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Revision HBS3B. Structure of the paper Section One - Multiple-choice – 20 questions – 40 marks Answer all the questions on the separate Multiple-choice.

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Presentation on theme: "Revision HBS3B. Structure of the paper Section One - Multiple-choice – 20 questions – 40 marks Answer all the questions on the separate Multiple-choice."— Presentation transcript:

1 Revision HBS3B

2 Structure of the paper Section One - Multiple-choice – 20 questions – 40 marks Answer all the questions on the separate Multiple-choice Answer Sheet provided. For each question shade the box to indicate your answer. Use only a blue or black pen to shade the boxes. If you make a mistake, place a cross through that square, do not erase or use correction fluid, and shade your new answer. Marks will not be deducted for incorrect answers. No marks will be given if more than one answer is completed for any question. Suggested working time 30 minutes Section Two - Short answer - 10 questions – 100 marks Write answers in this Question/Answer Booklet. Suggested working time 90 minutes Section Three - Extended answer – select 2 questions from 3 – 60 marks (30 each) Write answers in this Question/Answer Booklet. You must be careful to confine your responses to the specific questions asked and to follow any instructions that are specific to a particular question. Total marks 200 Your mock exam is only on second semester’s work – 3B. The WACE will be on the whole course (A and B)

3 Hominins Describe 3 similarities that can be seen in these 3 skeletons. Explain the advantage of each of these features Describe 2 differences in the skeleton that can be seen between Australopithecus and Homo sapiens Describe 2 differences in the skeleton that can be seen between Homo erectus and Homo sapiens Describe the differences in artefacts that you would expect to find associated with each skeleton.

4 Hominins Describe 3 similarities that can be seen in these 3 skeletons. S-shaped spine, wider pelvis, carrying angel on femur, foramen magnum more cntrally located at base of skull, lose of opposability in 1 st digit of feet, 2 arches, parallel toes Explain the advantage of each of these features All of these allow bipedalism Describe 2 differences in the skeleton that can be seen between Australopithecus and Homo sapiens Homo sapiens has larger, more rounded skull, smaller jaws and teeth, legs are longer than arms Describe 2 differences in the skeleton that can be seen between Homo erectus and Homo sapiens Homo sapiens has larger, more rounded skull, smaller jaws and teeth and a chin Describe the differences in artefacts that you would expect to find associated with each skeleton. Australopithecus – stone pebble tools Homo erectus – stone core tools, fire, huts Homo sapiens – blade tools, tools made of ivory or bone as well as stone, fire, huts, burials, artwork, (pottery, weaving, metals, writing, towns – modern man)

5 Protein synthesis Name structures: Indicate on the diagram the location of transcription translation the template strand DNA a codon an anticodon a protein

6 Protein synthesis Name structures: 1 mRNA 2 tRNA 4 Ribosome Indicate on the diagram the location of transcription translation the template strand DNA a codon an anticodon a protein transcription translation DNA codon anticodon protein

7 Ageing For each of the systems shown: a)name one problem or disease that can occur as a person ages b)describe one treatment or technology that can be used to overcome or prevent this problem Name one other problem or disease associated with ageing, and describe its treatment.

8 Ageing For each of the systems shown: a)name one problem or disease that can occur as a person ages b)describe one treatment or technology that can be used to overcome or prevent this problem Name one other problem or disease associated with ageing, and describe its treatment. Diabetes – insulin, loss of hair – transplant/wig, loss of teeth - dentures Arthritis, osteoporosis Pain killers, walkers, hip replacements Heart attack, valve failure, varicose veins Heart, blood vessel & valve transplants, medication Alzheimer's, Parkinson’s, loss of vision or hearing Drug treatments, glasses, hearing aids

9 Using DNA technology The diagram opposite shows the results of gel electrophoresis on members of a family. One of the children is adopted. a)Which child is it? b)How can you tell? One of the children is the result of a previous marriage of one of the parents. a)Which child is it? b)Who is the genetic parent & who is the step-parent? c)How can you tell?

10 Using DNA technology The diagram opposite shows the results of gel electrophoresis on members of a family. One of the children is adopted. a)Which child is it? S2 b)How can you tell? No genes in common One of the children is the result of a previous marriage of one of the parents. a)Which child is it? D2 b)Who is the genetic parent & who is the step-parent? Mother is gene dor, father is stepfather c)How can you tell? Daughter shares genes with mother but not father

11 Cellular control of gene expression Describe the roles of: regulator genes operator genes promoter genes Why are they necessary?

12 Gene expression Gene expression is controlled by a number of factors. Regulator genes produce proteins that bind to an operator gene and inhibit transcription Operator genes is the start of a structural gene Promoter genes indicate the structural genes that should be used to make particular mRNA at any given time They are necessary as not all genes are needed in every cell in the body.

