AQA A Level Biology復習筆記8.2.1 Totipotent Cells
Totipotent Cells A?stem cell?is a cell that can?divide?(by mitosis) an?unlimited number of times Each new cell that is produced when a stem cell divides has the potential to?remain a stem cell?or t...
AQA A Level Biology復習筆記8.1.1 Genetic Mutations
Gene Mutations A?gene mutation?is a change in the sequence of base pairs in a DNA molecule that may result in an altered polypeptide Mutations occur?continuously?and?spontaneously Errors in the DNA...
AQA A Level Biology復習筆記7.4.1 Communities
The Definition of a Community Species?do not exist by themselves in their own isolated environment, they interact with other species forming?communities A community can be defined as: Multiple popu...
Edexcel IGCSE Maths復習筆記 1.9.1 Compound Interest
Edexcel IGCSE Maths復習筆記 1.9.1 Compound Interest What is compound interest? Compound interest is where interest is paid on the interest from the year (or whatever time frame is being used) befor...
Edexcel IGCSE Maths復習筆記 1.8.1 Reverse Percentages
What is a reverse percentage? A reverse percentage question is one where we are given?the value after a percentage increase or decrease?and asked to find the value before the change How to do rever...
AQA A Level Biology復習筆記7.3.1 Genetic Variation
Genetic Variation Phenotype variation The observable characteristics of an organism are its phenotype Phenotypic variation is the?difference in phenotypes?between organisms of the same?speci...
Edexcel IGCSE Maths復習筆記 1.7.2 Percentage Increases & Decreases
Edexcel IGCSE Maths復習筆記 1.7.2 Percentage Increases & Decreases How do I increase or decrease by a percentage? Identify “before” & “after” quantities Find percentage of “before” that we ...
AQA A Level Biology復習筆記7.2.1 Populations
Species Exist in Populations A?species?can be defined as a group of?similar organisms?that can?reproduce?to give?fertile offspring Organisms of the same species have the?same number of chromosomes?...
AQA A Level Biology復習筆記7.1.1 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 differe...
