This website uses cookies to ensure you have the best experience. Learn more

Biology Practical Essay

1322 words - 6 pages




Perception of Different
Sugars by Blowflies
by Alexander Hamilton

Biology 101
October 24, 2009

Lab Partners:
Sharon Flynn,
Andi Alexander



To feed on materials that are healthy for them, flies (order Diptera) use taste
receptors on their tarsi to find sugars to ingest. We examined the ability of blowflies to
taste monosaccharide and disaccharide sugars as well as saccharin. To do this, we attached
flies to the ends of sticks and lowered their feet into solutions with different concentrations
of these sugars. We counted a positive response when ...view middle of the document...



In this experiment we tested the ability of the blowfly Sarcophaga bullata to taste
different sugars and a sugar substitute, saccharin. Because sucrose is so sweet to people, I
expected the flies to taste lower concentrations of sucrose than they would of maltose and
glucose, sugars that are less sweet to people. Because saccharin is also sweet tasting to
people, I expected the flies to respond positively and feed on it as well.

We stuck flies to popsickle sticks by pushing their wings into a sticky wax we
rubbed on the sticks. Then we made a dilution series of glucose, maltose, and sucrose in
one-half log molar steps (0.003M, 0.01M, 0.03M, 0.1M, 0.3M, and 1M) from the 1M
concentrations of the sugars we were given. We tested the flies’ sensory perception by
giving each fly the chance to feed from each sugar, starting with the lowest concentration
and working up. We rinsed the flies between tests by swishing their feet in distilled water.
We counted a positive response whenever a fly lowered its proboscis. To ensure that
positive responses were to sugars and not to water, we let them drink distilled water before
each test. See the lab handout Taste Reception in Flies (Biology Department, 2000) for

Flies responded to high concentrations (1M) of sugar by lowering their probosces
and feeding. The threshold concentration required to elicit a positive response from at
least 50% of the flies was lowest for sucrose, while the threshold concentration was highest
for glucose (Fig. 1). Hardly any flies responded to saccharin. Based on the results from all



the lab groups together, there was a major difference in the response of flies to the sugars
and to saccharin (Table 1). When all the sugars were considered together, this difference
was significant (t = 10.46, df = 8, p < .05). Also, the response of two flies to saccharin was
not statistically different from zero (t = 1.12, df = 8, n.s.).

The results supported my first hypothesis that sucrose would be the most easily
detectable sugar by the flies. Flies show a selectivity of response to sugars based on
molecular size and structure. Glucose, the smallest of the three sugars, is a
monosaccharide. The threshold value of glucose was the highest in this experiment
because a higher concentration of this small sugar was needed to elicit a positive response.
Maltose and sucrose are both disaccharides but not with the same molecular weight or
composition. It has been shown that flies respond better to alpha-glucosidase derivatives
than to beta-glucosidase derivatives (Dethier 1975). Because sucrose is an alphaglucosidase derivative, it makes sense that the threshold value for sucrose occurs at a lower
concentration than that for maltose. This might also be the reason why sucrose tastes so
sweet to people.

Other Papers Like Biology Practical

Discuss Whether Cross Cultural Research Supports the View That Gender Roles Are Innate or Learnt?

624 words - 3 pages relative contributions of biology and socialisation. If biology is the main thing in gender roles then we would expect to see that throughout cultures there would be similarities in the division of labour, whereas if socialisation is the main factor then we would expect to see variation throughout cultures. Cross cultural studies show that every society has a division of labour and behaviour by gender. It is shown that nurturing of the babies and

A Discussion on Management Theories Essay

843 words - 4 pages methodology used to describe existing theories on social sciences but also the narrow environment in which new management models could be constructed. In the year 2010 The Economist published a response to Sumatra's article, suggesting that other ways of conducting experiments in the field of management are being tested, mainly through the use of more discrete factors (such as an individual's DNA structure and hormone panels) and through more practical

human anatomy history

703 words - 3 pages HISTORY OF HUMAN ANATOMY AND PHYSIOLOGY The birth of biology: 5th - 4th century BC The Greek philosophers, voracious in their curiosity, look with interest at the range of living creatures, from the humblest plant to man himself. A Greek name is coined by a German naturalist in the early 19th century for this study of all physical aspects of natural life - biology, from bios (life) and logos (word or discourse). It is a subject with

