variation and genetics and evolution- CH14 & 15

differences in the characteristics of individuals in a population

variation

causes of variation

inheritance, environment

gregor mendel

discovered some characteristics are more dominant than others

jean baptise lamarck

thought it a parents had a change to their body in their lifetime that it would be passed on (wrong according to darwinism)

alfred russel wallace

had same ideas as darwin about evolution by natural selection

speciation

formation a of new and distinct species when they are separated and have different conditions

species

organisms that can interbreed to produce fertile offspring

natural disasters, speciatin, changes in the environment, new predator, diseases, competition

reasons for extinction

the right conditions are rare, many still to be found, destroyed by earthquakes, early forms of life were soft bodied so left little fossil trace

reasons for incomplete fossil record

preservation

when animals don’t decay after they die

cast and impressions

preserves traces of the animal such as footprints

gradual mineral replacement

hard shell is replaced by minerals that turn into rock

permanent loss of all members of a species from the wild

extinction

don’t overprescribe, complete the course, don’t use on animals, don’t prescribe for non-serious conditions

preventing antibiotic resistance

selective breeding

process where humans breed plants and animals to get particular characteristics

animal rights, less diversity, inbreeding

disadvantages of selective breeding

larger yields, no specialist kit needed

advantages of selective breeding

genetic engineering

process that modifies the genome of an organism by introducing a gene from another organism to give desired characteristics

insulin, improving crop yield, longer shelf life, more resistance to disease

uses of genetic engineering

clone

an individual that has been produced by asexual reproduction so is genetically identical to the parent

produces thousands of offspring with ideal characteristics, fast, cheap

advantages of cloning plants

avoids extinction, maintains genetic breeding however reduces the gene pool

advantages of cloning animals

classification

organising living organisms into groups based on characteristics and structure

classification order

kingdom, phylum, class, order, family, genus, species

carl woese

discovered third domain of life- archaea

archaea

live in extremophiles, some without oxygen