tissues.
• Three Simple Tissues


  • Parenchyma
  • Collenchyma
  • Sclerenchyma
• Parenchyma


  Greek para, meaning beside, and egchnma, meaning the contents of a pitcher (literally, something poured beside). Parenchyma cells are active in secretion, photosynthesis, and water and food storage. Parenchyma cells do not have a secondary cell wall at maturity and thus remain flexible and capable of elongation and is capable of cell division.
• Collenchyma


  Found chiefly in the cortex of stems and in leaves and is located along the periphery of stems beneath the epidermal tissue. It may form a complete cylinder or occur as discrete strands that constitute the ridges and angles of stems and other supporting structures of the plant. It provides flexibility so plants can bend.
• Sclerenchyma


  Usually dead at maturity. They characteristically contain very thick, hard secondary walls lined with lignin; consequently, sclerenchyma provides additional support and strength to the plant body. The two principal types are sclereids and fibres.
• Types of Sclerenchyma


  • Sclereids
  • Fibres
• Sclereids


  Sclereids vary in shape and size and may be branched. They are common in seed coats and nutshells. Apart from providing some internal support for various plant organs, sclereids deter desiccation of hard seeds, such as beans, and discourage herbivory of certain leaves.
• Fibres


  Slender cells, many times longer than they are wide. They are highly lignified cells with tapering (oblique) end walls. The side walls of fibres are often so thick that the centre of the cell (the lumen) is often occluded. Fibres have great tensile strength and yet are also elastic.
• Complex Permanent Tissues


  Made up of more than one type of cell. They coordinate together to perform the same specialized functions in the plant body.
• Vascular Tissues


  An arrangement of multiple cell types in vascular plants which allows for the transport of water, minerals, and products of photosynthesis to be transported throughout the plant. Vascular tissue functions mainly in maintaining the water balance and sugar balance of a plant.