Biodiversity Flashcards
what is a species?
can interbreed to produce fertile offspring’s and Do not normally interbreed with any other group of organisms. occupy the same ecological niche. will be similar in terms of DNA, physical attributes etc
what ecological niche?
An ecological niche is the role and position a species has in its environment e.g. how it gets food and shelter, how it survives, and how it reproduces
what is a hybrid?
give an example?
Different species can sometimes interbreed to produce hybrid offspring. The parent organisms are still considered separate species because their offspring are infertile. liger – the infertile offspring of a male lion and a female tiger.
what is courtship?
Animal activity that results in mating and reproduction.
how can individuals of the same species recognise each other?
by the way they act.
but also they can recognise each other by looks
explain the difference in courtship between human and animals?
Humans are unusual in that mating is often carried out without the intention of creating fertile offspring!
females only reproduce at..? so..?
females only reproduce eggs at a certain time so courtship behaviour is important so that the male is aware that if the female is not in a receptive stage then she can provide an accurate response in order for the male to find another receptive partner
explain why courtship is important?
Courtship is important as it acts as an isolating mechanism to prevent different species from interbreeding. Also helps to ensure successful mating between members of the same species This means that fertile offspring are produced. The species survives!
courtship enables individuals to?
- recognise members of their own species
- identify a mate that is capable of breeding
- form a pair bond that will lead to successful mating and raising of offspring
- synchronise mating so will only take place when there is a maximum possibility of egg and sperm meeting
- become able to breed by bring a member of the opposite sex into the psychological state that allows breeding to occur
what do females look for in mating
Choose a strong and healthy mate that is capable of breeding
Elaborate courtship rituals help strengthen pair bonds that may last through the raising of the young or longer. Why is that important?
result in a bond forming between two animals that can, in many cases, last a lifetime. This bond becomes evolutionarily advantageous in species where both parents must care for the young by increasing the likelihood that the parents will stay together after mating.
examples of courtship?
explain what is meant by species are specific?
helps to ensure successful mating between members of the same species This means that fertile offspring are produced The species survives!
what are pheromones?
some female insects use this to attract males
what is a sign stimulus?
Sign stimulus (releaser) The essential feature of a stimulus, which is necessary to get a response.
why do we have a classification system?
because there are millions of species and it helps us to Understand relationships between organisms and keep track of changes
what is phylogeny?
the study of how closely related organisms are in terms of evolution
what is a hierarchy?
smaller groups are placed within larger groups. There is no overlap between groups.
how are organisms grouped?
- common features
- shared evolutionary history
what are the 3 domains?
- bacteria
- archaea
- eukarya
what is the order of classification? name each group.
DOMAIN
KINGDOM
PHYLUM
CLASS
ORDER
FAMILY
GENUS
SPECIES
what is each group called?
a taxon
each species is universally identified by a binomial name which consists of?
the name of the genus and species.
DNA, proteins and classification
after science, comparisons can be made from..?
by direct examinations of their:
- DNA
- or mRNA
- proteins encoded by their DNA
explain the advantage of this?
This allows better comparisons and understanding of evolutionary relationships
How can comparison of base sequences be used to investigate how closely related organisms are?
why do distant related organisms usually show fewer similarities?
The more closely related the species the higher the degree of similarity in the bases sequences.
Distantly related organisms usually show fewer similarities.
This is because mutations accumulate over time.
what is DNA hybridisation?
A technique used to determine similarities between DNA from different organisms.
explain the process of hybridisation.
- DNA from two species mixed
- When DNA is heated it separates into 2 strands by breaking hydrogen bonds
- cooling of the strands allow complimentary bases/strands to join by hydrogen bonding
- non-complimentary bases that can not pair and join together left unpaired
how can we identify if two species are closely related?
if the hybrid strands where most bases are paired up. a higher temperature is needed to separate them.
how can we identify if two species are distantly related?
if the hybrid strands, where most of the bases are not paired up/ few are paired up and a lower temperature is needed to separate them
how can we use proteins to classify how closely related two species are?
give an example?
The sequence of amino acids in proteins is
determined by DNA. The degree of similarity between the amino acid sequence (primary structure) of the same protein in 2 species will show how closely related they are.
