Eu_Prp_Cell_Specialization_CellModification.pdf

Distinguish prokaryotic Classify different cell and eukaryotic cells types (of plant/animal according to their tissues) and specify the distinguishing features. fun...

Distinguish prokaryotic Classify different cell and eukaryotic cells types (of plant/animal according to their tissues) and specify the distinguishing features. functions of each. Describe some cell modifications that lead to adaptation to carry out specialized functions. Prokaryotic vs Eukaryotic Cells Prokaryotic vs Eukaryotic Cells  COMMON MISTAKES AND MISCONCEPTIONS Eukaryotes can be unicellular Even though prokaryotes do not have a nucleus, they DO contain genetic information Though they sound negative, bacteria are very important  “pro”- before + “karyon” - kernel or nut simple, unicellular organisms that do not have a nucleus and membrane-bound organelles. most of its DNA is found in what is known as the nucleoid region.  “eu”- good, well or true + “karyon”- kernel or nut organisms whose cell has a nucleus enclosed by a membrane. other organelles are also bound by membranes. Picture Analysis Identify the pictures!!!  also known as cell differentiation. it is the process by which generic cells change to different types of cells to be able to perform special or specific functions. Specialized Cells in Animals Specialized Cells in Animals Specialized Cells in Animals Specialized Cells in Plants Specialized Cells in Plants  -adaptations or changes acquired by the cell after cell division that aids the cell in various beneficial ways.  hair- like organelles extending from the cell surface types of cilia ⚬ non-motile or primary cilia (sensory) ⚬ motile (movement)  long, whip -like structures made of protein filaments aids in movement  small, slender, vascular, finger- like projections increases surface area to increase absorption  false feet temporary extension of the cytoplasm movement and ingestion (phagocytosis Cell Types epithelial cells connective tissue cells muscle cells nerve cells Epithelial Tissue This type of tissue is commonly seen outside the body as coverings or as linings of organs and cavities. Epithelial tissues are characterized by closely-joined cells with tight junctions (i.e., a type of cell modification). Epithelial Tissue Epithelial Tissue  Cells that make up epithelial tissues can have distinct arrangements:  cuboidal—for secretion  simple columnar—brick-shaped cells; for secretion and active absorption  simple squamous—plate-like cells; for exchange of material through diffusion  stratified squamous—multilayered and regenerates quickly; for protection  pseudo-stratified columnar—single layer of cells; may just look stacked because of varying height; for lining of respiratory tract; usually lined with cilia (i.e., a type of cell modification that sweeps the mucus). Connective Tissues Connective Tissue—These tissues are composed of the following: BLOOD —made up of plasma (i.e., liquid extracellular matrix); contains water, salts, and dissolved proteins; erythrocytes that carry oxygen (RBC), leukocytes for defense (WBC), and platelets for blood clotting. CONNECTIVE TISSUE PROPER (CTP)—made up of loose connective tissue that is found in the skin and fibrous connective tissue that is made up of collagenous fibers found in tendons and ligaments. Adipose tissues are also examples of loose connective tissues that store fats which functions to insulate the body and store energy. CARTILAGE —characterized by collagenous fibers embedded in chondroitin sulfate. Chondrocytes are the cells that secrete collagen and chondroitin sulfate. Cartilage functions as cushion between bones. BONE —mineralized connective tissue made by bone- forming cells called osteoblasts which deposit collagen. The matrix of collagen is combined with calcium, magnesium, and phosphate ions to make the bone hard. Blood vessels and nerves are found at a central canal surrounded by concentric circles of osteons. Muscle Tissue These tissues are composed of long cells called muscle fibers that allow the body to move voluntary or involuntary. Movement of muscles is a response to signals coming from nerve cells. In vertebrates, these muscles can be categorized into the following: skeletal—striated; voluntary movements cardiac—striated with intercalated disk for synchronized heart contraction; involuntary smooth—not striated; involuntary  These tissues are composed of nerve Nervous cells called neurons and glial cells that Tissue function as support cells. These neurons sense stimuli and transmit electrical signals throughout the animal body. Neurons connect to other neurons to send signals. Plant Tissues Plant tissues, primarily function is to give structural support to the plant, as plants are stationary. Plant tissues can be divided differently into two types; Meristematic tissues Permanent tissues.  1. Meristematic Tissues  It consists of actively dividing cells that lead to the increase in length and thickness of the plant.  The primary growth of a plant occurs only in certain, specific regions, such as in the tips of stems or roots. It is in these regions that meristematic tissue is present. The cells in these tissues are roughly spherical to rectangular in shape and have thin cell walls. New cells produced by meristem are initially those of meristem itself, but as the new cells grow and mature, their characteristics slowly change, and they become differentiated.  a. Apical meristem It is present at the growing tips of stems and roots and increases the length of the stem and root. They form growing parts at the apices of roots and stems and are responsible for increase in length, also called primary growth. This meristem is responsible for the linear growth of an organ. b. Lateral meristem This meristem consist of cells, which mainly divide in one plane and cause the organ to increase in diameter and grows. Lateral meristem usually occurs beneath the bark c. Intercalary Meristem This meristem is located in between permanent tissues. It is usually present at the base of the node, inter node and on leaf base. They are responsible for growth in length of the plant and increasing the size of the internode, They result in branch formation and growth.  2. Permanent tissues Plant tissues that contain nondividing cells that was derived from meristematic tissues. 2.1 Simple Permanent tissues- A group of cells which are similar in origin; similar in structure and similar in function. They are of three types; Parenchyma Collenchyma Sclerenchyma  a. Parenchyma  Parenchyma (para - 'beside'; chyma - 'in filling, loose, unpacked') is the bulk of a substance. In plants, it consists of relatively unspecialized living cells with thin cell walls. This tissue provides support to plants and also store food. In some situations, a parenchyma contains chlorophyll and performs photosynthesis, in which case it is called a chlorenchyma. In aquatic plants, large air cavities are present in parenchyma to give support to them to float on water. Such a parenchyma type is called aerenchyma. b. Collenchyma Collenchyma is Greek word where "Collen" means gum and "chyma" means infusion. This tissue gives a tensile strength of the plant, and the cells are compactly arranged and have very little inter- cellular spaces. It occurs chiefly in the hypodermis of stems and leaves. It is absent in monocots and in roots.  c. Sclerenchyma Sclerenchyma is Greek word where "Sclerenes" means hard and "chyma" means infusion. This tissue consists of thick- walled, dead cells. These cells have hard and extremely thick secondary walls due to uniform distribution of lignin. Lignin deposition is so thick that the cell walls become strong, rigid and impermeable to water.  2.2 Complex Permanent tissues  The complex tissue consists of more than one type of cells, which work together as a unit. Complex tissues help in the transportation of organic material, water and minerals up and down the plants. That is why it is also known as conducting and vascular tissue.  The common types of complex permanent tissue are:  Xylem  Phloem.  a. Xylem b. Phloem  consists of a variety of  It is composed of various specialized, water-conducting specialized cells called sieve cells known as tracheary tubes, companion cells, phloem elements. A vascular tissue that fibers, and phloem parenchyma conveys water and dissolved cells. This are tissues in plants minerals from the roots to the that conduct foods made in the rest of the plant and provides leaves to all other parts of the physical support also. plant.