Module 4:Biodiversity Flashcards
What are the 3 main factors that affect biodiversity?
deforestation
agriculture
climate change
Name examples of how deforestation occurs
1 natural cause and 2 human causes
forest fires which are a result of lightning or extreme weathers
-directly by human action(cutting down trees)
-indirectly by acid rain which is a result of pollutants being released into the atmosphere
Name the ways that deforestation affects biodiversity
3 negative and 1 positive
4 ways
-reduces number of trees in an area
-reduces species diversity as can leave just a few species of trees intact
-reduces number of animal species in an area as it destroys their habitats and food source
-this forces them to migrate to other areas which can increase the biodiversity of other areas
What methods within agriculture affect biodiversity?
4
deforestation
removal of hedgerows
use of pesticides and herbicides
monoculture
Why is deforestation used in agriculture?
it increases the area of land available for growing crops and rearing livestock
Why is hedgerow removal used in agriculture?
2 reasons
What effect does this have on biodiversity
2 ways
-it enables them to use large machinery to help them plant , fertilise and harvest crops
-it also frees up extra land for growing crops
-reduces number of plant species in the area
-destroys habitats of many species like birds etc
Why are pesticides and herbicides used in agriculture?
pesticides-used to kill pests that eat the crops or live on the animals
herbicides are used to kill weeds as weeds compete with cultivated plant for light minerals and water
What effect do pesticides and herbicides have on biodiversity
2 for each
pesticides-reduce species diversity as they kill pest species
-they also destroy food sources for other organisms
herbicides-reduces plant diversity
can also reduce animal species diversity as it destroys food sources
What is monoculture?
Why is monoculture used in agriculture?
the yielding/growing of one specific crop or species
it allows farmers to select species that will produce a high yield meaning they will make the most profit they can
What effect does monoculture have on biodiversity
Give 2 reasons
-greatly reduces species diversity as only one species is being grown/reared
-limits variety of food source meaning area will only be able to support small number of species
What is meant by climate change?
how the characteristics of the weather in certain places have changed
What does global warming refer to?
the rise in the Earth’s mean surface temperature
If global warming continues how will it affect biodiversity?
1)what will melting of polar ice caps result in
2)rising sea levels
3)higher temps and less rainfall
4)population and lifecycle of insects
5)insects affect on plants
Give 5 examples
-melting of polar ice caps could cause extinction of plant and animal species in the area
-rising sea levels could flood low lying land which will decrease available terrestrial habitats
-higher temps and less rainfall will mean some plant species will fail to survive
-insects life cycles and populations will change as they adapt to climate change
-that could affect plants causing extinction as insects are pollinators of plants
What is the primary source of genetic diversity
Why is genetic diversity important (what does low diversity cause)?
mutations
a low diversity makes a species more susceptible to environmental changes so the whole population could easily be wiped out by an event/disease
What factors increase genetic diversity and how?
3
mutations-create new alleles
interbreeding-alleles can be transferred between the 2 populations
meiosis-the processes of crossing over and independent assortment
