Unit 11: Genetics and Genetic engineering
Learning Aim B: Explore how the process of cell division in eukaryotic cells contributes to genetic
variation
Assignment Title: Cell Division
Structure and function of human chromosomes
Chromosomes are found in the nucleus and are formed
from proteins. Chromatids are identical and are copied
from chromosomes. Their function is to allow cells to
store two copies of their information. The centromere
is in the middle of the chromosome and their function
is to allow chromosomes to be equally separated from
each other. Homologous pairs contain a pair of
chromosomes, one from mother and the other from the
father. Each pair has 23 chromosomes which in total is
46. These chromosomes are not identical but are
similar in shape and size. The non-homologous pairs are known as heterologous meaning
whilst homologous pairs have same chromosomes, the heterologous has two chromosomes
that are completely different from each other. The numbered chromosomes are known as
autosomes. They are numbered in relation to their size. Humans in total have about 22 pairs
of chromosomes and the other two being the sex chromosomes. Sex chromosomes determine
the gender of the person. These are known as the x chromosome and y chromosome. Females
have 2 x chromosomes (XX), and males have 1 x and 1 y chromosome (XY).
Cell Division
The first step in the cell cycle is known as the interphase. Interphase is a period of intense
activity in order to create new cellular structures. DNA replications happens the same time as
interphase. It is when a DNA molecule produces rwo identical replicas of that DNA.
The next step of the cell cycle is known as the nuclear division stage. This stage includes the
phases prophase, metaphase, anaphase and metaphase.
The final stage of the cell cycle is the cytokinesis stage. This stage completes the cellular
division by splitting into two with each of the new cells both having nucleus.
Mitosis
Mitosis’ job is to produce cells that are identical to the parent cell genetically. Mitosis is used
for growth by produducing cells that are genetically identical to each other and repairing
damaged tissues
Learning Aim B: Explore how the process of cell division in eukaryotic cells contributes to genetic
variation
Assignment Title: Cell Division
Structure and function of human chromosomes
Chromosomes are found in the nucleus and are formed
from proteins. Chromatids are identical and are copied
from chromosomes. Their function is to allow cells to
store two copies of their information. The centromere
is in the middle of the chromosome and their function
is to allow chromosomes to be equally separated from
each other. Homologous pairs contain a pair of
chromosomes, one from mother and the other from the
father. Each pair has 23 chromosomes which in total is
46. These chromosomes are not identical but are
similar in shape and size. The non-homologous pairs are known as heterologous meaning
whilst homologous pairs have same chromosomes, the heterologous has two chromosomes
that are completely different from each other. The numbered chromosomes are known as
autosomes. They are numbered in relation to their size. Humans in total have about 22 pairs
of chromosomes and the other two being the sex chromosomes. Sex chromosomes determine
the gender of the person. These are known as the x chromosome and y chromosome. Females
have 2 x chromosomes (XX), and males have 1 x and 1 y chromosome (XY).
Cell Division
The first step in the cell cycle is known as the interphase. Interphase is a period of intense
activity in order to create new cellular structures. DNA replications happens the same time as
interphase. It is when a DNA molecule produces rwo identical replicas of that DNA.
The next step of the cell cycle is known as the nuclear division stage. This stage includes the
phases prophase, metaphase, anaphase and metaphase.
The final stage of the cell cycle is the cytokinesis stage. This stage completes the cellular
division by splitting into two with each of the new cells both having nucleus.
Mitosis
Mitosis’ job is to produce cells that are identical to the parent cell genetically. Mitosis is used
for growth by produducing cells that are genetically identical to each other and repairing
damaged tissues
