Inheritance

Curriculum for Excellence links: Inheritance I recognise that we have similarities and differences but are all unique. HWB 0-47a By comparing generations of families of humans, plants and animals, I can begin to understand how characteristics are inherited. SCN 1-14a By investigating the lifecycles of plants and animals, I can recognise the different stages of their development. SCN 2-14a By exploring the characteristics offspring inherit when living things reproduce, I can distinguish between inherited and non inherited characteristics. SCN 2-14b

CfE Principles and Practice Children and young people participating in the experiences and outcomes in the sciences will: Develop as scientifically literate citizens with a lifelong interest in the sciences. Demonstrate a secure knowledge and understanding of the big ideas and concepts of the sciences. Develop a curiosity and understanding of their environment and their place in the living world. •Develop skills in the accurate use of scientific language. • Develop skills for learning, life and work.

Genetic information is passed down from one generation of organisms to another. Genetic information in a cell is held in the chemical DNA in the form of a four letter code. Genes determine the development and structure of organisms. In asexual reproduction all the genes in the offspring come from one parent. In sexual reproduction half of the genes come from each parent. Genetic information is passed down from one generation of organisms to another Genetic information in a cell is held in the chemical DNA in the form of a four letter code. Genes determine the development and structure of organisms. In asexual reproduction all the genes in the offspring come from one parent. In sexual reproduction half of the genes come from each parent.

I recognise that we have similarities and differences but are all unique. HWB 0-47a

Whose baby are you? A simple matching activity can be used to introduce the idea that offspring often resemble their parents in some way. Do the babies look exactly like their parents? each other?

Looking for similarities and differences Take a look at the animals on the laminated sheets. Together list as many similarities as you can. Next list as many differences as you can. What do we call these differences?

Variation is all around us; both between species and within the same species. Let’s look at the variation within our own species next.

Here’s looking at you! We are all members of the same species – what similarities and differences can we spot? Similarities Differences Which of these are inherited and are which down to environmental factors?

Which Characteristics are inherited?

Height standing (cm) Height sitting (cm) Outstretched arm span (cm) Left foot length (cm) Right foot length (cm) Head circumference (cm) Resting pulse rate (beats per min) Right thumb print Left thumb print Can you roll your tongue? Do you have blue eyes? Are you right handed? Do you have a hitchhiker’s thumb? Is your second toe longer than your “big” toe? Do you have dimples? Do you have unattached earlobes? Do you have a straight hairline (cf widow’s peak)? Do you have freckles? Are you male? Clasp your hands – is your right thumb on top? Do you have curly hair?

Variation within a population Discrete Continuous Tongue rolling, blood groups. Genetic control – no other influence. You either have the trait or you don’t! Height, weight, hand-span. Can be influenced by environmental factors.

Displaying your results Discrete variation Continuous variation

Where do our genes come from? From our parents Mother Father egg from mother sperm from father 2 copies of DNA in each cell 2 copies of DNA in each cell nucleus containing 1 copy of father’s DNA nucleus containing 1 copy of mother’s DNA DNA from both parents Child Cell divides Fertilised egg nucleus containing complete set of DNA (set=2 copies, 1 copy from each parent) Each cell has a complete set of DNA

Making Reebops The purpose of this practical work is: To examine how characteristics are inherited. To show how sexual reproduction is responsible for tremendous variation within a population. Investigate the factors that can influence an individual’s characteristics. By exploring the characteristics offspring inherit when living things reproduce, I can distinguish between inherited and non inherited characteristics. SCN 2-14b

Reebops My Reebop Baby The kids! Head: green play-doh Dad Mum My Reebop Baby tails Head: green play-doh Body segments: pink play-doh Humps: purple play-doh Antenna: silver pipe cleaners Noses: red or yellow pipe cleaners Legs: red or yellow pipe cleaners Eyes: wiggly eyes Tails: blue pipe cleaners Spine: wooden skewer body segment antennae legs humps head eyes noses

Reebops Mum chromosomes A a Q q E e D d M m T t L l

Reebops Dad chromosomes Q q E e D d M m T t L l

Reebops Baby No. 1 a a Q q E e D d M m T T L l

Baby Reebops: Pedigree Randomly select one gene from each parent for the 7 characteristics. Combine them on the baby Reebop recording sheet. Fill in the pedigree for your new baby by writing down each of its 7 characteristics (e.g. red nose) on the parcel tag. Choose a name for your Reebop. Collect the materials that you will need for your baby and assemble it.

Ideas for discussion: Place your Reebop in the “nursery” along with the other babies What do you notice about the features of the babies? How much genetic material does each parent provide? Where is this genetic material stored in the parent? Are there any babies that are identical? How many babies are the same as their parents?

A B Let’s work out the ratio of different lambs. In your pairs: one of you vote for lamb 1 the other vote for lamb 2. A B