IB DP Biology: SL复习笔记3.2.4 Non-disjunction
Non-disjunction Non-disjunction occurs when chromosomes fail to separate correctly during meiosis This can occur in either anaphase I or anaphase II, leading to gametes forming with an abnormal num...
IB DP Biology: SL复习笔记3.2.3 Genetic Variation
Genetic Variation & Meiosis Crossing over and random orientation promote genetic variation Having genetically different offspring can be advantageous for natural selection and therefore increas...
IB DP Biology: SL复习笔记3.2.2 Stages of Meiosis
DNA Replication before Meiosis Before meiosis occurs, all of the DNA inside the nucleus of the 'parent' cell is replicated This occurs during a period of the cell cycle known as interphase Once thi...
IB DP Biology: SL复习笔记3.2.1 Meiosis
Meiosis There are two processes by which the nucleus of a eukaryotic cell can divide. These are: Mitosis Meiosis Mitosis gives rise to genetically identical cells and is the type of cell division u...
IB DP Biology: SL复习笔记3.1.10 Skills: Using Databases
Use of Databases to Identify Gene Loci Use of databases to identify the locus of a human gene and its polypeptide product Following the sequencing of the whole human genome, we now know the exact l...
IB DP Biology: SL复习笔记3.1.9 Karyograms
Karyograms During the stages of mitosis, chromosomes condense (become visible) This is most notable in metaphase Staining can reveal distinctive banding patterns on chromosomes at this stage The po...
IB DP Biology: SL复习笔记3.1.8 Sex Determination
Sex Determination Sex is determined by an entire chromosome pair (as opposed to most other characteristics that are just determined by one or a number of genes) Females have the sex chromosomes (pa...
IB DP Biology: SL复习笔记3.1.7 Chromosome Number
Haploid Haploid nuclei have one chromosome of each pair Haploid cells contain one complete set of chromosomes (n) In other words, they have half the number of chromosomes compared to normal body ce...
IB DP Biology: SL复习笔记3.1.6 Eukaryotic Chromosomes
Eukaryotic Chromosomes Chromosomes in eukaryotic cells are one, very long DNA molecule associated with proteins The main proteins present are the large, positively charged globular proteins called ...
