IB Biology D2.1 Definitions
This page contains our IB Biology definitions for D2.1. By learning each one of these definitions, you will fully cover the content for IB Biology 'Cell division'.
carcinogen
Cancer-causing mutagens
chiasma
The location of crossing over that is completely random
crossing over
The exchange of DNA sequences of non-sister chromatids of homologous chromosomes
cytokinesis
Post-mitosis, a contractile ring of protein contracts to pull the plasma membrane inward, splitting the cell into two genetically identical daugther cells
diploid
A cell that contains both chromosomes in a homologous pair
haploid
A cell that contains one chromosome of the homologous pair
homologous chromosomes
Paired chromosomes with the same gene sequence but potentially different alleles
interphase
The cell's active period wherein it grows, lives, and prepares for mitosis
meiosis
The process by which one diploid nucleus divides to form four haploid nuclei
metastasis
A process where primary tumor cells detach and travel to another body site via the bloodstream
mitosis
The division of the nucleus into two genetically identical daughter nuclei
mitotic index
The ratio of the number of cells undergoing mitosis to the total number of visible cells
mutagen
A substance capable of causing a mutation
mutation
A random change to the base sequence of a gene
non-disjunction
The improper detachment of chromosomes during anaphase I or II
random orientation
The random lining up of homologous pairs at the equator during metaphase I
synapsis
The tight pairing up of homologous chromosomes
trisomy
An individual that has three homologous chromosomes instead of a pair
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