Science Reviewer PDF

NAME: YURI ANAIAH O. DE VENECIA 9 – STE HAWKING SCIENCE REVIEWER Breathing - is the process that delivers oxygen to where it is needed in the body and removes carbon dioxide. All animals need oxygen to live. Land animals get oxygen from the air. Air flows into your body th...

NAME: YURI ANAIAH O. DE VENECIA 9 – STE HAWKING SCIENCE REVIEWER Breathing - is the process that delivers oxygen to where it is needed in the body and removes carbon dioxide. All animals need oxygen to live. Land animals get oxygen from the air. Air flows into your body through the nose or mouth and enters a specific pathway for air. Nose and Mouth (Nasal Cavity) - The nose is what we normally use to inhale and exhale. It has two holes called nostrils through which air passes. passes. The skin lining both nostrils is embedded with tiny hairs called cilia. The mouth is what we use to breathe when we need more air than what can be taken in through the nostrils, as when we pant or puff when we are exhausted. Pharynx and Larynx - The pharynx is the opening just behind the nose and mouth and is part of both the respiratory and digestive systems. Both food and air pass through the pharynx; it is lined with tissues called tonsils which can partially obstruct the passage of either of the two. Like when swallowing, respiration is interrupted. The pharynx ends in the esophagus and the larynx. The larynx is also known as the "voice box" because it houses the vocal cords and the different muscles used in producing sounds. The epiglottis, a cartilage found at the top of the larynx, aids in closing it tightly to prevent the passage of food or liquids. Trachea and Bronchi - The trachea, also referred to as the windpipe, is a tube through which respiratory gas transport takes place. It is lined with ciliated cells to push particles out, and cartilage rings to guard it against pressure when breathing. The end of the trachea is split into two tubes called the bronchi, which also have several thin- walled branches called bronchioles. These bronchioles lead to air sacs called alveoli, where most of the gas exchange happens. Lungs - The lungs are the most essential organ for respiration. They consist of a cluster of bronchioles and alveoli, blood vessels, and elastic tissue. Their main function is to transfer oxygen into the bloodstream and to excrete carbon dioxide into the air. Inhalation (inspiration) and exhalation (expiration) are the processes by which the body takes in oxygen and expels carbon dioxide during breathing. You breathe with the help of the diaphragm and the intercostal muscles between your ribs. The diaphragm is shaped like a parachute and located below your lungs. It divides the chest cavity from the abdomen, while intercostal muscles are located between your ribs. Breathing in (Inhalation) - When you breathe in (inhale), your diaphragm contracts (tightens) and moves downward. In this way, it could provide a bigger space for your lungs to expand in the chest cavity. As your lungs expand, air enters the nose and mouth, traveling towards your windpipe and into your lungs. Breathing out (Exhalation) - When you breathe out (exhale), your diaphragm relaxes and moves upward into the chest cavity. The function of the circulatory system is to transport oxygen and nutrients to the body cells and to carry deoxygenated (oxygen-poor) blood and carbon dioxide back to the heart and lungs. Its major parts are the heart, the blood, and the blood vessels. The heart is a muscular pump that keeps the blood flowing to each part of the body. The blood circulates through a closed system—that is, blood in the circulatory system stays inside the vessels. Generally, your blood circulates from your heart, throughout your body, and back to your heart about every 60 seconds. Blood is a tissue made of fluid, cells, and fragments of cells. The fluid or the flowing portion of the blood is termed plasma. Plasma is a straw-colored fluid and makes up about 55 percent of the total volume of blood. Red and white blood cells and platelets are suspended in plasma. Arteries - carry blood away from the heart towards the rest of the body. They carry oxygenated (oxygen-rich) blood except for pulmonary arteries, which carry deoxygenated blood to the lungs for oxygenation. Veins - carry blood from the rest of the body back towards the heart. They carry deoxygenated (oxygen-poor) blood excluding pulmonary veins, which carry oxygenated blood from the lungs to the heart. Capillaries - are the smallest blood vessels that move blood to and from the cells of the body. These vessels are so