E.g. Cytochrome C, found in the mitochondria
Humans and chimpanzees = exact same sequence
how can immunological comparisons classify how related two species are?
given an example?
Antibodies of 1 species will respond to specific antigen on proteins of another.
E.g. Antigens on the albumin
protein found in blood serum
explain in detail how this would work?
using a rabbit as an example.
- rabbit injected with pure human albumin
- rabbit produces antibodies against human albumin
- anti-human antibodies collected and purified
- results - human albumin forms a very dense precipitate
- chimpanzee albumin produces less dense precipitate
what are some classification sources of evidence?
Evolutionary history/phylogeny
Similar features
Biochemical differences e.g. DNA, proteins,
mRNA
Number and form of chromosomes
Fossil record
what is biodiversity?
Biodiversity is a measure of how varied an ecosystem is. It can be measured in terms of genes, species or habitats.
what is genetic diversity?
Genetic diversity is a measure of how many genetic variations there are between individuals of a particular species, or between different species.
what is species diversity?
Species diversity is a measure of how many
different species are present in an area, and how many individuals of these species there are.
what is habitat diversity?
Habitat diversity is a measure of how many different habitats are present in an area.
where would there be an expected low level of diversity?
mown lawn
what is a species?
A group of organisms that:
- share common characteristics
- can interbreed
- produce fertile offspring.
- Have a common ancestor
what is a habitat?
A habitat is the area in which a species lives.
what is the population?
A population is group of organisms of the same species living in a habitat.
why do habitats usually only contain several species?
The habitats of different populations often overlap, so any one habitat usually contains several species.
what is a community?
A community is all the populations of all the species within a particular habitat.
what are biodiversity hotspots?
Biodiversity hotspots are regions of the world that have a particularly high level of biodiversity but are threatened with destruction.
why is biodiversity important?
- not low biodiversity but the loss of biodiversity. causes
- Ecosystem disruption can ultimately have
a significant impact on humans.
Why might biodiversity decrease?
due to human activity, such as land use changes, pollution and climate change, poor water quality, chemical and waste contamination
What specific problems can loss of biodiversity create?
changes in land and sea use; direct exploitation of natural resources; climate change; pollution and invasive species.
why do we measure biodiversity?
It enables comparisons to be made:
- between different areas
- in the same area at different times
what is meant by species richness?
This is the number of different types of species in a particular area. The greater the number of species, the ‘richer’ the area.
what is species evenness?
This is a comparison of the size of the population (i.e. the number of individuals) of different species within a particular area.
when does species diversity increase?
Species diversity within an area increases as both species richness and species evenness increases.
how do we measure Sampson’s index of diversity?
what do each of the letters represent?
D = ∑ n(n – 1) /N(N – 1)
N = the total number of organisms of all species
n = total number of organisms of a particular species
D = Simpson’s diversity index
what is the lowest possible value of D?
1
impact of biodiversity on farming
explain how farming increases the productivity?
why has it increased?
PRODUCTIVITY: the amount of food we get per hectare
Increased due to:
Fertilisers, pesticides, selective breeding, GM crops etc.
explain how farming is efficient?
ratio between energy given out of a system (in terms of food) and energy put in
what is conservation?
Conservation is the study and protection of biodiversity and natural resources.
explain how removal of hedgerows has an impact on biodiversity?
how is this an advantage to farmers?
habitats destroyed, food webs can fall apart, diseases can spread rapidly, and crops can become more susceptible to pests.
more land to grow crops = more money/profits
what is monculture?
only growing one variety/species of crop
what are the pros and cons of selective breeding?
pros: creates crops with desirable
characteristics, leading to higher yields and less wastage.
con: lack of genetic diversity can make the crop highly susceptible to pests and diseases.
explain the impact of biodiversity?
farmers - plants not eaten by insects, more consumers more profits
biodiversity - toxic effect on organism
what are some conservation measures which can be used to reduce the impact of loss of biodiversity?
- use organic fertilizers instead of inorganic
- maintain hedgerows by an A-shape provides a better habitat than a rectangular one
- maintain existing ponds and possibly create new ones
FINISH
