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Science Knowledge: Science 2: Life Processes and living things K2.4 Variation, Inheritance Evolution

June 06. Download K2.4_2.0a. Variation, Inheritance

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Science Knowledge: Science 2: Life Processes and living things K2.4 Variation, Inheritance Evolution

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    1. June 06 Download K2.4_2.0a Science Knowledge: Science 2: Life Processes and living things K2.4 Variation, Inheritance & Evolution This document can be freely copied and amended if used for educational purposes. It must not be used for commercial gain. The author(s) and web source must be acknowledged whether used as it stands or whether adapted in any way. Download K2.4_2.0a Authored by Liz Lakin and Keith Ross, University of Gloucestershire. accessed from http://www.ase.org.uk/scitutors/ date created March 2006

    2. June 06 Download K2.4_2.0a Variation, Inheritance & Evolution Learning Objectives To explore the science behind the headlines To establish a timeline of events leading to our current scientific understanding To identify the big ideas in this field of biology and recognise how they are interlinked To discuss modern applications & their associated issues

    3. June 06 Download K2.4_2.0a

    4. June 06 Download K2.4_2.0a

    5. June 06 Download K2.4_2.0a Variation

    6. June 06 Download K2.4_2.0a

    7. June 06 Download K2.4_2.0a The Story of the Peppered Moth

    8. June 06 Download K2.4_2.0a Human Evolution

    9. June 06 Download K2.4_2.0a Selection? What we are is determined by our genes and our environment So how do these variations become manifest within a population what does the selecting? Both environment and geneticsSo how do these variations become manifest within a population what does the selecting? Both environment and genetics

    10. June 06 Download K2.4_2.0a Father of Modern Genetics Gregor Mendel Austrian Monk (1850s) Identified the patterns of inheritance Laws of Inheritance Explain who he was and what significant role he played in our understanding of genetics. Note that like Darwin his work was not accepted until after his deathExplain who he was and what significant role he played in our understanding of genetics. Note that like Darwin his work was not accepted until after his death

    11. June 06 Download K2.4_2.0a Multiple choice questions The questions in the slides that follow are taken from a set of over 100 available from www.escalate.ac.uk/1141 Percentages quoted in the slides are for a group of 100 trainee primary teachers on entry to ITE, having obtained a C or better at GCSE, usually two or three years previously. This gives secondary trainees an insight into the misconceptions that survive a GCSE course, and all trainees some comfort that they are not alone with their own misconceptions about how genetics and evolution works.

    12. Recessive Genes If you and your partner both carry the disease for cystic fibrosis (but are not sufferers), what would be the probability that your children will then inherit the actual disease? a. 25% (1 in 4) 5% b. 33.3% (1 in 3) 19% c. 50% (1 in 2) 35% d. 100% (1 in 1 - certainty) 39% (% are for a survey of post GCSE students see notes) Cystic Fibrosis is carried by a recessive gene and follows a typical Mendelian cross:1 in 4 chance of receiving the double recessive alleles %ages are for a group of 100 trainee primary teachers on entry to ITE, having obtained a C or better at GCSE, usually two or three years previously. Cystic Fibrosis is carried by a recessive gene and follows a typical Mendelian cross:1 in 4 chance of receiving the double recessive alleles %ages are for a group of 100 trainee primary teachers on entry to ITE, having obtained a C or better at GCSE, usually two or three years previously.

    13. June 06 Download K2.4_2.0a Mendelian Cross Both parents carry the recessive gene for cystic fibrosis (c) they also carry the ordinary gene (C). The cross can be summarised as follows:

    14. June 06 Download K2.4_2.0a Eye Colour In eye colour the allele for brown eyes is dominant (B) and the allele for blue eyes is recessive (b). Try some different crosses with homozygous parents (BB or bb) and heterozygous parents (Bb):

    15. June 06 Download K2.4_2.0a So what are Genetics? Look at the person next to you and identify as many external similarities between the two of you, as you can. Now identify as many differences as possible.

    16. June 06 Download K2.4_2.0a One fertilised cell to an organism!

    17. June 06 Download K2.4_2.0a Development of an egg What will happen to the weight of a fertilised bird's egg from time of laying to just before the chick hatches? It gets lighter 6% It gets heavier 54% It stays much the same 35% (% are for a survey of post GCSE students see notes) %ages are for a group of 100 trainee primary teachers on entry to ITE, having obtained a C or better at GCSE, usually two or three years previously. %ages are for a group of 100 trainee primary teachers on entry to ITE, having obtained a C or better at GCSE, usually two or three years previously.

    18. June 06 Download K2.4_2.0a

    19. June 06 Download K2.4_2.0a Genes What are your genes? Do bacteria have genes? Is the genetic information in the sex cells the same as in other cells?

