D. Crowley, 2008

 To understand that some features can be inherited Wednesday, May 20, 2015

 Complete the animals crossword

 Look at the following pictures – all the individuals are from the same species  Non of the individuals are identical (they all have slight variations), however they have all inherited similar characteristics (e.g. a trunk; a tail fin; whiskers etc…)

 Offspring usually look a little like their father, and a little like their mother, but they will not be identical to either of their parents  Why is this?  Offspring get half of their inherited features from each parent  During fertilisation, the nucleus from the sperm cell joins with the nucleus in the egg cell, and a new nucleus is formed with all the genetic information needed

 Some variations are inherited, whilst other variations are due to environmental factors  Inherited variation is a characteristic you have got from your parents - what can you inherit? ◦ Gender ◦ Eye colour ◦ Hair colour ◦ Skin colour ◦ Lobed or lobeless ears Lobed (left) & lobeless (right) ears

 Look at the pictures below - can you see any similarities or differences? Gwyneth Paltrow & Blythe Danner; Kirk & Michael Douglas; Elizabeth & Jerry Jagger; Martin & Charlie Sheen; Sharon & Kelly Osbourne

 Offspring are similar, but not identical to their parents  Some characteristics are inherited - and this occurs in both animals and plants  Why though do we not look 100% like our parents?  Why do we not look 100% like our siblings (if we are both from the same biological parents)?

 During fertilisation ½ the genes are transferred from the male (sperm), and ½ from the female (egg)  This is why you inherit characteristics from both your mum and your dad (½ from each)  Likewise, your siblings (brothers and sisters) also have ½ the genes of your mum, and ½ of your dad (but your are not identical to them because the genes can mix slightly)  Thousands of genes make up a living organism, and these can sometimes come in different forms - e.g. a gene for blue eyes, and a gene for brown eyes  This is why your parents may both have one eye colour, but you might have another

 Complete the inherited worksheet

 Look at the pictures of Posh – what differences can you see?  What causes these differences? Environmental Variation

 What causes the differences below? Environmental Variation  Amount of water; light; nutrients; space etc…

 What causes the differences below? Environmental Variation  The amount of food we eat can drastically change the way we appear  This is an example of environmental variation!

 Characteristics of animals and plants can be affected by factors such as climate, diet, accidents, culture and lifestyle  If you eat too much you will become heavier, and if you eat too little you will become lighter  A plant in the shade of a big tree will not be able to photosynthesise as quickly as one in the sunshine, so it will be smaller Environmental Variation  Variation in a feature as a result of the surroundings, is called environmental variation

 Some variation within a species is inherited, and some variation is due to the environment  Variation in a feature as a result of inheritance from the parents, is called inherited variation  Variation in a feature as a result of a certain factor in the surroundings is called environmental variation Inherited & Environmental

 Copy out these variations in your book, and say if they are inherited or environmental variations: - Hair colour (natural) Hair length Language Eye colour Gender (male / female) Weight Colour of flowers (hydrangeas) Skin colour Religion Lobbed / lobeless ears Tattoos Inherited Or Environmental Inherited Environmental Inherited Environmental Environmental (acid / alkali soil) Inherited Environmental Inherited Environmental