Biological Sciences Name of the Student Name of the University Author Note Task 1 Antibody System

Running head: BIOLOGICAL SCIENCES
Biological Sciences
Name of the Student
Name of the University
Author Note

BIOLOGICAL SCIENCES
1
Task 1
In the immune system of the human body, the role of antigen and antibodies are most
important and in this context, it can be stated that for providing internal security to the body,
the antibodies play the primary role. In an antibody, there are four polypeptide chains and
among them two is heavy chain and two are light chain. The immune system is activated
when antigen enters the body and then interacts with the antibody’s variable region. An
antibody is made up of a constant and a variable region. The antigen interacts with an antigen
in that variable region. The activation of the T-lymphocytes and B-lymphocytes take place
during entrance of foreign particles and so a rapid proliferation of plasma cells occurs. The
presentation of antigens to the antibodies is executed through the process of antigen
presentation that is the process of protein antigen presentation to the lymphocytes in a form
of shorter peptide fragment (Punt et al. 2019). The antigen presentation is executed by the
antigen presenting molecules such as Major histocompatibility complex class I or class II
(MHC class I or MHC class II) on the surface of antigen-presenting cells (APCs). After
identifying the antigen the defence mechanism is activated and starts the process of
proliferation. The two types of immune responses are innate immune response and acquired
immune response. The first one is first line of defence against any pathogen of the body and
this defence mechanism is gained during the time of birth. On the other hand, the second is
gained by an individual due to exposure of multiple antigens and is gained by by vaccination
(Tao and Xu 2016).
Task 2
The concept of vaccination is one of the most crucial measures for preventing various
types of diseases and it is mainly associated with providing support to the immune system of

BIOLOGICAL SCIENCES
2
the body. Vaccination mainly is used for the training process of the immune system of the
body. Primarily an individual is exposed to a specific pathogen through the process of
vaccination. During vaccination, a weak and asymptomatic version of a particular pathogen is
injected into the body and due to the exposure the immune system of the body is triggered
easily and as a result the production of memory T cells and B cells occur. As a result, body
can identify the presence of that particular pathogen in future and initiates the immunity
process (Hewitson and Maizels 2014). The inactivated vaccines are a dead or heat killed
pathogen is used to trigger the immune system and the immune system can produce specific
antibody against those pathogens. Mass vaccination refers to the vaccination campaign for a
huge number of people over a short period of time. The advantages of the mass vaccination
are associated with accelerating the disease control mechanism to enhance the coverage with
a new vaccine at the time of introducing the vaccine into the routine immunization program.
Moreover, mass vaccination can help a nation to reduce the mortality rate as a huge number
of people are covered by this disease. As a part of disadvantage it can be stated that, due to
the huge pressure of vaccinating a lot of people, the chances of immunization errors may take
place. Moreover, it can be stated that the presence of rumours can damage the vaccination
campaign (Prescott 2016).
Task 3
As per the data of the UK, it is reported that the breast cancer and lung cancer are the
most common type of cancers in the country and it is stated that like all other cancers, the
breast cancer is also characterized by the uncontrolled growth of the cells in the particular
region that is in case of breast cancer the uncontrolled cell growth is reported in the breast
(Rakha et al. 2015). According to the study of Gilbert et al. (2015), it is stated that there are a
few risk factors which are closely associated with the breast cancers among the women. The
risk factors are mainly history of breast cancer in the family members, increasing ages,

BIOLOGICAL SCIENCES
3
presence of certain genes such as BRCA1 and BRCA2, history of breast cancer in an
individual previously. Another crucial genetic factor that is associated with the onset of breast
cancer among the women is activation of HER 2 genes. According to the study of Hsu and
Hung (2016), it is stated that over expression of HER 2 genes is associated with the
transformation of cells into the malignant cells. It is reported that the expression of HER 2
genes is 10 to 40 per cent higher in breast cancer cases and so it can be stated that the role of
HER2 is crucial in the onset of breast cancer among women. Along with this, it is also
reported in the study that that for the treatment of breast cancer, the use of HER targeted
therapy has become very popular and it also indicates that the activation and overexpression
of HER2 have crucial impact on the onset of breast cancer among women. Moreover, in some
cases, it is also stated that obesity can also enhance the risks of breast cancer among the
individuals (Kuchenbaecker et al. 2017). In case breast cancer, overexpression of cyclins D1
and E take place and along with this down-regulation of cyclin dependent kinase inhibitors is
also reported. Therefore, the normal cell cycle is disrupted and uncontrolled growth is
reported. In case of lung cancer, it is stated that the alteration of the components of the G1
phase to S phase transition takes place and sequential accumulation promotes the
uncontrolled cellular proliferation of the lung cells in the human body. Therefore, the
alterations in the components of cell cycle checkpoints in the human lung tumour can cause
lung cancer in the body. Due to the uncontrolled mitosis of the lung cells, the normal lung
cells are converted into tumour cells. In case of cancer cells, the regulation of the cell cycle is
altered and as this check point regulation is not maintained properly in mitosis cell division.
As a result, the mitosis cell division becomes uncontrolled in nature (Sherr and Bartek 2017).
Task 4
A prokaryotic cell refers to the cells of the unicellular organisms which lack the
presence of cell organelles like eukaryotic cells. Moreover, this type of cell does not have any