Csec Timetable 2015

2749 words - 11 pages work, practical or written. 2 2015 Friday 08 May MORNING AGRICULTURAL SCIENCE D/A 1** AGRICULTURAL SCIENCE S/A 1** General – 1 hr 15 min MUSIC PAPER 1 Section 1 # General – 1 hr ## MUSIC PAPER 1 Sections II and III # General – 1 hr 15 min AFTERNOON HUMAN AND SOCIAL BIOLOGY 2 # General – 2 hr MUSIC 2 (General) Practical Examination to end Monday 11 May AGRICULTURAL SCIENCE D/A 2**# AGRICULTURAL SCIENCE S/A 2**# General – 2 hr


1341 words - 6 pages . During the middle ages they were translated into Latin and Arabic and became a basis for Christian theology. In 2000 years no one has came close to his brilliance except for Leonardo Da Vinci (Cunningham, Lawrence and Reich p.81). Aristotle is most famous for his detailed work about the physical world and nature, in which, a lot of his findings are used in modern day biology (“Aristotle: Philosopher”). He is most famous for his view on ethics


1278 words - 6 pages physics, chemistry, biology, and mathematics. All environmental science majors are required to complete a research project, providing a practical application of mastered course work. Environmental science majors have an option to complete the special concentration in environmental biology for environmental science majors. Earth Science Major The major in Earth science follows a similar rationale and requires the same introductory courses with a

Anatomy and Physiology

1243 words - 5 pages range in the body. They are also cellular level basic structural and functional practical units of the human body. This is shown on Figure 2 Having related structure to function of the heart and looked at structural levels all organs are important. Heart is vital, the heart supplies oxygenated blood throughout the body this aids everyday life and most organs relies on heart. REFERENCES Edwards,W.(2013)Access to HE Human Biology Anatomy Pack

Use Concepts and Ideas from the Social Approach to Explain the Key Issue You Have Studied (12 Marks)

545 words - 3 pages . ------------------------------------------------- The unit is designed to enable choice within each approach in the selection of a second key study and a key issue relevant to the approach. Within each approach there is the requirement for students to conduct a short practical investigation. ------------------------------------------------- ------------------------------------------------- Assessment: ------------------------------------------------- Examination

Using Scientific Inquiry Model In High School Biology

1484 words - 6 pages state testing on the delivery of science instruction. The Clearing House, 83, 54-57. Wilke, R.R., & Straits, W.J. (2005). Practical advice for teaching inquiry-based science process skills in the biological sciences. American Biology Teacher, 67, 534-540.

Emerging Technology

1377 words - 6 pages good to make it even better; For example the wheel, first it was made of rock, then eventually made of rubber, which is more practical to use. Necessity creates most of the useful technology; a car is a good example of this, because people wanted to travel faster and further, could you imagine traveling to a relative's house in another state by walking. Universal translation is a goal of many businesses around the globe; imagine being able to

Medicinal Chemistry

1369 words - 6 pages (e.g., lithium and platinum-based agents such as lithium carbonate and cis-platin. In particular, medicinal chemistry in its most common guise—focusing on small organic molecules—encompasses synthetic organic chemistry and aspects of natural products and computational chemistry in close combination with chemical biology, enzymology and structural biology, together aiming at the discovery and development of new therapeutic agents. Practically

Related Essays

Science Biology Practical Urine Essay

523 words - 3 pages Aim: To establish if the kidneys that produce each sample was either:1.Healthy2.diabetic3.dehydrated4.kidney deseasedPrediction:As we saw the samples given to us on the table we already saw that sample D looked obviously very different from the others, it bubbled and had froth and the colour was lighter than the oher 3. As we went over and smelled each one we found out that sample B smelled quite sweet compared to the others. We also know that

Branches Of Biology Essay

701 words - 3 pages Branches of Biology Biology, the study of life, has many aspects to it and many specializations within this broad field. Below is an alphabetical list of many of the branches of biology. Agriculture - study of producing crops from the land, with an emphasis on practical applications Anatomy - the study of the animal form, with an emphasis on human bodies Biochemistry - the study of the chemical reactions required for life to exist and

Branches Of Biology Essay

1815 words - 8 pages Branches of biology * Aerobiology – the study of airborne organic particles * Agriculture – the study of producing crops from the land, with an emphasis on practical applications * Anatomy – the study of form and function, in plants, animals, and other organisms, or specifically in humans * Arachnology – the study of arachnids * Astrobiology – the study of evolution, distribution, and future of life in the universe—also known

Report On School Science Fair

646 words - 3 pages was divided into three different subjects; physics, chemistry and biology. The objectives of the science fair are; 1. One of the programme during the activity week. 2. As a teaching platform to introduce physics, chemistry, and biology subject to lower secondary and for further understanding in the science subjects for upper secondary. 3. Demonstrate science related experiments based on practical books to students. 4. Introduction