B5.2 Flashcards
what is natural selection
‘survival of the fittest’. it is a process by which a species changes over time in response to the changes in the environment or competition between organisms, in order for the species to survive
what did Lamark suggest new species came from
worms - he used a giraffes neck to support this
what did Charles Darwin suggest
only the fittest will survive
what does ‘suvival of the fittest’ mean
when offspring are produced only the best dapted with the best genes will survive
where do new forms of genes come from
mutations
why did some people disagree with Darwin’s theory on natural selection
because they believed God made all of the plants and animals
in 1858, what did Wallace send to Darwin
a letter about his findings
what do people knwo Darwin more than Wallace for their influence in developing the theory of natural selection
because Darwin published a book which became famous. Darwin also had more money and opportunities and was older
what 4 observations of evolution by natural selection did Charles Darwin make
all organisms produxe more offspring tham suvive to adulthood. populations remain more of less constant in number. members of the same species show variation in characteristics. some characterstics are inherited and so are passed onto the next generation
what 2 conclusions did Charles Darwin make
all organisms are involved in a struggle for survival. some individuals are better adapted to their environment than other
what is the process for natural selection
overproduction of offspring. variety within a species (due to mutations in genetic code). selection pressure. only those organisms with the most suited characteristics survuve and reproduce. pass on their advantageous genes to their offspring. over time the population changes = evolution
what is speciation
the formation of new and distinct species in the course of evolution
what is mutation
typo in the copied DNA sequence
why are some mutations beneficial and others not in terms of an organism’s survival
mutations in the making of proteins can cause serious problems
what type of plant seeds do the Kew Millennium Seed Bank collect and conserve
endangered plants
what processes do the seed undergo in the Kew Millennium Seed Bank
reduce moisture content of seeds, clean seeds, x ray seeds, put seeds into air tight container, put seeds into seed bank, germination testing
what temperature is the seedbank at in the Kew Millennium Seed Bank
-20C
why do the Kew Millennium Seed Bank check whether a seed will germinated after cleaning
to see if the seed is alive or germinated
why grow plants in the seed bank from samples collected
for regeneration and experimenting
what threats does plant diversity face
climate change and land conversion
what is evolution
a change in the inherited characteristics of a population over many generations through a process of natural selection. evolution may result in the formation of a new species
what is speciation
when organisms become sufficiently different they will become different species
what is some evidence for evolution
the fossil record, differences in anatomy, molecular evidence, rapid changes in modern species, extinction
what is a fossil
remains of plant oranimal mineralised or changed to rock
what is the fossil record
the sequence of fossils which together show how organisms have evolved
what percentage of all species that have ever lived on the plant are now extinct
99%
what kind of species have the most similar DNA and proteins
closely related species have the most similar DNA and proteins
why do we use classification
to identify species, to predict characteristics, to find or show evolutionary links
how are animals classified
kingdom, phylum, class, order, family, genus, species
what are some advantages of species
species are capable of interbreeding naturally to produce fertile offspring. species can show variation (e.g. dogs). species have more features in common with each other that with organisms of a different species
what are hybrid species
hybrid species are produced from 2 different species but they are infertile. It is the result of breeding 2 organisms from 2 different species
what does the first part of a species name define
the first part of a species name defines the genus - this is written with a capital letter
what does the second part of a species name define
the second part of a species name defines the species - this has a lower case ketter
what do artificial classification systems use
artificial classification systems use observable features
what are some facts about artificial classification systems
they are similar in anatomical, they are physiological and behavioural, they have biochemical features, they can all successfully interbreed to produce fertile offspring
what do natural classification systems use
natural classification systems use evolutionary relationships
what is phylogeny
Phylogeny is the evolution of a genetically related group of organisms via the study of protein or gene evolution by involving the comparison of homologous sequences
