BTEC Unit 11 – Learning aim B cell division
Ashleigh Clarke
Cell division within eukaryotic cells
A cell is one of the tiniest units within life as it undergoes the power of self-replication. In this
assignment I will be discussing the process of cell division such as; mitosis and meiosis alongside the
formation, function and structure of human chromosomes.
Cells divide to replace worn out cells and so organisms can nourish and take part in sexual or asexual
reproduction. In terms of nourishing and repairing the process is called mitosis whereas when
referring to reproducing so another organism can be produced is called meiosis, which involves egg
cells and sperm cells.
Human chromosomes
Located inside of the nucleus there are twenty three pairs of chromosomes. So 46 if the
chromosomes were by themselves. The chromosomes which are DNA molecules come relatively
long as they are packed with our genetic material. During the process of cell division, a double
stranded long structure like a helical structure of DNA called chromatin comes into place. The
chromatin needs to be processed and packaged up into the chromosomes complex. For cell division
to proceed, DNA has to be put into a decent structure so it can be easier to manage during the
division. This structure is beneficial as it aids DNA to be tightly wrapped around proteins if not DNA
molecules would cause chaos inside the cell as they would be tangled up and large in size. It is also
beneficial as there would be an even proportion of DNA in the initial and brand-new cell which is
needed in reproductive cells as an exact number of chromosomes is necessary for a proper function.
Human Karyotype: this shows the range of
chromosomes inside humans lined in pairs, they
are included with numbers, unusual factors and
lastly it is the complete cluster of chromosomes.
XY being the sex chromosomes.
, BTEC Unit 11 – Learning aim B cell division
Ashleigh Clarke
Picture of DNA packaging.
The term chromatids are the processed a packaged DNA that have been placed into the
chromosomes respectfully. Two of the chromatids which are a duplication are linked together
through another chromosome called centromeres. The centromeres aid the chromatids into being
able to unlink when the process of cell division takes place. The centromere is a compressed region
consisting of DNA within the chromosomes. It has a very important role of segregating chromosomes
whilst the cell cycle process is occurring within eukaryotic cells. The specialised sequence of DNA
within the chromosome links a pair of sister chromatids. These chromosomes are specialised with
telomeres, which defend the centromere ending breakage, being worn out or from the conjoining
with chromosomes it shouldn’t be fusing with. Centromeres can be described to have ‘arms’. Where
the p arms are the upper arms [short] and downward arms are q arms [long]. Every chromosome
deducing sex chromosomes are known as autosomes, as in every cell contains a generous 23 pairs
for the human body. As mentioned, this does not include sex chromosomes because they only
include twenty three individual chromosomes or 46 pairs. Sex chromosomes role are to determine
the sex of an offspring. Females have XX chromosomes and males have XY within the cells. Males are
able to generate the sex of their child before birth this is because sperm cells hold both x and y
chromosomes/gametes which are special sex cells. This occurs during fertilization. The X
chromosome are bigger than the Y chromosome. Sex chromosomes are formed through meiosis.
One function of sex chromosomes is to aid in germ cell development within mammals. Non
homologous pairs means chromosomes that aren’t a part of specific pair in meiosis there is no
pairing. Their role is to create a pathway that fixes double strand rips in the DNA structure. In terms
of chromosomes, the shape of it it varies in non-homologous pairs. Centrioles are cylinder (tube-like)
systems consisting of microtubules that are identified in eukaryotic cells. Centrioles inside the cell
aid in cell division through enabling chromosome separation. As a result, they are close to the
nucleus.
Ashleigh Clarke
Cell division within eukaryotic cells
A cell is one of the tiniest units within life as it undergoes the power of self-replication. In this
assignment I will be discussing the process of cell division such as; mitosis and meiosis alongside the
formation, function and structure of human chromosomes.
Cells divide to replace worn out cells and so organisms can nourish and take part in sexual or asexual
reproduction. In terms of nourishing and repairing the process is called mitosis whereas when
referring to reproducing so another organism can be produced is called meiosis, which involves egg
cells and sperm cells.
Human chromosomes
Located inside of the nucleus there are twenty three pairs of chromosomes. So 46 if the
chromosomes were by themselves. The chromosomes which are DNA molecules come relatively
long as they are packed with our genetic material. During the process of cell division, a double
stranded long structure like a helical structure of DNA called chromatin comes into place. The
chromatin needs to be processed and packaged up into the chromosomes complex. For cell division
to proceed, DNA has to be put into a decent structure so it can be easier to manage during the
division. This structure is beneficial as it aids DNA to be tightly wrapped around proteins if not DNA
molecules would cause chaos inside the cell as they would be tangled up and large in size. It is also
beneficial as there would be an even proportion of DNA in the initial and brand-new cell which is
needed in reproductive cells as an exact number of chromosomes is necessary for a proper function.
Human Karyotype: this shows the range of
chromosomes inside humans lined in pairs, they
are included with numbers, unusual factors and
lastly it is the complete cluster of chromosomes.
XY being the sex chromosomes.
, BTEC Unit 11 – Learning aim B cell division
Ashleigh Clarke
Picture of DNA packaging.
The term chromatids are the processed a packaged DNA that have been placed into the
chromosomes respectfully. Two of the chromatids which are a duplication are linked together
through another chromosome called centromeres. The centromeres aid the chromatids into being
able to unlink when the process of cell division takes place. The centromere is a compressed region
consisting of DNA within the chromosomes. It has a very important role of segregating chromosomes
whilst the cell cycle process is occurring within eukaryotic cells. The specialised sequence of DNA
within the chromosome links a pair of sister chromatids. These chromosomes are specialised with
telomeres, which defend the centromere ending breakage, being worn out or from the conjoining
with chromosomes it shouldn’t be fusing with. Centromeres can be described to have ‘arms’. Where
the p arms are the upper arms [short] and downward arms are q arms [long]. Every chromosome
deducing sex chromosomes are known as autosomes, as in every cell contains a generous 23 pairs
for the human body. As mentioned, this does not include sex chromosomes because they only
include twenty three individual chromosomes or 46 pairs. Sex chromosomes role are to determine
the sex of an offspring. Females have XX chromosomes and males have XY within the cells. Males are
able to generate the sex of their child before birth this is because sperm cells hold both x and y
chromosomes/gametes which are special sex cells. This occurs during fertilization. The X
chromosome are bigger than the Y chromosome. Sex chromosomes are formed through meiosis.
One function of sex chromosomes is to aid in germ cell development within mammals. Non
homologous pairs means chromosomes that aren’t a part of specific pair in meiosis there is no
pairing. Their role is to create a pathway that fixes double strand rips in the DNA structure. In terms
of chromosomes, the shape of it it varies in non-homologous pairs. Centrioles are cylinder (tube-like)
systems consisting of microtubules that are identified in eukaryotic cells. Centrioles inside the cell
aid in cell division through enabling chromosome separation. As a result, they are close to the
nucleus.
