CIE A Level Biology复习笔记6.1.1 Nucleotides
Nucleotide Structure Nucleic acids such as DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) are macromolecules (giant molecules) Like proteins (polypeptides) and carbohydrates (polysaccharide...
CIE A Level Biology复习笔记5.2.2 Observing Mitosis
Mitosis in Root Tips: Observing & Drawing Growth in plants occurs in specific regions called meristems The root tip meristem can be used to study mitosis The root tip meristem can be found just...
CIE A Level Biology复习笔记5.2.1 The Stages of Mitosis
Mitosis: The Stages Mitosis is the process of nuclear division by which two genetically identical daughter nuclei are produced that are also genetically identical to the parent cell nucleus (they h...
CIE A Level Biology复习笔记5.1.6 How Tumours Form
How a Tumour Forms Cancers demonstrate how important it is that cell division is precisely controlled, as cancers arise due to uncontrolled mitosis Cancerous cells divide repeatedly and uncontrolla...
CIE A Level Biology复习笔记5.1.5 The Role of Stem Cells
The Significance of Stem Cells A stem cell is a cell that can divide (by mitosis) an unlimited number of times Each new cell (produced when a stem cell divides) has the potential to remain a stem c...
CIE A Level Biology复习笔记5.1.4 The Role of Telomeres
The Significance of Telomeres The ends of the chromatids in chromosomes are ‘sealed’ with protective structures called telomeres They are made of non-coding DNA (DNA that does not contain genes) th...
CIE A Level Biology复习笔记5.1.3 The Cell Cycle
The Cell Cycle Mitosis is part of a precisely controlled process known as the cell cycle The cell cycle is the regulated sequence of events that occurs between one cell division and the next The ce...
CIE A Level Biology复习笔记5.1.2 Mitosis
The Importance of Mitosis Mitosis is the process of nuclear division by which two genetically identical daughter nuclei are produced that are also genetically identical to the parent nucleus The pr...
CIE A Level Biology复习笔记5.1.1 Chromosome Structure
Chromosome Structure Chromosomes are made of one very long, condensed DNA molecule associated with proteins (in eukaryotic cells) The main proteins present are the large positively charged globular...