    20. June 06 Download K2.4_2.0a Lets look at cells Several types 75 billion in a human being Capable of carrying out many different functions e.g. Protection Movement Excretion

    21. June 06 Download K2.4_2.0a Importance of Proteins Click on the one statement you most agree with about why proteins are so important to living things. a. They are a nutritious food 8% b. They are the enzymes in our bodies which enable our cells to work. 37% c. When combined with oxygen, lots of energy is given off 6% d. Protein provides the structural material in all living things 45% (% are for a survey of post GCSE students see notes)

    22. June 06 Download K2.4_2.0a Material of Inheritance What are the requirements of hereditary material? Store information Permanence Ability to change (mutate)

    23. June 06 Download K2.4_2.0a Unique function of DNA Stores information for protein synthesis Makes copies of itself ~ self replication Able to change/vary/mutate

    24. June 06 Download K2.4_2.0a DNA Deoxyribonucleic Acid Molecular language ~ 4 different letters Codon three letter word most code for an amino acid GENE ~ sentence of many words (amino acids) which enables it to build PROTEINS Proteins are enzymes that enable reactions to take place in cells

    25. June 06 Download K2.4_2.0a base, nucleotide, gene, chromosome The following terms all relate to the DNA molecule. List them in relation to their size, starting with the smallest a gene b nucleotide c chromosome d bases (4% of the BEd Students got it right)

    26. DNA Click on the four sentences about human DNA that are true. a. It carries the code to make proteins. 50% b. It can pass from one generation to the next. 83% c. It can make copies of itself. 68% d. It is a single stranded molecule. 26% e. It is made of protein. 51% f. It is identical in almost every cell of our body. 66% (% are for a survey of post GCSE students see notes)

    27. June 06 Download K2.4_2.0a Protein Synthesis A simulation

    28. June 06 Download K2.4_2.0a

    29. June 06 Download K2.4_2.0a Variation from mutation Which two of the following processes leads to 'variation' in the offspring: a. Cell cloning. 4% b. Gamete formation. 34% c. Mitosis (normal cell division). 51% d. Meiosis (sex cell formation) 55% (% are for a survey of post GCSE students see notes)

    30. June 06 Download K2.4_2.0a Tracing your ancestry A mutation of which of the following could be inherited from both your parents? a. Messenger RNA 20 b. Nuclear DNA 29 c. Ribosomal RNA 13 d. Mitochondrial DNA 35 (% are for a survey of post GCSE students see notes)

    31. June 06 Download K2.4_2.0a Artificial Selection

    32. June 06 Download K2.4_2.0a Manipulation of genes Genotype Phenotype & selective breeding Manipulation of genes Biotechnology

    33. June 06 Download K2.4_2.0a How genes work Inheritance Mutations Stem cells

    34. June 06 Download K2.4_2.0a Genetic Engineering

    35. June 06 Download K2.4_2.0a What do we need to do to genetically engineer something? Location of genes Isolation of genes Removal of genes Transfer of genes Cultivation of genes

    36. June 06 Download K2.4_2.0a Where do we go from here ? Dolly ~ cloned from a mature cell by nuclear transfer Polly ~ cloned from an embryo cell, but contains a human gene which produces the human protein in the sheeps milk Why are they scientifically significant?

    37. June 06 Download K2.4_2.0a

    38. June 06 Download K2.4_2.0a What are the issues ? Monsanto monopoly 1998 Government moratorium on the growth of GM crops Media hype and scare mongering Human cloning & designer babies

    39. June 06 Download K2.4_2.0a So what do you think?

    40. June 06 Download K2.4_2.0a So what do you really think? Should scientist be allowed to alter animal genes: For medical reasons? For healthier or more efficient food production? For commercial reasons? Should scientists be allowed to alter Human genes: For medical reasons? For commercial reasons?

    41. June 06 Download K2.4_2.0a Recap What do genes do? Where do we find genes? What makes DNA so good as hereditary material? What information does DNA store? How does it store it? What happens next

    42. June 06 Download K2.4_2.0a Protein (enzyme) Synthesis Key points: Copy DNA Messenger RNA copy to site of synthesis Collect (Transfer RNA) selection of amino acids and arrange amino acids in correct sequence Builds a polypeptide chain (= protein) Several produced at one time Allows chemical reactions to take place in cell.

    43. June 06 Download K2.4_2.0a Gene Expression Switching genes on and off Stem cells and mature differentiated cells Growth = cell division and cell differentiation

    44. June 06 Download K2.4_2.0a Gene Therapy Treatment of diseases by the introduction of powders containing working copies of the defective gene ~ saturation approach Cystic Fibrosis Problems: Disease is rare in the population Expensive to treat Research pressure into common ailments

    45. June 06 Download K2.4_2.0a Genetic Engineering Transfer of genes from one species to another. How is it done? Gene Splicing Limitations ~ can only add genes

    46. June 06 Download K2.4_2.0a http://www.food.gov.uk/gmdebate/aboutgm/?view=GM%20Microsite

    47. June 06 Download K2.4_2.0a Concept map Compare building a house and cell? DNA, genes and enzymes Mitosis (cell division) and meiosis (sex) Phenotype and genotype recessive genes Growth = cell division & differentiation Mutation - natural and artificial GM debate and other issues

    48. June 06 Download K2.4_2.0a Learning log Look at the questions where were your conceptual misunderstandings?

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