Some fantastic jelly-fish answers

Do you think that the polyp form or the medusa form was the common stage in the cnidarian ancestor? Explain your answer.

-Ancestors must have come up with a plan where conditions were tough to avoid extinction- produce medusa
-Polyps come up with a very clever plan
-Scientifically it is more ethical to say the polyp stage is common to the ancestor cnidaria.

Compare and contrast the feeding behaviour of Hydra and Planaria.

-Hydra-hostile, Planaria-gracile
-Planaria are autotrophic
-Planaria embark on a journey for food.
-Planaria have a blood circulatory system.
-They have a blood transport system so that you can live on land.
-In conclusion the feeding behaviour has been compared and contrasted and a summary (in table form) has been made for convenience.
-The planarians outer layer is very choosy in allowing diffusion of gases.

Instead of having pluripotent cells, would it have been better for these phyla to have specialised cells or a blood transport system? Justify your answer (5 marks)

-Pluripotent cells might forget about producing sex cells
-The cells will able to focus in their function if they are for protection and wont have to sense as pluripotent cells would to know what’s wrong they just perform the function immediately after realising the problem,.

Perhaps worms are multidimensional beings...?

IT's the only explanation I can think of to account for worms occupying the eggs they hold inside them...!

Why are female round worms larger than males?


-I think it’s because the females contain A’s, so they can be able to produce a lot (female gametes have XX)
-Females need capacity to occupy the eggs they produce.
-Female roundworms carry the babies.

Read the question? NEVER!

Recently, I gave the following questions to some of my first year students. Bear in mind that all of the content had been covered in the lectures and so should not have evoked some of the bizarre responses that I received...Below each question are the correct answers and the mark allocation.

Answer the following questions.


a) Some species of fish have evolved a modified muscle which permits them to generate electrical charge. What are these cells called? (1 mark)
Electrocytes (1)


b) Suggest two characteristics of these modified muscles which allow these tissues to generate electrical charge. (2 marks)
They possess little to no sarcoplasmic reticulum (SR) (1), they occur in a stacked arrangement like electrical cells in series (1), they respond to action potentials (AP’s) by altering their membrane potential (1).


c) What functions do these electrical charges serve for the fish? (3 marks)
Defence (1), Navigation (1), Communication (1), Hunting (1).


This is what the students wrote. Apparently reading the question is entirely optional:

a) Because the ventricular system is not fully developed, they have a ventricular septum that separates the right and left ventricles.

a) Electroreceptors [not entirely retarded, but certainly not the kind of question you should be messing up...but things then plummeted downhill; the next two answers were from the same person]

b) They have sphincters that contract and expand. They have axons that stimulate hormone production

c) They allow water to enter into the body, surrounding all cells and achieving homeostatis

b) More fibres. Higher contraction.

c) They help them to survive in water and be able to live under extreme conditions.

c) O2 transport. Nutrient and waste transport. Hormonal transport.

c) Defence; clear murky water by electrolysis and thermoregulation. [Emphasis added]

... and you're going to WHAT?

This question was posed to a first aid instructor by a medic student...

So, I've heard that water contains lots of dissolved oxygen. Can I give it to a person who a) isn't breathing and b) has no pulse?

Answer: NOOOOO! The person is technically dead!!!!!!!

New way to classify insects

"We caught insects and classified them according to Morphogenesis..."

When in doubt, write something unbelievably dumb...

In a table on flower structure, a 2nd year university student wrote the following:

Q: Corolla [of flower]: Present/Absent

A: Yes

Courtesy of Dr Anonymous

Explain, with the aid of a fully-labeled diagram, how changes in levels of a condition typically influence the function of organisms.


“Conditions was something that has influenced the functioning of organisms since decades. Long-ago, temperatures were low as compared to now…” [yeah OK, whatever man]




Distinguish between four types of predators classified according to their functional characteristics (i.e. not by the types of prey they eat), and give an example of each.


“Herbivores - those type of predators doesn't kill the prey but it eats it piece by piece (frequently) that might be the same species or different species. e.g. goats eating grass. True predators - predators that kill the prey doesn't affect it pieces by piece but just kills it one time. e.g. lion eating zebras” [eish! mebbe I fail this ONE TIME]


“Parasitoids: Feed of host, which they then kill for only a part of their life cycle” [and then spend the other part reviving it?]



