Modified-Cells.pdf Biology Lesson

Lesson 2.4 Structures and Functions of Modified Cells General Biology 11/2 Science, Technology, Engineering, and Mathematics Have you ever wondered what your talents are? 2 Why do we consider this a fish? 3 What makes these animals unique?...

Lesson 2.4 Structures and Functions of Modified Cells General Biology 11/2 Science, Technology, Engineering, and Mathematics Have you ever wondered what your talents are? 2 Why do we consider this a fish? 3 What makes these animals unique? 4 What makes us unique as humans? 5 Organisms’ special structures and abilities are developed based on what they need to survive or to adapt in their environments. 6 Similarly, microscopic structures in the body are specialized in that they carry out activities that other structures cannot. 7 What do special microscopic structures look like? How do they function? 8 Learning Competency At the end of the lesson, you should be able to do the following: Describe some cell modifications that lead to adaptation to carry out specialized functions (e.g., microvilli, root hair) (STEM_BIO11/12-Ia-c-5). 9  Learning Objectives At the end of the lesson, you should be able to do the following: Enumerate the specialized cells in animals and plants. Locate the specialized cells in animals and plants. Determine the functions of each specialized cell in animals and plants. 10 Specialized Cells and Cell Structures Parts of a typical animal cell 11 What are the specialized cells in animals? What makes them essential components of the animal body? 12  Specialized Cells and Cell Structures in Animals Microvilli Cilia and Stereocilia Flagella Basal Infoldings and Hemidesmosomes Cell Junctions Blood Cells and Sex Cells The microvilli in the small intestine 13  Specialized Cells and Cell Structures in Animals Microvilli Function of Microvilli Cilia and Stereocilia These increase the surface area for Flagella the absorption of nutrients and other Basal Infoldings and essential substances from the gut Hemidesmosomes cavity into the underlying tissues and Cell Junctions blood vessels. Blood Cells and Sex Cells 14  Specialized Cells and Cell Structures in Animals Microvilli Location of Microvilli Cilia and Stereocilia They are found in the small Flagella intestines, Basal Infoldings and kidneys, egg Hemidesmosomes cells, and white Cell Junctions blood cells. Blood Cells and Microvilli in small intestine Sex Cells 15  Specialized Cells and Cell Structures in Animals Microvilli Structure of Cilia Cilia and Stereocilia Flagella Basal Infoldings and Hemidesmosomes Cell Junctions A cilium’s structural core is made of nine pairs of Blood Cells and Sex Cells microtubules on the outside ring with 2 microtubules on the central portion. 16  Specialized Cells and Cell Structures in Animals Microvilli Function of Cilia Cilia and Stereocilia In the respiratory tract, cilia prevent Flagella mucus (from Basal Infoldings and goblet cells), Hemidesmosomes bacteria, and dirt Cell Junctions from entering the Cilia above the Blood Cells and lungs. pseudostratified Sex Cells epithelia of the trachea 17  Specialized Cells and Cell Structures in Animals Microvilli Function of Stereocilia Cilia and Stereocilia Flagella Basal Infoldings and Hemidesmosomes Cell Junctions Stereocilia in a frog’s inner ear allow it to detect sounds from its environment. Through these, frogs Blood Cells and Sex Cells have a mechanism to detect and escape from potential threats. 18  Specialized Cells and Cell Structures in Animals Microvilli Structure and Function of Flagella Cilia and Stereocilia Flagella are tail-like Flagella structures that Basal Infoldings and provide Flagella Hemidesmosomes motility to Cell Junctions cells. Blood Cells and Flagella of Euglena Sex Cells 19 How does the location of specialized structures in cells relate to their functions? 