B3 Flashcards
what is interdependence?
the feeding relationship of organisms in a habitat
what is detritus?
.partly decayed material
what is detritivores?
eg. earth worms and woodlice that break down detritus
how is carbon returned to the air?
.as a product of respiration
.through decomposition of dead organisms
.by combustion of organic materials
how do plants take up nitrogen?
through their roots, in the form of nitrogen compounds which are then converted into protines
what are the two ways in which nitrogen enters the nitrogen cycle ?
. nitrogen molecules in the air are split by lightning. atoms then combine with oxygen in the air and washed into the soil
.nitrogen fixing bacteria is found in the soil and the roots of plants which is then converted into nitrogen
how does nitrogen leave the cycle?
when denitrifying bacteria converts nitrates in the soil into nitrogen gas. this is called denitrification
what is biotic index?
observations done on some living indicators that can give us information about levels of pollution and environmental change
what is natural selection?
the individuals with advantages that pass on their genes and is selecting the best and more adapted
what are some factors that affect the rate at which evolution takes place?
.when the environment changes only the best can adapt or readapt will survive
.if organisms become isolated they will not be able to reproduce
what are some evidence found that proves the theory of evolution through organisms ?
.examining fossil records
.observing similarities and differences in physics features
.analysing DNA sequences
what is some of the evidence to support evolution?
.the simplest organisms are found in the earliest rocks
.more recent fossils have features that look like developments or adaptations of those older organisms
.DNA of todays organisms has confirmed predictions made from the fossil records including when branches in the tree life occurs
what did landmark say?
he suggested that animals acquired characteristics during their life time that were then passed on to their off spring
How are organisms classified?
.a kingdom is a large group with many organisms but fewer characteristics in common
.moving down from the kingdom, the groups get smaller ad have fewer organisms with more characteristics in common
the level identifying the individual type of organism in the species
why is intensive monoculture crop production?
.not sustainable
. just grow one crop
.sprayed with pesticides
.removing hedgerows to create more space
