GEN-BIOLOGY-REVIEWER PDF

CELL THEORY · Cell is the basic unit of all living organisms · It is the smallest structure that is able to carry out the basic functions of life · All living organisms are composed of one or more cells · All cells come from pre-existing cells ZYGOTE · a fertilized egg from union of egg cell and sp...

CELL THEORY · Cell is the basic unit of all living organisms · It is the smallest structure that is able to carry out the basic functions of life · All living organisms are composed of one or more cells · All cells come from pre-existing cells ZYGOTE · a fertilized egg from union of egg cell and sperm cell Levels of Organization Cells > Tissues > Organ > Organ System > Organism CELL THEORY Hans and Zacharias Janssen - inventor of the first optical microscope Anton Van Leeuwenhoek - discovered bacteria and called it animalcules. Animalcules is an old term for microscopic organisms that included bacteria, protozoans and very small animals. Robert Hooke - experimented on a piece of cork specimen which appear as tiny compartments similar to small room. He coined the word “cell” to describe these chamber-like structures. Matthias Schleiden - discovered that all plants are made of cells Theodore Schwann - discovered that all animals are made of cells Rudolf Virchow - discovered that all cells come from pre-existing cells. “Omnis cellula e cellula” means “all cells come from cells; every cell is born of a previous cell, which was born of a previous cell” Francesco Redi - italian physician who discovered the ”Theory of Spontaneous Generation or Abiogenesis” which states that living organisms originated from non-living matters. Lazzaro Spallanzani - performance experiment on soup in sealed containers and proved the microorganisms that spoil the soup were airborne. Louis Pasteur - french chemist and microbiologist renowned for his discoveries of the principles of vaccination, microbial fermentation, and pasteurization. CELL STRUCTURE CELL TYPES Living organisms based on the presence of nucleus in their cells are classified as prokaryotes and eukaryotes PROKARYOTES - no definite nucleus EUKARYOTES - have nucleus Cell structures can only be seen under high magnification electron microscope. It is separated internally into numerous little organs called organelles HUMAN TISSUE Connective Tissue, Epithelial Tissue, Nervous Tissue, Muscle Tissue EPITHELIAL TISSUE Covers the body surface and lines cavities Its function includes lining, protecting, and forming glands. (Saliva & Sweat) Skin as an organ is made of tissue called Epithelial Tissue It is present on our akin and inside of respiratory and digestive system Things we must keep in mind - Cells are tightly packed - Continuous sheet of cells - Contagion no blood cells Types of Epithelial Tissue 1. Number layer of cell - Simple epithelial tissue (1 layer of cell only) - Stratified epithelial tissue (multiple layer of cell) 2. Shape of the cells - Squamous epithelium (floor-like tile) - Cuboidal epithelium (ice cubes) - Columnar epithelium (rectangular column) SQUAMOUS - Simple squamous single layer > transport oxygen to blood > lungs - Stratified squamous many layers > protection > skin CUBOIDAL - Simple cuboidal single layer > filters out blood for toxic substances > kidney - Stratified cuboidal two layers > protect the duct from damage - duct/tube glands > sweat, salivary, tear gland COLUMNAR - Simple columnar organs to DS > protection > impermeable barrier against any bacteria - Pseudo stratified columnar lines the uterus > uterus > absorption and secretion of mucus, protection from foreign particles (dust, pathogens, and allergens), and transport of materials such as hormones and enzymes. Cells with special features ✓ Ciliated epithelium - helps in smooth movement of particles ✓ Keratinized epithelium - makes skin water proof Columnar and cuboidal epithelium are hair like filaments called Cilia Stratified epithelial cells are never ciliated CONNECTIVE TISSUE Helps to connect all the organs and parts of the body An adult human body has 206 bones Specialized connective tissue Bones are connected type of tissue - Supports and hold our internal organ together - Bone cells or osteocytes (calcium & phosphorus) BLOOD - a type of fluid connective tissue (RBC, WBC, PLATELETE) BINDING Dense Connective Tissue Ligament - connects 2 bones Tendon - connects muscle to the bone PACKING Areolar/Loose Connective Tissue Filler tissue in hollow organs. The skin is connected to our muscle SUPPORTING Skeletal Connective Tissue Bone - framework of the body Cartilage - slightly elastic parts - widely spaced and the matrix is cheese like firm and elastic Adipose Tissue Acts as an insulator & shock absorber Fluid Connective Tissue Helps in oxygen transport MUSCULAR TISSUE Facilitated movements of the animal by contraction of individual muscle cells 17 muscles to smile 43 muscles to frown Muscle = movement Special proteins like ACTIN & MYOSIN SKELETAL MUSCLE - voluntary movement - attached to our skeleton - never endings - voluntary muscles - controlled consciously SMOOTH MUSCLE - involuntary movement - breathing, secretion, ejaculation, birth, and other reflexes - involuntary muscles CARDIAC MUSCLE - involuntary movement - works to keep heart pumping NERVOUS TISSUE Brain makes all decisions