module 2 - 6.2 mitosis Flashcards
what does the nucleus contain?
chromosomes but as chromatin
what is chromatin?
a tangle of unwound chromosomes (DNA) to allow genes to be expressed (e.g. protein synthesis)
when is the DNA unwound?
during proteins synthesis
what is a chromosome?
a molecule of DNA (linear molecule)
what is a centromere made of?
protein
why are the chromosomes packaged?
so they can be moved in mitosis
what are the chromatids called when they are joined together in one chromosome?
sister chromatids
how are there 2 chromatids in the chromosome?
1 line is the original chromosome, the second is its copy of chromosome
what are centromeres drawn as when they are drawn more realistically?
2 protein complexes
how do you work out the number of chromosomes?
count the number of centromeres (when not draw as individual proteins, only as blobs)
what are the stages of mitosis?
prophase
metaphase
anaphase
telophase
what happens before prophase?
chromosomes have been replicated/ synthesised during the S phase
what are the chromosomes as a diploid number?
2n = 4
what are the chromosomes as a haploid number?
n = 2 (1 long chromosome, 1 short chromosome)
what does the n stand for in the haploid number of chromosomes?
n = number of different chromosomes based on length/ position of centromere/ bonds