Cell Diversity.docx

Cell Diversity Tissues A tissue is a group of similar cells that carry out a common function. Tissue types vary between plants and animals. There are four basic types of animal tissue, including; **Know one Animal and one plant tissue** Animal tissue - Connective tissue: Connective tissue supports o...

Cell Diversity Tissues A tissue is a group of similar cells that carry out a common function. Tissue types vary between plants and animals. There are four basic types of animal tissue, including; **Know one Animal and one plant tissue** Animal tissue - Connective tissue: Connective tissue supports other tissues and binds them together. Blood, cartilage, bone, lymph and adipose are examples of connective tissue. Collagen is the most abundant protein found in connective tissue, and it can make up to one third of the protein in a body. It is found in skin, tendon, bone, and cartilage, giving them strength and flexibility. (1) Plant Tissue - Meristematic tissue: Rapidly diving tissue and is often referred to as cambium. The function of cambium is to produce new cells to enable the plant to grow in both length and width. It is found at the tip of the roots and shoots and in buds, which are condensed stems. It is also found in vascular bundles between the xylem and phloem and in woody plants, forming a layer outside the phloem. It can be identified as it forms layers of parallel cells increasing in size from the midline outwards. (2) Tissue Culture Tissue culture is the growth of cells in a sterile nutrient medium outside the organism. When cells are grown outside the body, it is imperative that they and the medium in which they are grown are both sterile to ensure that no pathogens are transmitted to the recipient. The medium must contain nutrients to provide the growing cells with food to supply energy and the raw materials they need to grow properly. Applications **Know 2** - Skin Epidermis for grafts - Growing human cells for cancer research - Micropropagation of plant cells - Stem cell research Organs An organ is a group of tissues carrying out a common function. Organs are specialised to carry out specific functions. Examples of organs include; Animal Organs **Know one** - Heart: Pumps blood to the lungs and collects blood from the lungs. This is called the pulmonary circuit. - Lungs: Remove CO2 from the blood and supply O2 to the blood - Brain: Receives information about the environment and processes it, decides on the course of action, and initiates the action. Consciousness and emotion reside in the brain Plant Organs **Know One** - Stamen: Consists of the anther and filament tissues - Carpel: Consists of stigma, style, and ovary tissues - Leaves - Stems - Roots Organ Systems An organ system is a group of organs carrying out a particular function Examples **Know two** - Breathing system: Consists of the nose, mouth, trachea, bronchi, bronchioles, alveoli, lungs, diaphragm, and ribs. They all work together to supply oxygen to the lungs and remove carbon dioxide and water from the blood. - Reproductive system: Male reproductive system consists of the testes, epididymis, sperm ducts, seminal vesicles, prostate, urethra, and penis. Female reproductive system consists of the ovaries, fallopian tubes, uterus, vagina, and the external genitalia Exam Questions 2010 – HL – Section A – Question 4 4. (a) What is a tissue? Group of similar cells with a common function (b) Name a tissue found in plants – Meristematic tissue (c) Give a function of the tissue referred to in part (b) – For growth (d) Name a tissue found in animals - Muscle (e) Give a function of the tissue referred to in part (d) – For movement (f) Explain what is meant by the term tissue culture – Cells grown in or own a culture medium (g) Give one application of tissue culture – Cancer Research References Courses.lumenlearning.com Byjus.com