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1.Movement: Itis an action by an organism or part of an organismcausing a change of position or place.
2.Respiration:The chemicalreactionsinthe cells that break downnutrientmoleculesandrelease energy formetabolismare called as respiration
3.Sensitivity:Itis theability to detect and respond to changes in theinternal or external environment.
4.Growth: Itisthe permanent increasein size and dry mass
5. Reproduction:Processesthat makes more of the same kind of organism.
6. Excretion:Itistheremoval of the waste products of metabolism and substances inexcess of requirements.
7. Nutrition: Itisthetakingin of materials for energy, growth and development.
Note:
The above are theexactwordings of definitions for the curriculum for 2023 to 2025 examinations given inthe syllabus by CAIE.
The Now there are no separate definitions for the core and the extended curriculum. Students are advised to strictly learn and write the definitions as per this material inorder to avoid losing marks in their respective exams.
Skin, kidneysand lungs are the three major organsof excretion inhumans:
1. Sweat glandsinthe skinproducesweat. This contains water, urea and salt. Excretingsweat helps keepthebody cool inhotconditions.
2. The kidneysremove excess water, saltsand urea to prevent a toxic build-up ofthesesubstancesin the body.
3. The lungs removeexcesscarbondioxide(andsome water) when breathing out
Classification of organisms
1. Organisms can be classified into groups by the features they share.
2. Classification system aims to reflect evolutionary relationships.
3. Sequence of bases in DNA are used as a means of classification.
4.Group of organisms that share a more recent ancestor (are more closely related) have base sequences in DNA that are more similar than those that share only a distant ancestor.
Key definitions:
1.Binomial system of naming species: It is an internationally agreed system in which the scientific name of an organism is made up of two parts showing the genus and the species.
2. Species: It is a group of organisms that can reproduce to produce a fertile offspring..
3.Ingestion: Itmeans to take infoodfrom the mouth.
4.Egestion: Egestionis the dischargeorexpulsionofundigested material (food) from a cell incaseofunicellularorganisms, andfrom the digestivetract via the anusincaseof multicellular organisms
BINOMIAL SYSTEM OF NAMING ORGANISMS/ RULES for SCIENTIFIC NAMES
1. The entire two-part name must be written in italics (or underlined when handwritten). •
2. The generic name (genus ) is always written first. •
3. The genus name must be capitalized. •
4. The specific epithet ( species name ) is never capitalized. Examples: Common name Scientific ( Generic ) name Modern humans Arabian camel African elephant Albatross Alpaca Asian Elephant Blackbuck Homo sapiens Camelus dromedarius Loxodonta africana Diomedeidae Lama pacos Elephas maximus Antelope cervicapra
Note: All scientific names have been derived from Latin
Some IGCSE Past Paper Questions for quick reference:
O/N/2014-P12-Q1 Ans: B
O/N/2015-P12-Q1 Ans: D
O/N/2011-P12-Q6 Ans: D
O/N/201-P12-Q7C
Links to member's Area IGCSE Biology Topic Questions and MarkSchemes :
NOTE: While learning definitions, strictly learn the definitions given as per your exam syllabus
Exam Tips
Paper 2 Exam Tips:
Some times there are direct questions on the characteristics of living organisms. You are asked directly to choose from the four options, A, B, C and D , as to which option identifies the characteristics of the living organisms.
Some questions expect you to identify the characteristics of living organisms by looking of the pictures given to you.
Then there are some tricky questions that ask you to identify one characteristic of living organisms that is made up of three small characteristics: referrecce : Q6 in this pdf
You also need to be able to identify the characteristic from its given definition
On the whole, questions based on identifying the characteristics based on the diagrams are more common