(Continuing defend against herbivores. Thorns. These are modified side

(Continuing on from defence mechanisms in animals from yesterday’s notes..)

 

Animals like flounder have patterns which blend in with the background on which it is lying. (Camouflage) 

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Some animals (trout) have counter shading, which offers double camouflage.

(he showed us a picture of it and like half of the fish is one colour and the other half is different colour, probs best to google it!)

 

Butterfly fish use deflection display to fool predators. It has a huge eye spot at the rear of the body. Predators tend to attack this rather than the more vulnerable top end of the body (the head)

 

Revise Social Defence mechanisms in textbook! (we talked about it briefly but he didn’t let us really copy it down from slideshow)

 

Plant’s Structural Defence Mechanisms

 

Plants have a number of structural adaptions designed to defend against herbivores.

 

Thorns.

These are modified side branches, which can cause damage to the mouth lining of herbivores to deter attacks.

 

Spines.

In gorse (whin) leaves are reduced to short spines which are on modified branch stems.

 

In holly, the number of spines on each leaf is related to the height above ground; the higher the leaf, the fewer the spines.

 

Stings.

Nettle leaves have stinging hairs. Each is a thin capillary tube ending in a spherical tip. If an animal touches it the tip penetrates the skin, so irritating liquid can be injected.

 

The Ability To Tolerate Grazing

 

The growing points of most plant stems are found in buds well above ground level.

If these are eaten the plant may not be able to recover. (re-revise page 74&75 in textbook)

 

Low Growing Points.

Grasses have low growing points. This means that even when they are eaten, the plant can send up new leaves when the older ones get eaten.

This enables grasses to withstand high levels of grazing and makes them very successful when grazing pressure would kill other plants.

 

 

 

Regenerative Power

Some plants can grow from only very small parts, e.g. a small piece of dandelion root is capable of growing into an entire plant.

 

Rhizomes

Many grasses have rhizomes which are under storage organs and are capable of asexual reproduction and so help the plant to survive.

 

Rosette Habit

Plantain and dandelions have evolved a flat rosette habit. The leaves radiate out on very short stems and are often pressed very close to the soil to escape herbivores.

 

And then for the rest of the lesson we just did prep sheets on Meiosis 1, genetic engineering 1 and maintaing a water balance-animals 1!

Sadie, fraser and liam were all talking about some party they were going to on Saturday and discussing if they were drinking or not…..was so left out hahaha, Will miss you!! Have an amazing time, don’t study too much 😉 Good luck!! #goteamGB (ewan taught me how to do hashtag on mac and now im like addicted hahah #lol) (lol) hahha Safe flight!! xxxx

 

 

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