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...
CIE A Level Biology复习笔记16.2.6 Genes, Proteins & Phenotype
Genes, Proteins & Phenotype A gene can affect a phenotype of an organism A gene codes for a single protein The protein affects the phenotype through a particular mechanism The phenotype of an i...
CIE A Level Biology复习笔记16.2.5 Predicting Inheritance: Chi-squared Test
Predicting Inheritance: Chi-squared Test The difference between expected and observed results in experiments can be statistically significant or insignificant (happened by chance) If the difference...
CIE A Level Biology复习笔记16.2.4 Predicting Inheritance: Test Crosses
Predicting Inheritance: Test Crosses A test cross can be used to deduce the genotype of an unknown individual that is expressing a dominant phenotype The individual in question is crossed with an i...
CIE A Level Biology复习笔记16.2.3 Predicting Inheritance: Dihybrid Crosses
Predicting Inheritance: Dihybrid Crosses Monohybrid crosses look at how the alleles of one gene transfer across generations Dihybrid crosses look at how the alleles of two genes transfer across gen...
CIE A Level Biology复习笔记16.2.2 Predicting Inheritance: Monohybrid Crosses
Predicting Inheritance: Monohybrid Crosses Monohybrid inheritance looks at how the alleles for a single gene are passed on from one generation to the next Known information about the genotypes, phe...
CIE A Level Biology复习笔记16.2.1 Key Terms in Genetics
Key Terms in Genetics Genes & alleles The DNA contained within chromosomes is essential for cell survival Every chromosome consists of a long DNA molecule which codes for several different prot...
CIE A Level Biology复习笔记16.1.5 Meiosis: Sources of Genetic Variation
Meiosis: Sources of Genetic Variation Having genetically different offspring can be advantageous for natural selection Meiosis has several mechanisms that increase the genetic diversity of gametes ...
CIE A Level Biology复习笔记16.1.4 Identifying the Stages of Meiosis
Identifying the Stages of Meiosis Cells undergoing meiosis can be observed and photographed using specialised microscopes The different stages of meiosis have distinctive characteristics meaning th...
CIE A Level Biology复习笔记16.1.3 Meiosis in Animal & Plant Cells
Meiosis in Animal & Plant Cells Meiosis is a form of nuclear division that results in the production of haploid cells from diploid cells It produces gametes in plants and animals that are used ...
CIE A Level Biology复习笔记16.1.2 Homologous Chromosomes
Homologous Chromosomes In diploid cells there are two complete sets of chromosomes in the nucleus Chromosomes have a characteristic shape They have a fixed length The position of the centromere is ...