small that blood cells must move through them in a single file. Its walls are very thin and materials can easily diffuse into and out of them. The main function of the heart is to keep blood moving constantly through the body. The two smaller chambers are the right atrium and left atrium (plural, atria). The ventricles are separated by a thick wall of tissue called septum and the two larger chambers are the right and left ventricles. Pulmonary Circulation - occurs only between the heart and the lungs. Systemic Circulation - occurs between the heart and the rest of the body, except for the lungs. Coronary Circulation - consists of the blood vessels that supply blood to, and remove blood from, the heart. Gene a small section of a chromosome that describes a particular characteristic such as skin or eye color, hair structure, and height. In genetics, this is also known as the "allele". DNA (Deoxyribonucleic acid) is a chemical molecule formed from a smaller biomolecule called nucleotides. DNA has 4 different types of nucleotides on the basis of specific nitrogenous bases such as adenine (A), guanine (G), cytosine (C), and thymine (T). Respiratory System Air enters your body through the nose or mouth, moves down your throat & passes through the trachea or windpipe, then to your lungs. The diaphragm is a muscle that tightens and relaxes to make you breathe in and out. Your diaphragm lies below the lungs. Oxygen is taken into your blood and carbon dioxide leaves your blood through small tubes called bronchi and then tiny air sacs called alveoli. Circulatory System Carries oxygen, nutrients & waste throughout the body. Made up of the heart, blood vessels, and blood The heart is the center of this system, it pumps blood through blood vessels called arteries. The heart is also called the cardiovascular muscle. Blood moves from arteries to capillaries. In the capillaries oxygen & nutrients move from the blood to the body’s cells. Blood then moves through veins back to the heart, carrying carbon dioxide in it. The circulatory system has three types of blood vessels: arteries, veins, and capillaries. Arteries carry blood away from the heart towards the rest of the body. Veins carry blood from the rest of the body back towards the heart. Capillaries are the smallest blood vessels that move blood to and from the cells of the body. Homozygous: An individual with two identical forms of a gene, results in true breeding for a characteristic Heterozygous: An individual with two different forms of a specific gene, one from each parent An autosome is a non-sex chromosome that is the same in both sexes of a species. Non-autosomal chromosomes are usually referred to as sex chromosomes, allosomes, or heterosomes. A Diploid is a cell or organism that has paired chromosomes, one from each parent. In humans, cells other than human sex cells, are diploid and have 23 pairs of chromosomes. Human sex cells (egg and sperm cells) contain a single set of chromosomes and are known as haploid. Homogametic- two of the same chromosomes like the human female sex chromosome, XX Heterogametic- two different chromosomes as the human male sex chromosomes, XY. Sex-linked genes are genes that are present on the X or Y chromosomes. Sex linkage is the phenotypic expression of an allele that is related to the chromosomal sex of an individual. Examples of X-linked Recessive Disorders - red/green color blindness - Hemophilia - Other examples: Deuteranopia, Protanopia Hemophilia A, Hemophilia B, Fragile-X Syndrome, G6PD Deficiency, and Duchenne Muscular Dystrophy. An Ishihara color test plate. With properly configured computer displays, people with normal vision should see the number "74". Many people who are color blind see it as "71", and those with total color blindness may not see any numbers. Y-linked Recessive Disorders located in Y chromosomes are called Y-linked genes or Holandric traits. The passing of traits is always from father to son and not to daughter. Hypertrichosis pinnae Auris trait characterized by hairy ears. Retinitis pigmentosa is a rare eye disorder characterized by the loss of vision over time this condition affects the retina to respond to light. Sex-Limited Traits these traits are autosomal which means that they are not found on the X and Y chromosomes. The expression of the genes in the phenotype is exclusive only to one gender which is commonly secondary sex characters. Sex-influenced traits their genes are not carried on the sex chromosomes, they are expressed phenotypically. The difference is in the ways the two genders (male and female) express the genes.