A chickhen farmer has a flock of chickhens. She has noted how many and the size of the eggs each chickhen lays. She wants to use the information to decide who to breed to get SUPER HENS!!!!

BY JOSH STEPHENS

MARJORY

Average num. of eggs per week-5

Size- large

CHICKHENSCHICKHENS

ROSEMARY

Average num. Of eggs per week-10

Size-small

COCKERELS MUMS INFOCOCKERELS MUMS INFO

BRIAN

Average of eggs per week-6

Size-large

BOB

Average of eggs per week-8

Size-small

As you can see there is not much variation in my flock of chickhens.

Living things of the same type belong to the same species. For example, humans are one species and dogs are another species.

All the people in the class are human, even the teacher. They belong to the same species basically. Unless you have a twin in the same class everyone will look different. They have different eye colour and hair colour. 100% some will be boys and some will be girls. Some will be tall and some will be shorter.

The presence of differences between living things of the same species is called variation.

Now lets talk about different types of variation. There are two kinds of variation which are called continuous variation and discontinuous variation.CONTINUOUS VARIATIONCONTINUOUS VARIATION

Continuous variation is Continuous variation is when there is a range of when there is a range of many different values. many different values. Some examples are height, Some examples are height, weight and foot length.weight and foot length.

DISCONTINUOUS VARIATIONDISCONTINUOUS VARIATION

Discontinuous variation is Discontinuous variation is when a when a species has only species has only limited number of limited number of categories to choose from. categories to choose from. Some examples are Some examples are gender, blood group and gender, blood group and eye colour. eye colour.

Children usually look a bit like their father, and a bit like their mother, but they will not be identical to any one of their parents. This is because they get 23 chromosomes from their father and 23 chromosomes from their mother.

Each egg cell nucleus and each sperm cell nucleus contains half of the genetic information needed for an individual. Variation in a human characteristic is a result of inheritance from the parents which is called inherited variation. Some examples are gender, eye colour, hair colour, skin colour and lobed or lobeless ears.

An animal and plant species can be affected by the enviroment because of the climate, a diet maybe, accidents, culture of even just lifestyle. For example, if you eat too much you will become fat, and if you eat too little you will become skinny.

Basically environmental variation is when the enviroment changes some thing in a species.

Some features vary because of a mixture of inherited causes and enviromental causes. For example, identical twins inherit exactly the same features from their parents. But if you take a pair of twins, and twin 'A' is given more to eat than twin 'B', twin 'A' is likely to end up fatter.

Selective breeding also called artificial selection is when people take charge of selection to produce new varieties of various species.

Next i’m going to select the chickhens i’m going to breed.

I’m going to breed Rosemary from the chickhens and brian from the cockerels. First i’m going to show the egg-laying

ability.

Nn Nn

Nn Nn

Brian

Rosemary

N

N

n n100% of the offspring will lay lots of eggs per week but will still take a small number of egg laying gene though to the next generation. I will have to do more breeding to get my super hens.

NEXT I WILL SHOW THE EGG SIZE OF THE COUPLE

Ss Ss

Ss Ss

Rosemary

Brian

S S

s

s

100% of the offspring will lay large eggs but will still carry a ressesive gene of size of egg.

NOW I WILL BREED TWO OF ROSEMARY AND BRIANS OFFSPRING!

NN Nn

Nn nn

SS Ss

Ss ss

Marge

EGG-LAYING SIZE OF EGG

Fred

N

n

N n

Marge

Fred

S

s

S s

NEXT I WILL BREED TWO OF FRED AND MARGE’S OFFSPRING!

NN

NN

nn nn

SS SS

Ss Ss

Bob

Mary

N N

N

n

EGG-LAYING SIZE OF EGG

Bob

Mary

S S

S

s

NN NN

NN

NN

SS SS

SS SS

Rose

George GeorgeEGG-LAYING

N N

N

N

S

S

SS

SIZE LAYING

I have done what i wanted to do.

I took a chickhen and a cockerel and breed them together and keep breeding the offsping untill i found what i was looking for.