Showing posts from September 18, 2016

Brief notes about cell

CELL ORGANELLES - NOTES CELL THEORY Cells are the basic unit of life.  The Cell Theory states that: 1) All organisms are made up of one or more cells and the products of  those cells. 2) All cells carry out life activities ( require energy, grow, have a limited size). 3) New cells arise only from other living cells by the process of cell division.
THE THREE MAIN COMPONENTS OF ANY PLANT OR ANIMAL CELL ARE: 1. PLASMA MEMBRANE/ CELL MEMBRANE Structure- a bilipid membraneous layer composed of proteins and carbohydrates.  It is fluid like. Function - the cell membrane separates the cell from its external environment, and is selectively permeable (controls what gets in and out).  It protects the cell and provides stability. Proteins are found embedded within the plasma membrane, with some extending all the way through in order to transport materials. Carbohydrates are attached to proteins and lipids on the outer lipid layer.
2. CYTOPLASM Structure - The jelly-like substance composed of mainly water and f…

Basics about circuits

Circuit Symbols and Circuit Diagrams Thus far, this unit of The Physics Classroom tutorial has focused on the key ingredients of an electric circuit and upon the concepts of electric potential difference, current and resistance. Conceptual meaning of terms have been introduced and applied to simple circuits. Mathematical relationships between electrical quantities have been discussed and their use in solving problems has been modeled. Lesson 4 will focus on the means by which two or more electrical devices can be connected to form an electric circuit. Our discussion will progress from simple circuits to mildly complex circuits. Former principles of electric potential difference, current and resistance will be applied to these complex circuits and the same mathematical formulas will be used to analyze them. Electric circuits, whether simple or complex, can be described in a variety of ways. An electric circuit is commonly described with mere words. Saying something like "A light b…

MAT - verbal and nonverbal reasoning

Learn Probability - Simple and Easy.

Complete information from "maths is fun"Visit this - ProbabilityHow likely something is to happen. Many events can't be predicted with total certainty. The best we can say is how likely they are to happen, using the idea of probability. Tossing a Coin  When a coin is tossed, there are two possible outcomes: heads (H) ortails (T) We say that the probability of the coin landing H is ½. And the probability of the coin landing T is ½. Throwing Dice  When a single die is thrown, there are six possible outcomes: 1, 2, 3, 4, 5, 6. The probability of any one of them is 1/6. Probability  In general: Probability of an event happening = Number of ways it can happenTotal number of outcomes
Example: the chances of rolling a "4" with a dieNumber of ways it can happen: 1 (there is only 1 face with a "4" on it) Total number of outcomes: 6 (there are 6 faces altogether) So the probability = 16 Example: there are 5 marbles …

Heredity - Biology.

Heredity is the genetic information passing for traits from parents to their offspring, either through asexual reproduction or sexual reproduction. This is the process by which an offspring cell or organism acquires or becomes predisposed to the characteristics of its parent cell or organism. Through heredity, variations exhibited by individuals can accumulate and cause some species to evolvethrough the natural selection of specific phenotype traits. The study of heredity in biology is called genetics, which includes the field ofepigenetics.

Relation to theory of evolution[edit] Main article: Charles Darwin See also: Evolution When Charles Darwin proposed his theory of evolution in 1859, one of its major problems was the lack of an underlying mechanism for heredity.[20] Darwin believed in a mix of blending inheritance and the inheritance of acquired traits (pangenesis). Blending inheritance would lead to uniformity across populations in only a few generations and then would remove vari…