CIE A Level Biology复习笔记17.2.1 Natural Selection
Natural Selection Every individual within a species population has the potential to reproduce and have offspring which contribute to population growth If the offspring for every individual survived...
CIE A Level Biology复习笔记17.1.4 Variation: t-test Worked Example
Variation: t-test Worked Example Worked Example The ear length of two populations of rabbits was measured.Ear lengths of population A (mm): 62, 60, 59, 61, 60, 58, 59, 60, 57, 56, 59, 58, 60, 59, 5...
CIE A Level Biology复习笔记17.1.3 Variation: t-test Method
Variation: t-test Method A statistical test called the t-test can be used to compare the means of two sets of data and determine whether they are significantly different or not The formula for the ...
CIE A Level Biology复习笔记17.1.2 Variation: Discontinuous & Continuous
Variation: Discontinuous & Continuous The term variation refers to the differences that exist between at least two things (be it a level, amount, quantity or feature of something) In relation t...
CIE A Level Biology复习笔记17.1.1 Variation: Phenotype
Variation: Phenotype The observable characteristics of an organism are its phenotype Phenotypic variation is the difference in phenotypes between organisms of the same species In some cases, phenot...
CIE A Level Biology复习笔记16.3.3 Gene Control: Transcription Factors
Gene Control: Transcription Factors Prokaryotes use operons to control the expression of genes in cells Eukaryotes also use transcription factors to control gene expression A transcription factor i...
CIE A Level Biology复习笔记16.3.2 Gene Control: Lac Operon
Gene Control: Lac Operon Regulatory genes control structural genes and their levels of protein production Regulatory genes sometimes have control over several structural genes at once Structural ge...
CIE A Level Biology复习笔记16.3.1 Gene Control
Gene Control The nucleus of every cell in the human body contains the same genes However not every gene is expressed in every cell Not all of these genes are expressed all the time There are severa...
CIE A Level Biology复习笔记16.2.7 The Role of Gibberellin in Stem Elongation
The Role of Gibberellin in Stem Elongation In some plants species their height is partially controlled by their genes The Le gene dictates the height of some plants It has two alleles: Le and le Th...