13 Biotechnology Describe how the following can be used in the identification, prevention or treatment of hereditary diseases. Include a description of each technique DNA sequencing Profiling techniques PCR (polymerase chain reaction) Genetic probes The Human genome project Gene therapy Recombinant DNA techniques

14 DNA sequencing DNA sequencing involves identifying the precise order of nucleotide in DNA. In DNA profiling sequences are compared between individuals (DNA fingerprint or profile) Special enzymes called restriction enzymes are use to split the DNA into segments so the sequence of nucleotides can be identified. It is used to identify the genetic relationships between individuals (eg to confirm paternity) forensic science (eg identifying criminals) look for genetic disease

15 Gel electrophoresis Gel electrophoresis refers to a process that allows identification or observation of DNA patterns Uses include identification of individuals from samples (eg forensic science) genome sequences presence of inherited disease

16 Polymerase chain reaction Polymerase chain reaction (PCR) refers to the process used to replicate DNA. This increases the amount of DNA present in a sample. It is needed so that there is enough DNA present to test.

17 Genetic probes Probes are nucleic acid bases arranged in a sequence which is complementary to a sequence in the genome They usually have radioactive or chemical markers that are used to make them easily visible They can be used to detect if a genomic sequence is present, deleted or altered. They are often used to identify the presence of a gene for a disease

18 Human Genome project This is a project that set out to identify the complete sequence of nucleotides in human DNA Although the sequencing has been completed, the analysis still continues The project attempts to map locations of known genes on the chromosomes. At present the locations of about 4000 genes responsible for inherited disease have been identified Possible uses for the data collected are identification of presence of genetic diseases in individuals (diagnostic testing development of gene replacement therapies aid research into disease progression (eg identifying promoter or regulator genes)

19 Gene therapy Gene therapy involves insertion of DNA to replace faulty genes It is used when a single defective gene can be identified and a healthy one is available eg cystic fibrosis, Huntington’s disease, muscular dystrophy, diabetes Germ line therapy refers to replacement of DNA in sperm or ova and therefore aims for treatment that will be passed on to offspring. It has not been attempted due to the difficulty and the ethical considerations of changing the human genome Somatic cell gene therapy refers to replacement of DNA in non-reproductive body cells and therefore aims for treatment that will be effective in the sufferer, but can not be passed on to offspring.

20 Recombinant DNA technology This is also known as genetic engineering This refers to the processes that allow introduction of new DNA into a cell. This allows the taking of genes from one organism and placing them in the chromosomes of another producing a transgenic organism. The genes can come from individuals of the same species (eg transferring a healthy gene from one person into a person with a genetic disease = gene therapy) or from a different species (eg placing insulin producing gene into a bacteria) Uses include gene therapy, producing transgenic bacteria that can produce useful products (eg insulin). Products now being produced by this technology include hormones (eg insulin, hGH, FSH), factor VIII or vaccines Some risks and concerns associated with recombinant technology include cost, religious objections (‘tinkering with God’s work’), risk of cross species diseases or diseases resistant to treatment, unknown side effects

21 Recombinant DNA techniques Restriction enzymes are used to cut sections of DNA at specific locations and are necessary because they allow the selection of 1 gene or DNA fragment Ligation refers to joining of the two segments and is necessary because it produces 1 strand of DNA or a plasmid now containing the gene A gene for antibiotic resistance is usually added so that the bacteria with the new DNA can be identified and collected

22 Neurons What type of neuron is this? Sketch diagrams to show the differences that can be seen between this and the 2 other types of neuron Name and describe the function of structures Show the direction that a nerve impulse would travel Describe how the nerve impulse is transmitted down the neuron Describe how the nerve impulse is passed between 2 neurons

23 Neurons What type of neuron is this? Motor neuron Sketch diagrams to show the differences that can be seen between this and the 2 other types of neuron Name and describe the function of structures 1 dendrites – take impulses into the neuron 2 cell body – contains most of the organelles and carries out normal cell function 3 myelin sheath – speeds up transmission of impulses 4 axon terminals – pass message across the synapse to the next nerve or muscle Show the direction that a nerve impulse would travel Describe how the nerve impulse is transmitted down the neuron Describe how the nerve impulse is passed between 2 neurons nerve impulse

24 Neurons What type of neuron is this? Motor neuron Sketch diagrams to show the differences that can be seen between this and the 2 other types of neuron Name and describe the function of structures 1 dendrites – take impulses into the neuron 2 cell body – contains most of the organelles and carries out normal cell function 3 myelin sheath – speeds up transmission of impulses 4 axon terminals – pass message across the synapse to the next nerve or muscle Show the direction that a nerve impulse would travel nerve impulse

25 Nerve impulses Nerve impulses are transmitted down a neuron The waves of depolarisation travel down the axon until the reach the axon terminal, where they trigger the release of neurotransmitters. These chemicals act as the stimulus to the nerve at the other end of the synapse (sensory or connector neurons) or trigger a change in an effector (motor neurons) In unmyelinated fibres, the impulse travels slowly along the entire fibre. In myelinated fibres, the impulse ‘jumps’ from one node of Ranvier to the next, and therefore moves more quickly.

26 Transmission across synapses Describe how the nerve impulse is passed between 2 neurons A synapse is the gap between two neurons Messages are transmitted across the synapse by neurotransmitters which attach to receptors in the membrane of the dendrite of the next neuron. Examples of neurotransmitters include acetylcholine, adrenaline, dopamine, histamine. Enzymes remove the neurotransmitters and so clear the receptor sites for another message Messages are transmitted to muscles across the neuromuscular junction by means of neurotransmitters (usually acetylcholine)

27 Initiation of nerve impulses Explain how the nerve cell a)maintains the resting potential of its membrane b)brings about depolarization c)brings about repolarization Explain the significance of the threshold potential Explain the presence of the refractory period.

28 Initiation of nerve impulses Explain how the nerve cell a)maintains the resting potential of its membrane - Normally there is more sodium ions (Na+) on the outside and more potassium ions (K+) on the inside. Na+/K+ pumps in the membrane actively keep these ions on the correct side. b)brings about depolarization - Gated channels open in response to neurotransmitters, changes in membrane potential, or other stimuli to let in ions. This changes the difference in electrical charge (depolarisation) and triggers an impulse c)brings about repolarization - the Na+/K+ pumps in the membrane actively pumps out potassium in exchange for sodium, so that the potential is restored.

29 Initiation of nerve impulses Explain the significance of the threshold potential Any stimulation below this will not cause an impulse to be generated, and any stimulus above this will – this is called the all-or-nothing law This means that it doesn’t matter how large the stimulus is, so long as it causes a change above the threshold, an impulse will be sent. Explain the presence of the refractory period. It takes time for the membrane potential to be reset. While this is happening, the neuron can't be stimulated again

30 Central nervous system Match a label with the following structures Cerebral cortex Cerebellum Hypothalamus Pituitary gland Medulla oblongata Pons Sulcus Convolution Add labels to show Spinal cord Meninges Cranium

31 Central nervous system Match a label with the following structures Cerebral cortex Cerebellum Hypothalamus Pituitary gland Medulla oblongata Pons Sulcus Convolution Add labels to show Spinal cord Meninges Cranium Meninges

32 Control of movement Compare and contrast the nerve pathways and CNS involvement in controlling the muscle movements seen in 1.walking 2.responding to touching a hot object

33 Control of movement Compare and contrast the nerve pathways and CNS involvement in controlling the muscle movements seen in 1.Walking – conscious control – cerebrum, cerebellum, motor pathways, plus sensory input from eyes, ears and stretch receptors 2.Responding to touching a hot object Spinal reflex arc – spinal cord, sensory motor & connector neurons

34 Musculoskeletal system Name structure A Sketch diagrams to show the microscopic appearance of the tissues labelled B and C Describe how the microscopic structure of each is related to the function and characteristics of these tissues. B C

35 Musculoskeletal system Name structure A - ligament Sketch diagrams to show the microscopic appearance of the tissues labelled B and C Describe how the microscopic structure of each is related to the function and characteristics of these tissues. B – protein fibres allow for contraction, stretch and elasticity C – minerals and organisation provide strength and support B C

36 Revision 2 Describe the specific immune response to an infection Describe and explain the difference between the primary and secondary immune response Explain the effects of vaccination in terms of the immune response

37 Revision 2 Describe the specific immune response to an infection Antigen stimulation  stimulate B & T lymphocytes  cloning T-cells Helper T - activate B-cells and cytolytic T-cells Killer T - secretes chemicals and cytotoxins. These chemicals act by - killing foreign cells, attracting white blood cells, activating macrophages, sensitising lymphocytes Suppressor T - suppress B-cells and other T-cells Memory cells - store memory of antigen to provide future immunity B-cells Plasma cells - make antibody. Antibodies - inactivate/kill antigen by attaching to antigen and - preventing viruses from entering cells, inactivating toxins, destroying cell walls, causing agglutination, reducing solubility, attracting white blood cells, increasing phagocytosis, and/oractivating complement Memory cells - store memory of antigen to provide future immunity

38 Revision 2 Describe and explain the difference between the primary and secondary immune response Primary response – initial recognition and cloning of lymphocytes takes 7 – 10 days. It takes 2 -3 weeks before antibodies are present in high enough numbers to protect from disease. People usually suffer symptoms of disease during this time Explain the effects of vaccination in terms of the immune response Immunization or vaccination depends on using an antigen prepared in a relatively harmless form as the primary stimulus to develop immune memory (ie presence of memory cells). If the person is subsequently infected they have the ability to produce large amounts of antibody very quickly as memory cells for both T & B cells are present, as well as antibodies (& plasma cells). The response is usually quick enough to prevent symptoms of the disease appearing. Secondary response – initial recognition and cloning of lymphocytes is faster - 2 – 3 days. Antibody production is higher & faster days before antibodies are present in high enough numbers to protect from disease. People usually don’t suffer symptoms of disease during this time


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