20  Specialized Cells and Cell Structures in Animals Microvilli Cilia and Stereocilia Basal infoldings and Flagella hemidesmosomes are both found at Basal Infoldings and Hemidesmosomes the basement membrane of Cell Junctions epithelial cells. Blood Cells and Sex Cells 21  Specialized Cells and Cell Structures in Animals Microvilli Cilia and Stereocilia Hemidesmosomes help the epithelial Flagella tissue provide protection and Basal Infoldings and Hemidesmosomes structural support to the underlying Cell Junctions cells. Blood Cells and Sex Cells 22  Specialized Cells and Cell Structures in Animals Microvilli Cilia and Stereocilia Basal infoldings are responsible Flagella for increasing Basal Infoldings and surface area and Hemidesmosomes for ion and fluid Cell Junctions transport. Basal infoldings in an excretory duct Blood Cells and Sex Cells 23  Specialized Cells and Cell Structures in Animals Microvilli Cilia and Stereocilia Flagella Basal Infoldings and Hemidesmosomes Cell Junctions Blood Cells and Sex Cells Cell junctions are found in epithelial cells and are mainly responsible for connecting adjacent cells. 24  Specialized Cells and Cell Structures in Animals Microvilli Cilia and Stereocilia Tight junctions prevent leakage Flagella of substances. Basal Infoldings and Hemidesmosomes Cell Junctions Blood Cells and Sex Cells 25  Specialized Cells and Cell Structures in Animals Microvilli Cilia and Stereocilia Flagella Adherens Basal Infoldings and junctions Hemidesmosomes connect Cell Junctions adjacent cells. Blood Cells and Sex Cells 26  Specialized Cells and Cell Structures in Animals Microvilli Cilia and Stereocilia Flagella Desmosomes Basal Infoldings and Hemidesmosomes connect adjacent cells. Cell Junctions Blood Cells and Sex Cells 27  Specialized Cells and Cell Structures in Animals Microvilli Cilia and Stereocilia Flagella Basal Infoldings and Gap junctions Hemidesmosomes serve as channels Cell Junctions of ions, water and Blood Cells and other essential Sex Cells substances. 28  Specialized Cells and Cell Structures in Animals Microvilli Cilia and Stereocilia Flagella Basal Infoldings and Hemidesmosomes Cell Junctions Red blood cells are biconcave to aid in the diffusion of Blood Cells and Sex Cells gases from the air sacs of the lungs and into the oxygen-deprived tissues of the rest of the body. 29  Specialized Cells and Cell Structures in Animals Microvilli Cilia and Stereocilia Flagella Basal Infoldings and Hemidesmosomes Cell Junctions The lack of nucleus in red blood cells gives more Blood Cells and Sex Cells space for hemoglobin. Thus, more oxygen molecules can be transported. 30  Specialized Cells and Cell Structures in Animals Microvilli Cilia and Stereocilia Flagella Basal Infoldings and Hemidesmosomes Cell Junctions Blood Cells and Red blood cells also lack mitochondria. They generate Sex Cells their energy through anaerobic respiration. 31  Specialized Cells and Cell Structures in Animals Microvilli White blood Cilia and Stereocilia cells are responsible for Flagella the body’s defenses. Basal Infoldings and Hemidesmosomes They can either Cell Junctions Types of white blood cells be granulocytes Blood Cells and or agranulocytes. Sex Cells 32  Specialized Cells and Cell Structures in Animals Microvilli Cilia and Stereocilia Egg cells are the largest cells in Flagella the human body and are Basal Infoldings and Hemidesmosomes necessary for sexual Cell Junctions Egg cells have two outer reproduction. membrane layers, namely, Blood Cells and zona pellucida and corona Sex Cells radiata. 33  Specialized Cells and Cell Structures in Animals Microvilli Cilia and Stereocilia Flagella Basal Infoldings and Hemidesmosomes Cell Junctions Sperm cells travel from the testes to the female’s Blood Cells and Sex Cells fallopian tube to facilitate an event called fertilization. 34 What are the specialized cells in plants? What makes them essential components of the plant? 35  Specialized Cells and Cell Structures in Plants Trichomes Root Hairs Mesophyll Cells Xylem and Phloem Trichomes on a sundew plant 36  Specialized Cells and Cell Structures in Plants Trichomes Structure and Function of Trichomes These are epidermal outgrowths Root Hairs responsible for ○ preventing insect attacks, Mesophyll Cells ○ shading leaves, and ○ trapping insects. Xylem and Phloem 37 How do trichomes differ from root hairs in terms of function? 38  Specialized Cells and Cell Structures in Plants Trichomes Root Hairs Mesophyll Cells Xylem and Phloem Lily plant’s root hairs 39  Specialized Cells and Cell Structures in Plants Trichomes Structure and Function of Root Hairs Root hairs are tiny hair-like structures Root Hairs that originated from the epidermis of plants. Mesophyll Cells Root hairs facilitate the absorption of Xylem and Phloem water from the substrate. 