at a speed of 268 miles per hour Spinal cord is the only way through which the rest of our body is connected to our brain. It regulated and decides the necessary actions to be carried out Brain and spinal cord are centrally located Nerves - Nerve fiber (long, strand like fibers) - Nerve impulse (messages or signals) Neurons or nerves - Transmit electrical impulses Nerve cell body - Axon (away) - Dendrite (towards) HUMAN ORGAN SYSTEM INTEGUMENTARY SYSTEM - Skin, hair, nails, glands, and nerves - Acts as barrier to protect the body from outside world - Retain body fluids, protect against disease, eliminate waste products, and regulates body temperature Skin is composed of three layers of tissue : EPIDERMIS - The outer or top layer - Keeping your skin hydrated - Made of stratified squamous - Produce new skin epithelium - Determines skin color - Protects the body from outside world DERMIS - The middle - Made of fibrous connective tissue - Protects body from harm - Supports the epidermis - Reason of sensation - Produces sweat and hair HYPODERMIS - the inner subcutaneous or bottom layer - Made of adipose tissue and loose connective tissue - Storing energy - Connecting the dermis layer of skin to muscles and bones 3 major cell in our akin KERATINOCYTES - Produces keratin for strength and flexibility MELANOCYTES - Produces melanin, brown or black color pigment, provides skin color, protects skin from uv rays LANGERHANS - Helps to protect skin by keeping out dangerous substances from entering your body MUSCULAR SYSTEM Movement Has the ability to contract and move the other parts of the body 4 characteristics of muscles EXTENSIBILITY ELASTICITY EXCITABILITY CONTRACTILITY SKELETAL SYSTEM To form solid framework  Supports and protects the body's organs and anchors skeletal system Axial Skeleton - protects internal organ Appendicular Skeleton - provide support and flexibility at joints Function of skeletal system Framework, protection, storage of nutrients, produce blood, control movements RESPIRATORY SYSTEM Responsible for taking in oxygen and expelling carbon dioxide a. External respiration - breathing process, involves inhalation and exhalation of gases. b. Internal respiration - involves gas exchange between the blood and the body cells c. Cellular respiration - involves conversion of food (oxygen and other nutrients) to energy DIGESTIVE SYSTEM The digestive system is responsible for taking whole foods and turning them into energy and nutrients to allow the body to function, grow, and repair it. Ingestion of food Secretion of fluids and digestive enzymes (saliva, mucus, hydrochloric acid, enzymes, bile) Mixing and movement of food and wastes through the body Digestion of food into smaller pieces Absorption of nutrients Excretion of solid wastes EXCRETORY SYSTEM/URINARY SYSTEM The body takes nutrients from food and converts them to energy. 1. MAINTAIN OSMOTIC BALANCE 2. REMOVE METABOLIC WASTE NERVOUS SYSTEM The nervous system consists of the brain, spinal cord, sensory organs, and all of the nerves that connect these organs with the rest of the body; these organs are responsible for the control of the body and communication parts CENTRAL NERVOUS SYSTEM (CNS) Consisting of the brain and spinal cord where information is evaluated and decisions made PERIPHERAL NERVOUS SYSTEM (PNS) Sensory nerves and sense organs of the peripheral nervous system (PNS) monitor conditions inside and outside of the body and send this information to the CNS ANS (autonomic) - Sympathetic - Parasympathetic SNS (sonomatic) ENDOCRINE SYSTEM Responsible for the hormones that controls the moods, growth and development, metabolism, organs, and reproduction. Controls how these hormones are released and sends those hormones into the bloodstream to other body parts LYMPHATIC SYSTEM A network of tissues and organs that help rid the body of toxins, waste, and other unwanted materials. The primary function of the lymphatic system is to transport lymph, a fluid containing infection-fighting white blood cells, throughout the body. CIRCULATORY SYSTEM A vast network of organs and blood vessels 2 Independent network 1. Pulmonary system - providing fresh oxygen and removing carbon dioxide 2. Systemic system - provides functional blood supply to all body tissue The way blood flows in the human body is unique, and it is quite efficient too. The blood circulates through the heart twice; hence, it is called double circulation The main advantage of double circulation is that every tissue in the body has a steady supply of oxygenated blood, and it does not get mixed with the deoxygenated blood. HUMAN REPRODUCTIVE SYSTEM Is a collection of internal and external organs in both males and females that work together for reproduction. The male reproductive system is different from the female reproductive system, both in structure and in function. Male Reproductive System The male gametes, i.e., sperms are produced within the male reproductive system. Sperms are small unicellular structures with a head, middle piece, and a tail. Female Reproductive System 1. Production of female gametes is called ovum/egg.  2. Providing nutrition and protecting the developing embryo. During puberty, eggs in the ovaries start to mature. e ovaries releases the matured ovum in every 28 to 30 days is called ovulation.