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Unit 11 Genetic and Genetic Engineering Assignment 2
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Unit 11 Genetic and Genetic Engineering Assignment 2
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UNIT 11 GENETICS AND GENETIC ENGINEERING ASSIGNMENT 2
Explore how the process of cell division in eukaryotic cells contributes to
genetic variation:
B.P3 Explain the structure and function of human chromosomes:
Chromosomes have a filament-like structure in which the DNA is tightly
wrapped within the nucleus. Chromosomes are composed of a large,
compressed DNA molecule related to proteins in the eukaryotic cells. Every
chromosome has one molecule of DNA, that can encode for a protein or a
regulatory RNA, this is defined as the genes. The main proteins found in
human chromosomes are the large positively charged globular proteins known
as histones. Histone proteins can aid with the regulatory of gene
expression, therefore their function is to assemble and abridge the DNA
rigidly so that it fits into the nucleus, as well as that the other proteins are
mentioned to be the enzymes, which are used in the process of duplication
and restoration of the DNA. The supercoiling of DNA and proteins are known
as chromatins; therefore, chromatids and chromosomes are produced by
histones proteins, as well as that including the tightly packed DNA, which
stores the hereditary and genetic material in the nucleus of the cell. When
the cell does not have the proficiency to separate, this leads to the diffusion
of DNA and moreover, it is distributed around the chromosome; therefore,
this is referred to be the chromatins. Formation of chromatins occurs when
the DNA molecules are supercoiled around the histone proteins. During the
synthesis phase, the DNA is replicated, as well as that nuclear division
happens during mitosis. Cell division also occurs during cytokinesis, where
the cells are moving apart.
The capability to transfer hereditary information to the next generation of
offspring is what determines the structure of human beings. Chromosomes
are produced to form genetic material, which is eventually transcribed and
replicated for the formation of two genetically identical daughter cells.
This occurs during mitosis, while during meiosis, four unique daughter cells
or the heritage of an offspring are created. This is because the child inherits
genetic information from both parents DNA. A vital role that the
chromosomes adhere to is the transmission of hereditary information, as
well as that it stores the genetic instructions, which therefore makes a
child unique. Chromosomes establish that
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the offspring carries the genetic material from both parent cells, giving
them a unique characteristic from others. One chromosome is proposed by the
mother and the other from the father. Specific cells, for example the
reproductive cells require the accurate amount of the chromosomes to
divide efficiently, hence forming the new daughter cells. Therefore, the
processes of mitosis and meiosis take place, therefore forming the offspring
for the next generation. Genotype forms our phenotype, where the genotype
is classified as the full set of a gene inherited internally from the DNA of
the parent cells, whereas the observable characteristic of an organism
is known to be the phenotype. An allele is portrayed in a different format of
an identical gene, whereas the locus is the location of a specific gene
on a chromosome.
Chromosomes are a threadlike structure that transfers the genetic
information in the format of a gene. The whole chromosomes are created by
the chemical called the DNA and the histone proteins. Chromosomes are
present in the nucleus of the cell in the multicellular organism. During
interphase, which is also known as the synthesis phase, the DNA duplicates
to form two identical strands of DNA, known as the chromatids, which is
connected by a thin area known as the centromere. Besides this, the two
chromatids form the double structure of a chromosome, which are referred
to be the sister chromatids. This is because the chromatids are genetically
identical to each other, as they contain the same genes. The sister
chromatids must be genetically identical, so that the process of cell division
can occur. As the two chromatids go into the two daughter cells, during
the stages of mitosis. Each chromatid is established to have one large,
condensed DNA molecule, which is created by a sequence of genes. At the
end of the chromatids in chromosomes, the structure is sturdily secured
with the protective structures, known as the telomeres. The chromosomes
can collect and transfer genetic information from the parent cells to the
offspring, therefore the DNA, proteins and the genes play vital roles in the
human chromosomes. As these determine the characteristics of an
individual offspring, making it distinctive to that specific offspring. The DNA
molecule is copied, as well as the chromosome condenses and the
molecule twists. DNA is composed of some histone and non- histone
proteins, which creates a linear chromosome. Chromosomes contain two
identical DNA molecules, that can divide into two sections. The two sister
chromatids are joined at the centromere.
