chromosomes Flashcards
1
Q
chromosomes
A
- long thread-like structure to form part of the chromatin network of nuclei
- made of DNA wound around proteins called histones
2
Q
dicovered
A
- by chance in 1888
- absorb dye very easily (called chromosomes, coloured bodies)
3
Q
cells
A
- in somatic cells of diploid organisms
- number of chromosomes are the same
- two sets of chromosomes (diploid), from mother and from father
- for each paternal there is a maternal (homologous pair)
- DNA of each chromosome replicate to from two identical threads or chromatids joined by a centromere
- takes place in interphase
- replication is important for full complement of genetic material
4
Q
meiosis
A
- cell division that takes place in reproductive organs
- produces gametes (animals) or spores (plants)
- 2n formed to n in each daughter cell
- haploid, one set of chromosomes
- male fuses with female in fertilisation to form diploid zygote
5
Q
where does meiosis take place
A
- testis and ovaries
- spermatogenesis (formation of sperm)
- oogenesis (formation of egg)
- sporangia
- microsporangia (pollen sacs)
- megasporangia (ovules)