Explain the differences between resource-weighted density, organism-weighted density, and exploitation pressure, and why ecologists find it useful to distinguish between these different expressions of density.


“It is quite useful…Each individual experience different factors due to its fitness, leading to darwins theory of natural selection”

At least they eat light meals...

Q: Compare the dental formulae of humans and rats. What are the implications for the diets of both species?

A: It is evident that rats have no canines or premolars [because] rats do not tear flesh like humans do, because they do not have canines and premolars to assist them in doing so. Rats eat more lighter food as compared to humans.

Do you think they actually know what a rat is...?

Q: Compare the dental formulae of humans and rats. What are the implications for the diets of both species?

A: Only 2 carnivores per jaw on a rat and a diastema gab without teeth and 2 molars per side of a jaw. This suggests that rats have a limited diet (preferably meat) while human have a wide range of diets.

Who knew so much was at stake...

When asked to explain the activation of a protein-digesting enzyme, the student wrote the following. What they were supposed to write was something along the lines of, the enzyme is only activated in the duodenum as the pancreas doens't have any mechanisms in place to prevent self-digestion, and thus it produces the enzymes in an inactive form. This is what they actually wrote...

"…This is to ensure that it does not react with the other substance that it should not react with as prevention of self destruction."

My job is to secrete cells!

"The stomach has gastric glands which secrete chief and parietal cells."

For the record, the gastric glands are made up of chief and parietal cells. Not that it really matters, as the question was about the activation of an enzyme in the duodenum...

Digestive enzymes in the blood...?!

"Chymotrypsinogen is secreted by the pancreas and enters the duodenum via the blood stream."

Did it never occur to the student that the last thing you want is to have protein-digesting enzymes in your blood?! They would digest all your blood cells, rendering you unable to transport oxygen to your tissues and you would die.

But wait there's more...

Try these on for size:

* "Global climate change has varying theories of prediction". Really? GCC can theorise? And it's clairvoyant; being able to predict and all.

* When carbon is assimilated by plants into complex organic carbon compounds we can refer to this C as being "sunken" and the process is therefore "C sinkage". (Referring to C sinks and sources of course).

* In a question about how animal behaviour, physiology and distribution could be affected by elevated CO2 and the resultant increase in ambient temperatures, one response started: "Insect and plant physiology is affected by CO2 in the following ways..."

* A question required students to outline how biodiversity changes, as a result of global change, will affect the goods and services delivered by ecosystems to humans. This is possibly my favourite faux pas: "Ecosystems provide many cultural goods such as dyes and recreational drugs used in both religious and social ways". Talk about over-share! And pray tell, under what sorting system are dyes and drugs similar?

Directly indirect?

"The Nitrogen [N] cycle works in conjunction with the CO2 cycle as both play an important role in plant growth and soil enrichment. Thus, by causing deforestation and alike over fishing we directly influence the N cycle".

keh? Wanna make that point a little clearer?

Grammatically speaking

A few excerpts from a recent Functional Ecology exam:

* By enlarge the pattern....

* Did you know that vegetation was an abiotic measurement that should be recorded for observing changes in rainfall under global climate change? Or that rainfall is a biotic factor used to project agricultural output into the future?

* Oh yes, plants have been shown to migrate to higher altitudes to escape rising temperatures. Did you see them pick up their roots and move? Did they do it in the dead of night when there were no witnesses?

* Climate change is causing the increases in CO2 in the atmosphere as well as those increases in temperatures.

Rant: Didn't your high school teachers ever tell you to think before you ink? Good grief!

English isn't your forte is it...?

'...The receptor then makes its what to the enzyme complex it is designed. It is they activated and then releases.'

Who'd have thought?

Grasshoppers are "Wide ranging megaherbivores"

I'm not looking forward to my resistances kicking in

Question: Why does the population stabilize?

Model answer: resources become limiting at higher pop densities and births will eventually equal deaths.

Students answer: 'When the population gets too large resistance kicks in and the individuals die...'