Topic 18 – Variation and Selection Lockdown revision never really happened? See our Section 5: Reproduction and Inheritance 5.6 Variation, Change and Evolution Genetic variation in a population Change by genetic mutation Evolution by natural selection 2. a The X and Y sex chromosomes are inherited independently of hair colour and texture.

Your message goes here SAT II Biology Session 31 Human influences on the environment 2-2 Natural selection explains how evolution occurs. Fitness is defined as the probability of an organism surviving and reproducing in the environment in which it is found. This PowerPoint explains the difference between continuous and discontinuous variation. If you continue browsing the site, you agree to the use of cookies on this website. Variation is defined as differences between individuals of the same species; Phenotypic variation is the difference in features between individuals of the same species; Some of these differences are caused by differences in genes, which is genetic variation; Phenotypic variation can be divided into two types depending on how you are able to group the measurements: Igcse edexcel 5.6 variation, change and evolution Upon the use of antibiotics, most bacteria of a certain strain will die. b Mainly acquired; manual skills, language.

Updated to follow Mary and Geoff Jones Cambridge IGCSE Biology Coursebook 3rd edition. Page 202 1. a Mainly inherited; facial features, ability to talk. Notes for the CIE IGCSE Biology topic: 18. A histogram should show normal distribution, with most individuals around the average value and a few at the extremes. This is known as evolution. 2 (i ) Entirely genetic: eye colour, maleness, blood group, natural hair colour, sickle-cell anaemia. Adaptive features are inherited functional features of an organism that increases in fitness. Organisms of the same species vary in many ways. So whereas the father has brown eyes and straight hair, his sons could have blue eyes and straight We've partnered with The Profs to give you access to the very best tutoring experience.A member of The Profs team will be in touch to discuss your tuition plan once you've submitted your details.Please answer the following questions so that a customer service representative can start your search for perfect tutor.We've partnered with The Profs to give you access to the very best tutoring experience.A member of The Profs team will be in touch to discuss your tuition plan once you've submitted your details.Please answer the following questions so that a customer service representative can start your search for perfect tutor. Artificial selection is the intentional reproduction of animals and plants by By using this method, the organisms can pass down favourable traits to their offspring to produce more organisms with the characteristics that we want. Variation can be caused by various factors.

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2. a The X and Y sex chromosomes are inherited independently of hair colour and texture.

See our 23 Variation and selection -answers 1 The two main causes of heritable variation are mutations and recombinations. This produces many more bacteria that also have the resistant gene. Eventually, the antibiotic will be ineffective due to the abundance of resistant bacteria. The most important ones that you need to be aware of is: Sexual reproduction The mixing of genes from the father & mother to produce offspring with a completely unique genetic make-up causes variation; Mutation The ability to roll your tongue, blood group (A, B, AB, O) and hand dominance (left or right handed) are all examples.Discontinuous variation is represented as a bar chart. Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Now customize the name of a clipboard to store your clips. Our online Biology GCSE catchup courses on 24-25 August will review Year 10 …

c More or less equal mixture: body build, athleticism. We adhere to the GDPR and EU laws and we will not share your personal information with or sell it to third-party marketers. Continuous variation is influenced by both genes and the environment, resulting in a range of phenotypes between two extremes, e.g. Define variation as differences between individuals of the same species; Distinguish between phenotypic variation and genetic variation; State that continuous variation results in a range of phenotypes between two extremes, e.g. IGCSE Edexcel Biology height in humans CIE IGCSE Biology exam revision with questions and model answers for Variation & Selection Multiple Choice 1.

Variation, selection and evolution. If you continue to use this site we will assume that you are happy with it. IGCSE Edexcel Xavier DANIEL, Ph.D. Variation, selection and evolution.