D. Crowley, 2008

To understand that some features can be inherited

Tuesday, April 18, 2023

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 VariationEnvironmental Variation

What causes the differences below?

Environmental VariationEnvironmental Variation

Amount of water; light; nutrients; space etc…

What causes the differences below?

Environmental VariationEnvironmental 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 VariationEnvironmental 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 & EnvironmentalInherited & Environmental

Copy out these variations in your book, and say if they are inherited or environmental variations: -

Hair colour (natural)Hair lengthLanguageEye colourGender (male / female)WeightColour of flowers (hydrangeas)Skin colourReligionLobbed / lobeless earsTattoos

Inherited Or EnvironmentalInherited Or Environmental

InheritedEnvironmentalEnvironmentalInheritedInheritedEnvironmentalEnvironmental (acid / alkali soil)InheritedEnvironmentalInheritedEnvironmental