Doc Brown's Biology AQA GCSE Additional Science-BIOLOGY 2 Revision Notes

Biology Unit B2.2 Tissues, organs and organ systems Study Notes

BIOLOGY UNIT 2 Biology 2 for GCSE Additional Science or GCSE Biology

REVISION NOTES GUIDE SUMMARY: What do you need to know for the examinations? What do you need to able to do in the exams? In AQA GCSE Science A examinations HT means for higher tier students only. Sorry, but I don't have much time to answer questions, but if you see any apparent errors or wish to comment, please email me. All my notes, learning objectives, comments for exam revision are based on the official AQA GCSE Science A Key Stage 4 syllabus specification.

• AQA GCSE Science BIOLOGY 2 Unit B2.2 Tissues, organs and organ systems Know that the cells of multicellular organisms may differentiate and become adapted for specific functions - specialised cells. Know that tissues are aggregations of similar cells and organs are aggregations of tissues performing specific physiological functions eg heart and liver. Know that organs are organised into organ systems, which work together to form organisms. AQA GCSE Science BIOLOGY Unit B2.2.1 Animal organs a) Know that large multicellular organisms develop systems for exchanging materials. Know that during the development of a multicellular organism, cells differentiate so that they can perform different functions. You should develop an understanding of size and scale in relation to cells, tissues, organs and organ systems. b) Know that a tissue is a group of specialised cells with similar structure and carry out a particular function. Know that examples of tissues include: muscular tissue, which can contract to bring about movement eg contraction and relaxation to move limbs glandular tissue, which can produce and secrete substances such as enzymes to enable chemical reactions and hormones to control certain functional features of an organism, epithelial tissue, which covers some parts of the body including the inside of the gut and the skin. c) Know that organs are made of different tissues acting together to perform some particular function. Know that one organ may contain several tissues. Know that the stomach is an organ that contains: muscular tissue, to churn the contents and break up the food into smaller chunks to aid digestion, glandular tissue, to produce digestive juices containing enzymes to break food down at the molecular level, epithelial tissue, to cover the outside and the inside of the stomach. d) Know that organ systems are groups of organs that perform a particular function. Know that the digestive system is one example of a system in which humans and other mammals exchange substances with the environment. Know that the digestive system includes: The glands, such as the pancreas and salivary glands produce digestive juices. In the stomach and small intestine, digestion occurs, food is churned and broken up into smaller chunks, hydrochloric acid is produced and protease enzyme (works best in acid conditions) to break down proteins, the acid also kills most of the bacteria present. The liver produces alkaline bile - which neutralises excess acid and emulsifies fats. The small intestine is where the absorption of soluble food occurs eg smaller molecules like sugars and amino acids - the products of enzyme breakdown of larger food molecules. The large intestine is where water is absorbed from the undigested food, producing faeces which are initially stored in the rectum before release through the anus! You should be able to recognise the organs of the digestive system on a diagram and know their function where described in this module (Biology B2). eg salivary glands, stomach, gall bladder, liver, large intestine, pancreas, small intestine, rectum AQA GCSE Science BIOLOGY Unit B2.2.2 Plant organs a) You should know that plant organs include stems, roots and leaves. Details of the internal structure are only needed for the leaf. Know the structure and function of palisade cells and guard cells in plants. b) You should know examples of plant tissues including: epidermal tissues, which cover the whole plant, mesophyll, between two epidermis layers, where photosynthesis happens, xylem and phloem, which transport substances around the plant eg sugars, minerals and water.

  AQA GCSE Additional Science BIOLOGY

• When revising, these pages provide you with a summary of what you need to know and be able to do.

• BUT remember, your primary source of revision are your class notes, investigations and AQA GCSE science textbooks.

• AQA GCSE Additional Science AQA GCSE Biology Unit B2 Index:

  • AQA GCSE Biology Unit B2.1 Cells and simple cell transport

  • AQA GCSE Biology Unit B2.2 Tissues, organs and organ systems

  • AQA GCSE Biology Unit B2.3 Photosynthesis

  • AQA GCSE Biology Unit B2.4 Organisms and their environment

  • AQA GCSE Biology Unit B2.5 Proteins – their functions and uses

  • AQA GCSE Biology Unit B2.6 Aerobic and anaerobic respiration

  • AQA GCSE Biology Unit B2.7 Cell division and inheritance

  • AQA GCSE Biology Unit B2.8 Speciation

• **

• Website content copyright © Dr W P Brown 2000-2013 All rights reserved on revision notes, puzzles, quizzes, worksheets, x-words, images etc. Copying of website material is not permitted

keywords:  multicellular organisms differentiated cells adapted specific functions tissues muscular glandular enzymes hormones epithelial tissue digestive system stmach small/large intestine liver bile epidermal mesophyll tissue xylem phloem

OCR GCSE 21st Century Science A - BIOLOGY  *  OCR GCSE Gateway Science A BIOLOGY

AQA GCSE Sciences - Revision Notes

PREVIOUS PAGE * NEXT PAGE * AQA GCSE SCIENCES INDEX

Website content copyright © Dr W P Brown 2000-2013 All rights reserved on revision notes, puzzles, quizzes, worksheets, x-words etc. * Copying of website material is not permitted chemhelp@tiscali.co.uk

Alphabetical Index for Science Pages Content A B C D E F G H I J K L M N O P Q R S T U V W X Y Z