Genetic Inheritance Self Manager Reflective Learner Effective L.O: To understand how genetic inheritance occurs MUST: Recognise patterns of inheritance using one gene but appreciate that many characteristics are the result of multiple genes. SHOULD: Recognise examples of inherited traits, genotypes and phenotypes. Use a simple diagram to state how offspring have inherited traits. COULD: Use the terms allele, dominant, recessive, homozygous, and heterozygous correctly. Describe a phenotype when given the genotype. Use a Punnett square diagram to predict the outcome of a monohybrid cross. Self Manager Reflective Learner Effective Participator Team Worker

Literacy Starter 1. Unscramble the key words: NEEG LUSCUNE MAGEETS HOOOMMCRSE MAGEETS 2. Match the key word with the correct meaning: GENE Humans have 23 pairs found in the nucleus of cells Contain half the genetic information needed to make a new organism. CHROMOSOME GENE – NUCLEUS – CHROMOSOME – GAMETES; GENE-3, CHROMOSOME – 1, GAMETES - 2 GAMETES A section of DNA that codes for a characteristic 3. Make three sentences using these nine words. Choose one word from each box. DNA CELL SEXUAL REPRODUCTION SPERM GENES VARIATION EGG CHROMOSOMES GAMETES

MID – HIGH LEVEL

LOWER LEVEL

A gene (found on chromosomes) codes for a particular characteristic, e A gene (found on chromosomes) codes for a particular characteristic, e.g. eye colour. Most body cells have two copies of each gene (one from the mother, one from the father). When gametes (sex cells) are made, only one copy is passed on, so when a sperm fertilises an egg there will be two copies.

So how do we get variation? Each gene can have different versions called alleles. Dominant alleles only need one copy for the feature to be expressed. Recessive alleles need two copies for the feature to be expressed.

Representing genes There are two alleles for eye colour, B and b. B is dominant to b. B codes for brown eyes. b codes for blue eyes. Genotype: bb Phenotype: Blue eyes Homozygous: alleles are the same Genotype: BB Phenotype: Brown eyes Homozygous: alleles are the same Genotype: Bb Phenotype: Brown eyes Heterozygous: alleles are different

Team Worker Effective Participator Activity Complete the card sort activity Words you are aiming to match: ALL: gene, allele, nucleus, gametes, inherited MOST: PLUS dominant, recessive SOME: PLUS up to 4 others Team Worker This can be done as a card sort, colour code activity (jumbled up table is below the answers in the word document) Effective Participator

ANSWERS ALL – MOST - SOME Gene Short section of DNA that codes for a characteristic Homozygous  A pair of matching/ identical pair of alleles Heterozygous A pair of alleles that are different Inherited Passed on from parents Nucleus Structure in cell that contains the genetic information to make more cells Dominant allele/gene The stronger form of a gene Recessive allele/gene The weaker form of a gene Gametes The sex cells ( egg and sperm) Genotype The allele combination that a person has Phenotype The features that a person has Allele A version of a gene

Mandy and Dave Mandy has brown eyes (phenotype) She has two dominant alleles, BB (genotype) We say this is homozygous as the alleles are the same type Dave has brown eyes (phenotype) He as one dominant and one recessive gene, Bb (genotype) We say this is heterozygous as the alleles are different

Eggs Sperm B B B b B B B b B B B b Lets have a look at what colour eyes their children have Eggs Sperm B B B b B B B b B B B b

Drawing a genetic cross Mandy – BB Dave - Bb Eggs    B B  BB   b  Bb Bb  Sperm Genotypes: BB Bb Phenotypes: Brown eyes Brown eyes Chance of their child having brown eyes = 100% Chance of their child having blue eyes = 0%

Self Activities Manager LOW LEVEL: Inheritance Card Game MID LEVEL: Inheritance Card Game including student follow up HIGH LEVEL: ‘Genetic Crosses’ & ‘More Genetic Crosses’ Taking it further: Genetic crosses with co-dominance Cards need to be cut out ready for low level activity

Genetic Inheritance Self Manager Reflective Learner Effective L.O: To understand how genetic inheritance occurs MUST: Recognise patterns of inheritance using one gene but appreciate that many characteristics are the result of multiple genes. SHOULD: Recognise examples of inherited traits, genotypes and phenotypes. Use a simple diagram to state how offspring have inherited traits. COULD: Use the terms allele, dominant, recessive, homozygous, and heterozygous correctly. Describe a phenotype when given the genotype. Use a Punnett square diagram to predict the outcome of a monohybrid cross. Self Manager Reflective Learner Effective Participator Team Worker

Pupil – Teacher - Talk Reflective Learner Pupil LOW: Define the term ‘gene’ and ‘allele’, use the word ‘DNA’ in your answer MID: Describe what ‘dominant’ and ‘recessive’ mean HIGH: Eggs=Hh Sperm=Hh, draw a genetic cross Teacher comment Pupil response