1. Who are we?
Write a brief 2-3 sentences to describe why these people are important!
Friedrich Miescher
James Watson
Francis Crick
Rosalind Franklin
Maurice Wilkins
Oswald Avery
Erwin Chargaf

2. What is Genetics????

3. DNA, Chromosomes and Genes

4. DNA Cells carry instructions in the nucleus
These instructions are about the whole organism ( all your features)
These instructions are carried on a chemical called DNA
Deoxyribonucleic acid
DNA is a double helix
RNA is the messenger that takes the information outside the nucleus to be translated into proteins

5. DNA and RNA

6. DNA structure showing nucleotides phosphate backbone and H bonds

9. Chromosomes Chromosomes are lengths of DNA Humans have 46 chromosomes
These are in homologous pairs ( 23 pairs)
Homologous chromosomes have the instructions about the same features
We have 2 sets of chromosomes so our cells are called diploid ( 2n)
1 set from Mum and 1 set from Dad
All your genetic material is your genome

10. Our Chromosomes We have 22 pairs of autosomes
We have 1 pair of sex chromosomes
Male = XY
Female = XX

11. DNA and chromosomes
chromatid
proteins
DNA

12. Comparisons in size

13. Instructions
1. Add 25g NaCl to 80mL
dishwashing liquid to make up the volume to 1L
2. Stir to dissolve the NaCl but try to avoid frothing
3. Add 100mL of the NaCl solution to a cut and mashed
kiwifruit in a 250mL beaker
4. Incubate in a water bath for 15 mins
5. Filter the kiwifruit mixture until you get 4cm in a test tube
6. Run ice cold Meths slowly down the side of the test tube so
that is forms a 1cm layer on top of the kiwifruit filtrate
7. At the interface of the 2 layers white DNA strands will form
8. Use a pipette or hook to extract these
9. Put onto a microscope slide
10. Stain with Bromothymol blue

15. Karyotype – chromosome map
A Karyogram is a photo of chromosomes
A replicated chromosome

16. Human Karyotype

18. Diagram of 1 set of chromosomes showing the sex chromosomes

19. Genes
Genes are lengths of a chromosomes that have instructions for one feature
Genes control your features
A chromosomes is made up of many genes
We have about 31,000 genes
For any one feature there are different versions eg. brown, black, blonde for hair colour
The different versions of a gene are called alleles

20. Genes - proteins

21. Genes to Proteins A triplet of bases codes for 1 amino acid
A protein is made up of a long chain of amino acids

22. Your genes You have alleles for each feature ( one from each parent)
If alleles are different usually only one shows up
This is called the dominant allele
The other allele is called recessive
Your genes are called your Genotype
Your features are called your Phenotype

23. Inheritance: How genes are passed on to offspring – genetic crosses
When doing crosses we give genes alphabet letters
eg. Brown eyes - dominant B
Blue eyes - recessive b
Each sex cell ( sperm and egg ) have only 1 allele for each feature
eg. B or b
The offspring have 2 alleles

24. More genetics terms Homozygous – 2 alleles the same eg. BB or bb
Heterozygous – 2 different alleles
eg. Bb

25. Mendel Gregor Johann Mendel is called the “father of genetics”
He was an Austrian monk who did lots of experiments on peas for 12 years
He studied how features were inherited
He drew up crosses to predict the offspring of known parents
He predicted ratios of inherited features and proposed the “laws of genetics”

26. wrinkled
round
Punnett square

27. Pedigree analysis Used for looking at family histories
Used for working out
Genotypes
Whether traits are dominant or recessive, autosomal or sex-linked
Genetic counselling

28. Pedigrees

29. Pedigree symbols

30. Sex-linked genes
Some genes for features are found on one sex chromosome and not the other
Most of these features are found on the X chromosome
These are called sex-linked
eg. Red-green colour blindness, haemophilia

31. Sex linked inheritance
Haemophilia
Bleeders disease where the blood does not clot properly

33. Types of genetics problems
Punnet squares – predicting ratios of offspring
Pedigrees – to work out genotypes
Test crosses – to work out if a parent is homozygous or heterozygous for a particular feature ( trait)

34. Rules for doing genetic crosses
Assign letter to the alleles
Write the phenotype
Write the genotype
Write the gametes
Draw up a Punnett square
Work out the ratios
Answer the question

35. NCEA information 1.9
5 Biological ideas relating to genetic variation are limited to concepts and processes connected with:
• the continuity of life based on the inheritable nature of DNA
• links between DNA and variation in phenotypes
• variation in phenotypes as adaptive features.
6 Biological concepts and processes relating to the inheritable nature of DNA will be selected from:
• the roles of DNA in both carrying instructions to the next generation and determining phenotype
• the relationship between DNA, alleles, genes, and chromosomes
• the way in which genotype determines phenotype
• the way chromosomes exist as pairs so that individuals inherit two copies of each gene.

36. NCEA information 1.9 continued
7 Biological concepts and processes relating to variation in phenotype will be selected from:
• the significance of an allele as an alternative version of a gene
• the role of mutations in forming new alleles
• the role of meiosis in generating gametes (students are not required to provide the names of the stages of meiosis)
• the significance of sexual reproduction (in producing a new mix of alleles)
• the patterns of inheritance involving simple monohybrid inheritance showing complete dominance, sex determination, possible genotypes, and phenotype ratios.
8 Biological concepts and processes relating to variation in phenotypes as adaptive features will be selected from:
• inheritable and non-inheritable variations that exist within a group of living organisms
• differing rates of survival by various members of a group may depend on their phenotype
• the importance of variation within populations (population and species survival) in a changing environment such as pest infestation, disease, drought, or flood
• the advantages and disadvantages of sexual reproduction.
9 The student must be familiar with the following genetic language and conventions: gene, allele, mutation, genotype, phenotype, gamete, zygote, dominant, recessive, homozygous, heterozygous, pure breeding, Punnett square, and pedigree chart.

37. NCEA questions