inheritance, variation and evolution

Alternative transcript:

involves one parent so there is no mixing of genetic material offspring are identical Clones. · no variation. mitosis or binary fission advantages · only one parent is needed process is rapid disadvantages no 240 genetic meiosis gametes= Bex cells that have half the genetic. material of a normal cell (haploid) each arm · Cell divides again. variation Suseptible to new diseases less chance of adapting Steps of meiosis · replicate ana • Chromosome pairs line up in the centre • Chromosomes pull apart and cell splits in half A Chromosomes line up in the middle is pulled apart Gregor Mendel founding father of genetics • experimented on pea plants by crossbreeding them together. • found that hereditory units could be recessive ar dominant - his work (koba was enx critisised at the time because DNA had not yet been discovered Recessive = only expressed if the organism. gets the allele from both parents genetic engineering • the process of taking a gene out of an organism with a desirable characteristic and transtering it into another organism so that. it develops the same trait. • the new organism is genetically modified because the organisms genome has been. altered. •this isn't limited to organisms of the same species examples: · Sheep modified to produce drugs in their. mill bacteria modified to produce insulin • Crops modified to be resistant to diseases, insects and herbicides. Gene therapy -giving a person with an inherited disorder the healthy version of their faulty gene - hard to transfer the new gene to every cell. in order to fix the problem. - a solution to this is transtering the gene at the embryo stage of development so that the healthy gene is passed on to other cells transfering genes 1. cut out the desired gene using enzymes 2. Insert into a vector 3. introduce vector to chasen organism 4. Organism will start producing the protein. that the gene codes for animal Cloning 1. take an egg cell from a donor temale and remove the nucleus 2 take an adult body cell from the chosen Organism and remove the nucleus 3. put egg cell 4. Simulate the cell via a small electric shock it will then act as a zygoat and divide this nucleus into the enucleated by mitosis, forming an embryo 3. implant embryo onto the uterus of a Surrogate mother. It will then develop. Cloning transgenic animals to produce human proteins Scientists are now able to put human genes into the ona of other organisms. this means the animal is transgenic Scientists often clone transgenic animals. Cloning by embryo transplants 1. pick a male and female organism with desirable Characteristics 2. take the sperm and fertilise the egg 3. let the zygote develop into an embryo 4. Seperate the embryo into lots of smaller ones 5. put into Surrogate mother 6. Oftspring will be identical Clones Cloning plants - Cuttings 1. Cut off a small part of a plant shoot 2. place cutting in soil with nutrients and hormones. 3. Gutting will grow to be a clone Micro propagation 1. take small pieces of plant tissue from the tips or stems. 2. Sterilise them to remove any microorganism 3. place in agar and allow to grow 4. transfer the calluses into soil where they can grow into plantlets. mutations a mutation is a change in the dna base sequence. This happens spontaneously in our cells when ona is duplicated Carcinogens and radiation increase rish. it a mutation occours, the sequence of amino acide would be different so it would Code for a different protein. y the protein- was an enzyme the mutation may. change the shape of the active site so it cannot bind with the substrate Bubstitution = one base is changed for another random base. Insertion = an extra base is added removed from the deletion = a base is Sequence Inherited disorders = a group of conditions. in alleles and so is inherited passed on From parents polydactyly • babies are born or toes caused by a dominant allele with extra fingers. Cystic fibrosis. Causes sticky mucus to be released in lungs and pancreas Caused by a recessive allell Fossils things left behind by long dead organisms Such as Skeletons, entire organisms that haun't decayed or impressions in ground -Formation: 1. gradual replacement that it is n 2. Casts 3. impressions 4. peservation extinction = no individuals of that species. remain reasons for extinction. - enviroment changes too quickly habitat destruction. introduction of new preditors. human hunting. new diseases catastrophic event antibiotic resistance. 1 bacteria have a mutation that make them less affected by antibiotics 2. resistant bacteria survives and reproduces rapidly - Spreading the gene 3 people pass on resistant bacteria. to others Superbug = bacteria that is resistant to many types of antibiotic Carl linnaeus = linneam system Kingdom → phylum → Class → order → Family & Speciese genus species. Carl wose = three domain System Eukaryota bacteria archaea.