Biology Revision for "O" level examinations

CSEC BIOLOGY- PAPER ONE (January 2020)

What is the Endocrine system? It is a collection of  glands  that secrete  chemical messages  called hormones. Gland: A  gland  is a group of cells that produces and secretes, or gives off, chemicals. Hormone: are chemicals that regulate or controls the activity of certain cells or organs The nervous system sends electrical messages to control and coordinate the body. The endocrine system has a similar job, but uses chemicals to “communicate” Endocrine system works more slowly than the Nervous system Hormones are released from glands/cells into the blood vessels They travel to target organs, where they cause a change  Endocrine vs Nervous system The nervous system sends electrical messages to control and coordinate the body. The endocrine system has a similar job, but uses chemicals to “communicate” Endocrine system works more slowly than the Nervous system Response of Nervous system is short lived, while response of Endocrine system...

Types of joints 1.       Movable joints      The bones of these joints are separated by a pad of flexible cartilage. There are two type of movable joints: a.        Slightly movable joints: -are found adjacent between adjacent vertebrae. The cartilage between the joints (called intervertebral disc) absorbs shock. They can be displaced due to injury. Other e.g. Pivot joints: between neck and cranium. b.       Synovial joints: the bones are held together by ligaments and are separated by synovial fluid. The fluid lubricates the joints, preventing the joints and cartilage caps of the bone from rubbing against each other. e.g. hinge joints: elbow, and knee         ball and socket: at shoulder and hips 2.       Immovable joints       These joints are held firmly in position by fibers. They exist betwee...

What is H1N1 flu? H1N1 is a flu virus. When it was first detected in 2009, it was called “swine flu” because the virus was similar to those found in pigs. The H1N1 or swine  flu  is a respiratory disease caused by  influenza   viruses  that infect the respiratory tract of pigs and result in a barking  cough ,  decreased appetite , nasal secretions, and listless behavior; the virus can be transmitted to humans. The H1N1 virus is currently a seasonal flu virus found in humans. Although it also circulates in pigs,  you cannot get it by eating properly handled and cooked pork or pork products Transmission Swine flu is transmitted from person to person by  inhalation  or ingestion of droplets containing virus from people  sneezing  or  coughing . Symptoms Symptoms of H1N1 Symptoms of swine flu are similar to most influenza infections. Some symptoms are listed below:    Fever (100 0...

Biotechnology  is the application of biological organisms, systems, or processes by various industries to help in the improvement of the value of materials and organism such pharmaceuticals, crops, and livestock (ASC-Chemistry for life). Biotechnology is not a new concept. It can be dated back to more than 6000 years ago (Biotechnology Industry Taken from:  unidigest.com Organization) when man first began to breed and domesticate plants and animals. However, modern biotechnology involves more genetic engineering, where an organism's genome is altered. Because of this technology, Biotechnology may allow man to reshape the future of his planet. We may very well be able to reduce the imminent threat global climate change by modifying organisms so that they are better adapted to survive in their ecosystems, and improve quality of agricultural crops and livestock. With Genetic engineering, we may even be able to extend our lives, either by improving our diet and health care, ...