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Revision

Revision. Composition of blood Heart Smoking and the lungs Circulation and blood vessels Reproductive system Menstrual cycle and pregnancy Genes and genetic crosses. Plant transport – vessels and transpiration Plant reproduction Natural selection Selective breeding

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Revision

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  1. Revision • Composition of blood • Heart • Smoking and the lungs • Circulation and blood vessels • Reproductive system • Menstrual cycle and pregnancy • Genes and genetic crosses • Plant transport – vessels and transpiration • Plant reproduction • Natural selection • Selective breeding • Cloning – animals and plants (micro-propagation) • Genetic engineering

  2. Blood • What do these blood components do? • Plasma-It is mostly water (90% by volume) and contains dissolved proteins, glucose, clotting factors, mineral ions, hormones and carbon dioxide (plasma being the main way for excretory product transportation) • White Blood cells & Platelets-are cells of the immune system defending the body against both infectious disease and foreign materials • Red blood Cells-are the most common type of blood cell and the vertebrate organism's principal means of delivering oxygen

  3. Circulatory system • You should know the names of the major arteries and veins • You should be able to draw a simple labelled diagram of: • Artery – • Vein – • Capillary – Inner layer of lining (endothelial) cells Outer layer Made of Fibrous Cells Middle layer containing smooth muscle fibres and elastic fibres Valves prevent the backflow of blood, carries blood to the heart. Endothelial cells

  4. Heart • Label to revise structure • Remember: • Job of valves • Where each side of the heart pumps blood to • What pressures roughly would be like in each side • Replace letters with correct word: the CA supplies the HM with O and G and if blocked by F means the HM receives less O, so uses AR, producing LA causing death of cells.

  5. Reproductive systems Fallopian tube Ovary You should be able to label these parts for females and males… You’d also be expected to know where fertilisation takes place (label with an F) and also where implantation takes place (label with an I) Uterus Cervix Vagina Bladder Seminal Vesicle Sperm Duct Penis Urethra Testis Foreskin Scrotum

  6. Menstrual cycle • What’s important… • Ovarian hormones & function: 1) 2) • Pituitary hormones & function: 1) 2) • What would happen to progesterone levels after fertilisation? • What would oestrogen levels do during menstruation? • Which hormone peaks on which day to release the egg?

  7. Placenta • You should be able to: • Say why mother and baby blood doesn’t mix • How nutrients do get passed across the placenta • Name the nutrients:

  8. Smoking:Cigarettes – what’s in them?Effect on HEART & LUNGS Tar Cancer Carcinogens Cilia Mucus Bacteria Infection Alveoli Nicotine Bronchitis Emphysema Fat/cholesterol Coronary arteries Surface area Gas exchange Oxygen Anaerobic respiration Lactic acid Increased heart rate Hardening of arteries Increased blood pressure

  9. Inheritance and DNA • You are expected to be able to: • Carry out a punnett square genetic cross e.g. • Work out genes and alleles in a family pedigree e.g. Key words: Gene Allele Dominant Recessive Homozygous Heterozygous Gametes Genotype Phenotype Sex chromosomes Double helix Nucleotide (higher tier only) Bases (higher tier only) Co-dominant (higher tier only) Test cross (higher tier only)

  10. Transpiration • Definition = the e________ of w____ from the leaf • Looking at the diagram… • How is water encouraged into the root hair cell in the 1st place? • What layer is transpiration and evaporation taking place in the leaf? • For each factor, state if it would increase or decrease transpiration AND why. • High temperature • High humidity • Low light levels • Tiny hairs on the leaf surface • Windy conditions 4) Which apparatus could you use to measure transpiration rates?

  11. Plant transport Which vessel is dead? What should the diagram say instead of ‘food’ in the phloem vessel? What does lignin do? It is _ _ _ _ _ p _ _ _ _ and adds _ _ _ _ n _ _ _ to the plant What is the name given to the bundle you find these vessels in?

  12. Plant reproduction Looking at the top right diagram from a student, there are at least 3 corrections/additions you could make…what are they? Looking at the bottom right diagram showing self-pollination (both types but you are not expected to know their names)… Q: What is the genetic disadvantage to using self-pollination? Q: What do plants from self-pollination often look like compared to the parent? You are also required to know the physical differences between wind and insect pollinated plants and what type of seed dispersal plants use

  13. Natural Selection • Individuals in a population show variation to start with • Mutations produce new alleles • These new alleles give the organism an increased chance of survival, making them better adapted to their environment • This could be: better camouflage, stronger, faster, resistance to disease • Either way, they are more likely to survive (not get eaten) and more likely to reproduce • So they pass these alleles to their offspring • Those less well adapted die out • The frequency of the beneficial alleles go up in the population over time An example shown in cartoon form for the bacterium Helicobacter pylori: To structure an answer, re-order the stages on the right:

  14. Selective breeding: for a decent answer, re-order the steps on the right… • Repeat over many generations • Select offspring with desirable characteristics • Breed parent organisms together • Breed only these together • Select desirable characteristics in parents Examples in your book include wheat for decreased stem length, cattle for milk yield and muscle mass

  15. Cloning: animals • Using the diagram, state: • What do you do to the donor egg at 1? • What type of nucleus is removed? • Which two pieces of apparatus will you need to carry this job out? 4. What type of cell division happens at 3? 5. How is this stimulated at 2? 6. Where is the embryo put into 4? 7. What is the name of the sheep below 4? 1 2 3 4

  16. Cloning: plants = micro-propagation • Correct the mistakes and state how many there are: • Take grabbings called axeplants and wash them to kill bacteria. Transfer to Rowntree’s jelly and add sleep hormones/regulators and essential minerals. When plantlets grow roots and shoots, transfer to mud. You could use a purplehouse and control conditions such as light, heat, water, CO2, humidity. Each plant will be genetically different to the parent. This method is great at producing small quantities of plants, all cloned with an undesirable characteristic. NB. A Callus is often mentioned here – this is a dividing ball of cells…an ideal place to extract cells for tissue culture that will each grow up to be a new plant Number of mistakes =

  17. Genetic Engineering The basic method: 2 of the 3 ways to modify plants Using a virus as a vector is the other e.g. the tobacco mosaic virus which infects, surprisingly, the tobacco plant ● Plasmid & bacteria/virus are acting as vectors ● Restriction endonuclease = cut ● Sticky ends left behind on the plasmid & gene ● Ligase enzyme = join DNA back together Same principle in animal and plant cells but you need to think about the way you would insert the recombinant plasmid into the organism – this is very different for plants and animals. Agrobacterium can be used to infect some plants, not others, so then you’d use a virus (e.g. tobacco mosaic virus) or gene gun Inhalers/nebulisers or viruses that attack lung cells are 1 way we introduce the recombinant plasmid to treat a lung problem in humans We also use transgenic organisms, e.g. using pigs to grow human insulin. Transgenic = ____________________________________

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