SCIENCE REVIEWER (1).pdf

SCIENCE REVIEWER >The Respiratory System ❖ Breathing The process that delivers oxygen to where it is needed in the body and removes carbon dioxide. We breathe in to allow oxygen to move into our bloodstream and we...

SCIENCE REVIEWER >The Respiratory System ❖ Breathing The process that delivers oxygen to where it is needed in the body and removes carbon dioxide. We breathe in to allow oxygen to move into our bloodstream and we breathe out to remove carbon dioxide from our blood. The oxygen is carried in the blood to all cells of the body. The air we breathe out has 100 times more carbon dioxide than the oxygen we breathe in. ❖ Parts and Its Functions Nose and Mouth (Nasal Cavity) Nose - what we normally use to inhale and exhale. It has two holes called nostrils through which air passes. ↪ Cilia - The tiny hairs that line the inside of the nostrils and act like a filter to catch dust and other small particles in the air we breathe. Mouth - what we use to breathe when we need more air than what can be taken in through the nostrils. Pharynx and Larynx Pharynx Opening just behind the nose and mouth Part of both the respiratory and digestive systems. Both food and air pass through the pharynx which is lined with tissues called tonsils which can partially obstruct the passage of either of the two. Ends in the esophagus and the larynx. Larynx("Voice box") Houses the vocal chords 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 Trachea(“The windpipe”) where respiratory gas transport takes place. 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.  Bronchi Two tubes at the end of the trachea Bronchioles Thin-walled branches Alveoli where most of the gas exchange happens. Lungs The most essential organ for respiration. They consist of a cluster of bronchioles and alveoli, blood vessels, and elastic tissue. Main function: transfer oxygen into the bloodstream, and excrete carbon dioxide into the air. ❖ Mechanism of Breathing Inhalation (inspiration) & exhalation (expiration) 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. Diaphragm shaped like a parachute and located below your lungs. Divides the chest cavity from the abdomen, while intercostal muscles are located between your ribs. Breathing in (Inhalation) Diaphragm contracts (tightens) and moves downward. They contract to pull your rib cage both upward and outward when you breathe. As your lungs expand, air enters the nose and mouth, traveling towards your windpipe and into your lungs. Breathing out (Exhalation) Diaphragm relaxes and moves upward into the chest cavity. The intercostal muscles also relax to decrease the area in the chest cavity. As the space in the chest cavity is reduced, carbon dioxide is pushed out of your lungs and windpipe, and then out of your nose or mouth. >The Circulatory System Heart A muscular pump that keeps the blood flowing to each part of the body. “Cardiovascular muscle” Blood  Circulates through a closed system. Blood in the circulatory system stays inside the vessels. Circulates from your heart, throughout your body, and back to your heart about every 60 seconds. Tissues are made of fluid, cells, and fragments of cells. The fluid or the flowing portion of the blood is termed plasma. Plasma 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 Pulmonary Arteries 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 Carry oxygenated blood from the lungs to the heart. Capillaries 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. Main function: 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. Types of Circulation: 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. >Genetic Information & Non-Mendelian Inheritance Nucleus The control center of the cell. Inside the nucleus are the genetic information chromosomes, genes, and DNA. Chromosomes Made up of compacted genes, genes are made from DNA DNA(Deoxyribonucleic acid) Made up of nucleotides  Genetic materials are arranged from largest to smallest unit, from chromosomes, and genes to DNA. A chemical molecule is formed from a smaller biomolecule called nucleotides. DNA has 4 different types of nucleotides based on specific nitrogenous bases such as adenine (A), guanine (G), cytosine (C), and thymine (T). Gene Small section of a chromosome that describes a particular characteristic such as skin or eye color, hair structure, and height. Also known as the "allele". 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 >Mendelian and Non-Mendelian Genetics >Sex-Linked Traits Autosome Non-sex chromosomes the same in both sexes of a species. Non-autosomal chromosomes  Sex chromosomes, allosomes, or heterosomes. Diploid is A cell or organism that has paired chromosomes, one from each parent. 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 as the human female sex chromosome, XX. Heterogametic Two different chromosomes as the human male sex chromosomes, XY. Sex-linked genes Genes that are present on the X or Y chromosomes. Sex linkage The phenotypic expression of an allele that is related to the chromosomal sex of an individual. 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. Y-linked Recessive Disorders Located in Y chromosomes 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 Autosomal(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 Not carried on the sex chromosomes Expressed phenotypically. The difference is in the ways the two genders (male and female) express the genes. >Photosynthesis PHOTO = light SYNTHESIS = to make whole or put all the parts together.  Photosynthesis ○ The process whereby plants, algae, and some bacteria, use the energy of the sun to synthesize organic compounds (sugars) from inorganic compounds (CO2 and water). ATP(Adenosine Triphosphate) a molecule that carries energy within cells NADPH(Nicotinamide Adenine Dinucleotide Phosphate Hydrogen) an energy-carrying molecule produced in the first stage of photosynthesis >Biodiversity & Evolution DEFINITION of TERMS Biodiversity - the different varieties of life found in certain areas.  Biodiversity index - a mathematical measure of species diversity in a certain community. Population - the total number of organisms living together in a particular area or composed of interbreeding members of the same species. Population density - the average number of individuals in a population per unit of area. Carrying capacity - maximum population size of an environment that can support life. Endangered species - when an animal or plant becomes low in population because of human interventions. Extinction - the population of animals and plants is being lost in the community. Environmental issues - problems encountered by the community. Pollution - the contamination of air, water, and soil Diversity Index (DI) = number of species in the area/total number of individuals in the area The range is from 0 to 1, where: High scores (close to 1) indicate high diversity Low scores (close to 0) indicate low diversity Population Density = Number of Individuals / Size of an Area Threats to Biodiversity: