Saturday, March 21, 2020

Thirteen Rules of Basketball - James Naismith

Thirteen Rules of Basketball - James Naismith Basketball is an original American game invented by Dr. James Naismith in 1891. He designed it with rules of its own. These are the rules published in January 1892 in the school newspaper where he instituted the game. The rules set out a game that is a non-contact sport played indoors. They are familiar enough that those who enjoy basketball over 100 years later will recognize it as the same sport. While there are other, newer rules, these still form the heart of the game. Original 13 Rules of Basketball by James Naismith 1. The ball may be thrown in any direction with one or both hands.Current rule: This is still a current rule, except that now the team isnt allowed to pass it back over the midcourt line once they have taken it over that line. 2. The ball may be batted in any direction with one or both hands, but never with the fist.Current rule: This is still a current rule. 3. A player cannot run with the ball. The player must throw it from the spot on which he catches it, allowance to be made for a man running at good speed.Current rule: Players can dribble the ball with one hand as they run or pass, but they cant run with the ball when catching a pass. 4.  The ball must be held by the hands. The arms or body must not be used for holding it.Current rule: Still applies, it would be a traveling violation. 5.  No shouldering, holding, pushing, striking or tripping in any way of an opponent. The first infringement of this rule by any person shall count as a foul; the second shall disqualify him until the next goal is made or, if there was evident intent to injure the person, for the whole of the game. No substitution shall be allowed.Current rule: These actions are fouls and a player may be disqualified with five or six fouls or get an ejection or suspension with a flagrant foul. 6.  A foul is striking at the ball with the fist, violations of Rules 3 and 4 and such as described in Rule 5.Current rule: Still applies. 7.  If either side makes three consecutive fouls it shall count as a goal for the opponents (consecutive means without the opponents in the meantime making a foul).Current rule: Instead of an automatic goal, sufficient team fouls (five in a quarter for NBA play) now award bonus free throws attempts to the opposing team. 8.  A goal shall be made when the ball is thrown or batted from the grounds into the basket and stays there, providing those defending the goal do no touch or disturb the goal. If the ball rests on the edges, and the opponent moves the basket, it shall count as a goal.Current rule: In the original game, the basket was a basket and not a hoop with a net. This rule evolved into the goaltending and defense pass interference rules. Defenders cant touch the rim of the hoop once the ball has been shot. 9.  When the ball goes out of bounds, it shall be thrown into the field and played by the first person touching it. In case of dispute the umpire shall throw it straight into the field. The thrower-in is allowed five seconds. If he holds it longer, it shall go to the opponent. If any side persists in delaying the game, the umpire shall call a foul on them.Current rule: The ball is now thrown in by a player from the opposite team of the player who last touched it before it went out of bounds. The 5-second rule is still operative. 10. The umpire shall be the judge of the men and shall note the fouls and notify the referee when three consecutive fouls have been made. He shall have the power to disqualify men according to Rule 5.Current rule: In NBA basketball, there are three referees. 11.  The referee shall be the judge of the ball and shall decide when the ball is in play, in bounds, to which side it belongs, and shall keep the time. He shall decide when a goal has been made and keep account of the goals, with any other duties that are usually performed by a referee.Current rule: Timekeepers and scorekeepers now do some of these tasks, while the referee determines ball possession. 12. The time shall be two fifteen-minute halves, with five minutes rest between.Current rule: This varies by the level of play, such as high school and collegiate. In the NBA, there are four quarters, each 12 minutes long, with a 15-minute halftime break. 13. The side making the most goals in that time shall be declared the winner.  Current: The winner is now decided by points. In the NBA, five-minute overtime periods are played in case of a tie at the end of the fourth quarter, with the point total at the end determining the winner. If still tied, they play another overtime period. More: The History of Basketball and Dr. James Naismith

Wednesday, March 4, 2020

Cytoplasm - Definition and Function

Cytoplasm - Definition and Function Cytoplasm consists of all of the contents outside of the nucleus and enclosed within the cell membrane of a cell. It is clear in color and has a gel-like appearance. Cytoplasm is composed mainly of water but also contains enzymes, salts, organelles, and various organic molecules. Cytoplasm Functions The cytoplasm functions to support and suspend organelles and cellular molecules. Many cellular processes also occur in the cytoplasm. Some of these processes include protein synthesis, the first stage of cellular respiration (known as glycolysis), mitosis, and meiosis. In addition, the cytoplasm helps to move materials, such as hormones, around the cell and also dissolves cellular waste. Divisions The cytoplasm can be divided into two primary parts: the endoplasm (endo-,-plasm) and ectoplasm (ecto-,-plasm). The endoplasm is the central area of the cytoplasm that contains the organelles. The ectoplasm is the more gel-like peripheral portion of the cytoplasm of a cell. Components Prokaryotic cells, such as bacteria and archaeans, do not have a membrane-bound nucleus. In these cells, the cytoplasm consists of all of the contents of the cell inside the plasma membrane. In eukaryotic cells, such as plant and animal cells, the cytoplasm consists of three main components. They are the cytosol, organelles, and various particles and granules called cytoplasmic inclusions. Cytosol: The cytosol is the semis of organelles include mitochondria, ribosomes, nucleus, lysosomes, chloroplasts, endoplasmic reticulum, and Golgi apparatus. Also located within the cytoplasm is the cytoskeleton, a network of fibers that help the cell maintain its shape and provide support for organelles.Cytoplasmic Inclusions: Cytoplasmic inclusions are particles that are temporarily suspended in the cytoplasm. Inclusions consist of macromolecules and granules. Three types of inclusions found in the cytoplasm are secretory inclusions, nutritive inclusions, and pigment granules. Examples of secretory inclusions are proteins, enzymes, and acids. Glycogen (glucose storage molecule) and lipids are examples of nutritive inclusions. Melanin found in skin cells is an example of a pigment granule inclusion. Cytoplasmic Streaming Cytoplasmic streaming, or cyclosis, is a process by which substances are circulated within a cell. Cytoplasmic streaming occurs in a number of cell types including plant cells, amoeba, protozoa, and fungi. Cytoplasmic movement may be influenced by several factors including the presence of certain chemicals, hormones, or changes in light or temperature. Plants employ cyclosis to shuttle chloroplasts to areas receiving the most available sunlight. Chloroplasts are the plant organelles responsible for photosynthesis and require light for the process. In protists, such as amoeba and slime molds, cytoplasmic streaming is used for locomotion. Temporary extensions of the cytoplasm known as pseudopodia are generated that are valuable for movement and capturing food. Cytoplasmic streaming is also required for cell division as the cytoplasm must be distributed among daughter cells formed in mitosis and meiosis. Cell Membrane The cell membrane or plasma membrane is the structure that keeps cytoplasm from spilling out of a cell. This membrane is composed of phospholipids, which form a lipid bilayer that separates the contents of a cell from the extracellular fluid. The lipid bilayer is semi-permeable, meaning that only certain molecules are able to diffuse across the membrane to enter or exit the cell. Extracellular fluid, proteins, lipids, and other molecules may be added to a cells cytoplasm by endocytosis. In this process, molecules and extracellular fluid are internalized as the membrane turns inward forming a vesicle. The vesicle encloses the fluid and molecules and buds off from the cell membrane forming an endosome. The endosome moves within the cell to deliver its contents to their appropriate destinations. Substances are removed from the cytoplasm by exocytosis. In this process, vesicles budding from Golgi bodies fuse with the cell membrane expelling their contents from the cell. The cell membrane also provides structural support for a cell by serving as a stable platform for the attachment of the cytoskeleton and cell wall (in plants). Sources: â€Å"Cytoplasmic inclusions.† The Free Dictionary, Farlex, medical-dictionary.thefreedictionary.com/cytoplasmic inclusions. â€Å"Ectoplasm.† The Free Dictionary, Farlex, medical-dictionary.thefreedictionary.com/ectoplasm.â€Å"Endoplasm.† The Free Dictionary, Farlex, medical-dictionary.thefreedictionary.com/endoplasm.Goldstein, Raymond E., and Jan-Willem van de Meent. â€Å"A physical perspective on cytoplasmic streaming.† Interface Focus, The Royal Society, 6 Aug. 2015, www.ncbi.nlm.nih.gov/pmc/articles/PMC4590424/.