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ENGINEERING ACTIVITY
PLAYING WITH HORMONES!
Introduction to hormones
There are two ways in which messages are sent round the body. The first is via
the nervous system, which like the phone system is ‘hard wired’ and usually operates
on a point to point basis. The second way is by means of hormones — chemical
messengers — circulating in the blood, which effectively acts as a postal.
Hormones are specialized substances that coordinate the activities of specific cells in
certain areas of the body. Hormones are produced by cells in glands, and they are
secreted by the gland into the bloodstream. The bloodstream then transports the
hormone to certain tissues, where the hormone has its effect.
The endocrine system is the system of hormone production and secretion within an
organism. The endocrine system often is compared to the nervous system, which is
composed of the brain, spinal cord, and nerves. Both nerve impulses and hormones
carry information throughout the body. Both the endocrine and nervous systems
coordinate internal activities.
Chemical nature of hormones
Chemically, most hormones belong to one of three major groups: proteins
and peptides, steroids (fat-soluble molecules whose basic structure is a skeleton of
four carbon rings), or derivatives of the amino acid tyrosine, characterized by a 6carbon, or benzene, ring.
Knowledge of the chemical nature of a hormone is important as it enables one to
predict how the hormone is produced, how rapidly it can be released in response to a
stimulus, in what form it circulates in the blood, how it acts, the time course of its
effect, and the route of administration therapeutically
Hormones and their effect
Hormone action
The chemical nature of the hormone also affects the mechanism of action. All
hormones act on cells by way of their ‘receptors’. Each hormone has its own receptor
to which it binds, matching rather like a lock and key. This is why hormones
circulating throughout the body in the blood may leave capillaries to enter the
extracellular fluid of many tissues, but act only on those cells which possess the
appropriate receptor.
Hormones in animals
Animals are different from plants because of their ability to move from one place to
another which is why they have to continuously encounter changes in their
environment. In order to maintain a steady state within the body (homeostasis), all
animals should be able to perceive these changes and adapt to them.
With increasing complexity in their structure, the number and types of cells in the
animal body increased. Thus it became necessary to have some coordinating
mechanism. Two systems have been developed for better control and coordination
of the various activities of the organisms. These systems are the nervous system and
the endocrine system
Like in humans, the endocrine system, on the other hand, is made up of glands that
secrete chemicals called the hormones. They are secreted into blood that carries
them to the sites of action.
Feeding hormones to animals
Compare to plants, animals have different kinds of hormones and other functions,
consequently the use of hormones are more harmful for the development of animals
than for plants because of all their parts and delicate organs and systems.
Animals fed with additives (which can be hormones and antibiotics) suffer from the
following setback:
Use of hormones and antibiotics leave residues in meat, milk and eggs, which is
objectionable.
Feeding with a low concentration of antibiotics may favour the proliferation of antibiotic
resistant microorganisms, which could have serious consequences for disease control in
humans and domestic animals like dogs, cats and birds.
It is argued that with the use of growth hormones, more plentiful quality meats can be
sold for affordable prices. Growth hormones are often not well looked upon due to the
use of synthetic hormones and also fears about the consumption of these hormones
from the meat products. Due to the fact that synthetic hormones are unnatural, there
are concerns about how they could affect the bodily functions of consumers. The long
term affects of the consumption of synthetic hormones have not been thoroughly
examined in animals or humans.
Genetic Engineering in animals
Genetic engineering is the science of modifying the genetic material of a cell or
living organism to produce a new trait in that organism, or to make a biological
substance such as a protein or hormone.
The genetic engineering of animals has increased significantly in recent years, and the
use of this technology brings with it ethical issues, some of which relate to animal
welfare — defined by the World Organisation for Animal Health as “the state of the
animal…how an animal is coping with the conditions in which it lives” . In addition, it
is important to try to reflect societal values within scientific practice and emerging
technology, especially publicly funded efforts that aim to provide societal benefits,
but that may be deemed ethically contentious
Several terms are used to describe genetically engineered animals: genetically
modified, genetically altered, genetically manipulated, transgenic, and
biotechnology-derived, amongst others
Hormone set up in animals and humans: They are the same
yet they differ!
Lots of human hormones are very similar to those found in certain animals. We are
at, gene level, about 90% mouse. That doesn’t mean the genes are identical but that
we have a gene that is very similar and produces a hormones (protein, enzyme or
anything else) that does the same job as a similar gene in a mouse!
The differences come about as to whether a gene is turned on (we could have a tale
if the right genes were active!), and whether the small differences in the sequence
cause big differences in the working of the hormone (or enzyme etc).
We are animals, a kind of them. If we want to focus the question from a scientific
viewpoint, all we can do is to look for some characteristics that are unique or
singularly developed in us that differentiate us fro other animals
Research methods in a survey
There are many ways to get information. The most common research methods are:
literature searches, talking with people, focus groups, personal interviews, telephone
surveys, mail surveys, email surveys, and internet surveys.
DATA COLLECTION METHODS
1 Registration
2 Questionnaires
3 Interviews
4 Direct observations
5 Reporting
HOW TO WRITE A GOOD SURVEY QUESTIONNAIRE
Words are often used in different ways by different people; your goal is to
write questions that each person will interpret in the same way. A good
question should be short and straightforward. A questionnaire should not be
too long, list of choices should not be too long, use plain English and the
question shouldn't be difficult to answer. Only through careful writing, editing,
review, and rewriting can you make a good questionnaire.