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The number of chromosomes in each organism is equal for all the cells. As well
as that, each organism contains a set number of chromosomes. Such as, a
protozoan species contains a certain number of chromosomes, about 1600
chromosomes in the cell, whereas a rice plant contains 12 pairs of
chromosomes. A human somatic (body) cell contains 46 chromosomes.
These consist of 23 pairs of homologous chromosomes. Each pair of
chromosomes contains two, one from each parent cell, therefore this means
that half of the child’s chromosomes are inherited from their mother and
the other half from their father, to obtain 23 pairs of chromosomes.
Other species have different numbers of these homologous pairs. Xy is
known as the male chromosomes. Sex cells or gametes have only one copy
of each chromosome, which are known to be haploid cells. 22 pairs of
homologous chromosomes, pairs 1-22 are called autosomes. Genes govern
many of our phenotypic and genotypic characteristics. These are the
numbered chromosomes that contain genes for anything and regulate the
inheritance of all an organism’s characteristics excluding the sex-linked ones,
that are controlled by the sex chromosomes. Inherit two XX chromosomes
to be classified as a female, therefore the 23rd pair of a chromosome is
referred to be a sex chromosome. This is the chromosome that determines
the gender of a child. Therefore, having the correct sequence chain, will
decide if the new offspring will be born as female or male. The scientific
image below portrays that there are 46 chromosomes, where two of them
are sex chromosomes, including on the gender determination.
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The genetic material of a certain cell is arranged by the chromosomes
present in the nucleus. The two categories of chromosomes are decided
sequence of chromosomes during metaphase one
by the pairing
. Meiosis is homologous and
the other one is a non-homologous 22 chromosomes are
chromosome.
homologous, which are identical to each other, therefore they contain the
same pair of chromosomes. They contain the same size and same gene at
the same positions, called the gene loci. These chromosomes synapse at
meiosis, while non-homologous chromosomes are those with different
pairings. If the alleles for characteristics are the same, the organism is said
to be homozygous for that characteristic. Therefore, the organism is
homozygote. If the alleles for characteristics are different, the organism is
said to be heterozygous for that characteristic. Therefore, the organism is
heterozygote. The allele is dominant, if it is expressed in the organism’s
phenotype, even if the organism is heterozygous. An allele is recessive, if it is
only expressed in a phenotype when the organism is homozygous. Two sets
of chromosomes are known as diploid cells, whereas one set of
chromosomes are known as haploid cells. The chromosome number
determines the number, size, and shapes of the chromosomes from a cell of
an individual or species. One major difference between homologous and
non- homologous chromosomes is that homologous chromosomes are
formed by pair of chromosomes, which contain the same gene pattern, or
two copies of each chromosome. On the other hand, non-homologous
chromosomes are formed of chromosomes that do not belong to the
same pair.
Homologous chromosomes involve alleles of identical genes in the same
loci, whereas non-homologous chromosomes contain alleles of different
genes in a different locus. They contain alleles for other genes. Non-
homologous chromosomes assemble in metaphase one, however homologous
chromosomes join during meiosis one. 22 autosomal chromosomes are called
chromosomes,
the homologous
while X and Y chromosomes are called the nonhomologous
chromosomes An overview of the chromosome structure is that the viruses,
.prokaryotes, eukaryotes and living beings contain multiple chromosome
structures and locations. Furthermore, chromosomes vary in size, with the X
chromosome, that are larger than Y chromosomes. X chromosomes contain 900
genes, whereas the Y chromosomes contain 55 genes. The chromosomes are
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