Biology - its not just about exams

The purpose of this page is to introduce you to some Biology that is interesting for its own sake, rather than because its "on the syllabus." Scroll down and read the updates to see if any catch your interest.

The largest squid on record was caught today. It is 10m long and weighs nearly half a tonne. It is one of the very rare Colossal Squid species, which is larger and more agressive than the Giant Squid species. This species of squid has the largest eye of any known species on the planet. In fact, this specimen has eyes larger than dinner plates.

	The Biology of Sleep
A sleeping student... never at Wellington		Animals sleep too

We spend about 8 hours a day, 56hs a week, 224hrs a month and 2,688hrs a year sleeping. In fact, one third of our lives is spent asleep. Why?

Although our eyes are closed and our muscles are relaxed, our brains are very active during sleep. In fact, the relative electrical activity of the brain is what characterises the different stages of sleep. There are four stages;

Alpha: this marks the transition from wakefulness to sleep

Beta: light sleep, the first true stage of sleep

Theta: moderately deep sleep. The brain shows clear slow waves of electrical activity, different from either of the previous stages

Delta: even deeper phase of slow wave sleep. During this phase the eyes make rapid movements (REM). This is the restorative phase of sleep and is affected by drugs, caffeine, noise etc.

There are many theories as to the purpose of sleep. However, most agree that sleep serves a restorative function, i.e. it helps us recover from activity during the day. Research has shown that cells divide, tissue is synthesized and growth hormones are released during delta sleep, implying that the body grows and recovers during this phase of sleep. This theory is supported by the observation that children, young people and athletes spend a larger portion of their sleep in slow wave sleep than other people.

However, other studies have shown that sleep is important for learning as well. The programming - reprogramming theory of sleep argues that unimportant information is "erased" from the brain during slow wave sleep and "important" information is encoded in memory. This is supported by the observation that babies and adults undergoing intense intellectual training spend more time in delta & theta sleep than control subjects.