40  Specialized Cells and Cell Structures in Plants Trichomes Root Hairs Mesophyll Cells Xylem and Phloem Microscopic layers of a leaf 41  Specialized Cells and Cell Structures in Plants Trichomes Structure and Function of Mesophyll Mesophyll layer is primarily Root Hairs responsible for photosynthesis. Mesophyll Cells It is made up of palisade cells and spongy cells. Xylem and Phloem 42 How does the arrangement of cells in the mesophyll layer help in photosynthesis? 43  Specialized Cells and Cell Structures in Plants Trichomes Root Hairs Mesophyll Cells Xylem and Phloem Vascular bundle of Sparganium 44  Specialized Cells and Cell Structures in Plants Trichomes Function of Xylem and Phloem Xylem and phloem tissues consist of Root Hairs specialized cells that are responsible for transporting essential substances, Mesophyll Cells such as water, minerals, and food needed by the plants. Xylem and Phloem 45  Check Your Understanding Identify what is being described in each of the following items. 1. These are hairlike structures responsible for protecting plants from insect attacks. 2. It is the inner layer of leaves where photosynthesis happens. 3. The cells of this tissue transport water and minerals from the soil to different parts of the plant. 46  Check Your Understanding Determine the modified cells that need to function in the following situations and explain your answer. You may have more than one answer in each item. 1. Pathogenic bacteria enter the trachea of the respiratory tract. 2. An indoor plant starts to desiccate. 3. Insects start to feed on plants. 47  Let’s Sum It Up! Modified or specialized cells have developed structures that help them carry out their functions. Specialized cells in animals include the following: ○ Microvilli are responsible for increasing the surface area for absorption. ○ Cilia and stereocilia are responsible for movement and sensation, respectively. 48  Let’s Sum It Up! Specialized cells in animals include the following: ○ Flagella are responsible for locomotion or motility. ○ Basal infoldings and hemidesmosomes are responsible for fluid transport and attachment, respectively. ○ Cell junctions serve as connections between adjacent cells. 49  Let’s Sum It Up! Specialized cells in animals include the following: ○ Red and white blood cells are responsible for transporting oxygen and protecting the body from pathogens, respectively. ○ Sperm and egg cells aid in the reproduction process. 50  Let’s Sum It Up! Specialized cells in plants include the following: ○ Trichomes serve as protection of plants from extreme temperatures and insect or herbivore attacks. ○ Root hairs increase the surface area for the absorption of water. ○ Mesophyll cells serve as the sites of photosynthesis. 51  Let’s Sum It Up! Specialized cells in plants include the following: ○ Xylem and phloem consist of cells that are responsible for the transport of essential substances such as water and photosynthetic by-products. 52  Let’s Sum It Up! Animals and plants have specialized cells and cell structures that ultimately contribute to the growth, development, and survival of the organism. 53 Challenge Yourself Microvillus atrophy is a congenital disease characterized by a lack of microvilli in the intestines. What are the possible effects of this disease in newborn babies? 54 Photo Credits Slide 2: Wooden Tile Talent Image by Nick Youngson is licensed under CC BY-SA 3.0 via The Blue Diamond Gallery. Slide 3: Clownfish in Andaman Coral Reef by Ritiks is licensed under CC BY-SA 3.0 via Wikimedia Commons. Slide 15: Normal Small Intestine Mucosa by Ed Uthman is licensed under CC BY 2.0 via Flickr. Slide 19: Euglena gracilis by naturalismus is licensed under CC BY-SA 2.0 via Flickr. Slide 36: Trichomes by incidencematrix is licensed under CC BY 2.0 via Flickr. 55 Bibliography Campbell, Neil A. Biology. Frenchs Forest, N.S.W.: Pearson Benjamin Cummings, 2008. Cui, Dongmei. Atlas of Histology with Functional and Clinical Correlations. 351 West Camden Street, Baltimore. Lippincott Williams and Wilkins, 2011. Mader, Sylvia S., Michael Windelspecht, and Sylvia S. Mader. Introductory Biology. United States: McGraw-Hill Create, 2014. Miller, Kenneth R., and Joseph S. Levine. Prentice-Hall Biology. Upper Saddle River, NJ: Pearson Prentice Hall, 2006. Sabile, Mary Jane G., General Biology 1. Quezon City, Philippines: Phoenix Publishing House, Inc., 2018. 56