Chromosomes and Meiosis
Drummond, K. (2013). X doesn’t mark the spot: real shape of chromosomes revealed. [online] The Verge. Available at:
https://www.theverge.com/2013/9/25/4770712/true-shape-of-chromosomes-isnt-an-x.
Copyright © 2022 N.Raeburn 1
, Disclaimer
• The information is provided by Nikita Raeburn and is intended for studying/teaching
purposes only.
• All information displayed is sole ©Copyright of N. Raeburn, and in such may not be
downloaded, reproduced, copied, defaced, edited or used in any way without
written permission.
• All information is based on the IEB (Independent Examinations Board) syllabus.
• Various textbooks, articles and websites were used in compiling the information.
• The information in these notes cover a majority of topics, however it is advised to
keep your own personal textbook/study guide near as the notes may not contain
everything suited to certain examiners preference.
Copyright © 2022 N.Raeburn 2
, Chromosomes
• Every somatic cell contains the same number of diploid
chromosomes (2n = 46)
• Chromosomes appear in pairs with one coming from the
mother (maternal) and the other from the father (paternal)
• These pairs are known as homologous chromosomes – this
ensures that the organism has characteristics from both the
maternal and paternal sides
Chromosome
Short arm DNA
Gametes
• Have only one set of chromosomes known
as the haploid chromosome (n=23) Centromere
• When the egg and sperm fuse during
fertilisation they form the zygote (2n)
Long arm
3
Copyright © 2022 N.Raeburn
, Homologous Chromosomes
Gene (n.d.). Meiosis. - ppt download. [online] slideplayer.com. Available at: https://slideplayer.com/slide/15025968/ [Accessed 27 Jan. 2022].
Copyright © 2022 N.Raeburn 4
Drummond, K. (2013). X doesn’t mark the spot: real shape of chromosomes revealed. [online] The Verge. Available at:
https://www.theverge.com/2013/9/25/4770712/true-shape-of-chromosomes-isnt-an-x.
Copyright © 2022 N.Raeburn 1
, Disclaimer
• The information is provided by Nikita Raeburn and is intended for studying/teaching
purposes only.
• All information displayed is sole ©Copyright of N. Raeburn, and in such may not be
downloaded, reproduced, copied, defaced, edited or used in any way without
written permission.
• All information is based on the IEB (Independent Examinations Board) syllabus.
• Various textbooks, articles and websites were used in compiling the information.
• The information in these notes cover a majority of topics, however it is advised to
keep your own personal textbook/study guide near as the notes may not contain
everything suited to certain examiners preference.
Copyright © 2022 N.Raeburn 2
, Chromosomes
• Every somatic cell contains the same number of diploid
chromosomes (2n = 46)
• Chromosomes appear in pairs with one coming from the
mother (maternal) and the other from the father (paternal)
• These pairs are known as homologous chromosomes – this
ensures that the organism has characteristics from both the
maternal and paternal sides
Chromosome
Short arm DNA
Gametes
• Have only one set of chromosomes known
as the haploid chromosome (n=23) Centromere
• When the egg and sperm fuse during
fertilisation they form the zygote (2n)
Long arm
3
Copyright © 2022 N.Raeburn
, Homologous Chromosomes
Gene (n.d.). Meiosis. - ppt download. [online] slideplayer.com. Available at: https://slideplayer.com/slide/15025968/ [Accessed 27 Jan. 2022].
Copyright © 2022 N.Raeburn 4
