Section 4 - Chapter 10: Biodiversity Flashcards
1
Q
What is biodiversity, a habitat and a community
A
- Is the variety of living organisms in an area
- A habitat is the place where an organism lives
- A community is all the populations of different species in a habitat.
2
Q
What is the binomial system
A
- All organisms are given an internationally accepted scientific name in Latin that has 2 parts
- First part (generic name) - genus. Equivalent to surname. First letter uppercase
- The second name called the specific name - species to which the organism belongs. Equivalent to first name. Lower case
- Names are always written in italics/ undelined if handwritten
- If specific name is unknown - write “sp.” Felix sp.
3
Q
What is Courtship behaviour
A
Carried out by organisms to attract a mate of the SAME species
4
Q
Why do we classify species
A
- Organise them into manageable groups
- Allows for better communication between scientists and avoids confusion
- Grouping is known as classification
5
Q
What are the 2 different forms of classification
A
- Artificial Classification
- Phylogeny Classification
6
Q
What is Artificial Classification
A
- Grouping organisms based on features that are useful at the time
- e.g colour, size, leaf shape
- These are described as analogous characteristics where they have the same function but don’t have the same evolutionary origins (wings of butterfly and bird)
7
Q
What is Phylogenetic Classfication
A
- Based upon evolutionary relationships between organisms and their ancestors
- Classifies species into groups using shared “homologous” features derived from their ancestors
Relationships in P.C are partly based on homologous characteristics. Have similar evolutionary origin regardless of function. Arm of a human, leg of a horse. have same basic structure and evolutionary origins and therefore homologous
- Arranges the groups into a hieracy, in which the groups are contained within larger composite groups with no overlap
8
Q
What is Taxonomy
A
- Taxaonomy is the science of classification. It involves naming organisms and organising groups
- This makes it easier to identify and study them.
- Thare are 8 levels of groups used to classify organisms. - taxa Each group a taxon
9
Q
What are the 3 domains
A
- Eukarya
- Bacteria
- Archaea
10
Q
What is the Bacteria Domain
A
- Group of single-celled organisms
- no membrane-bound organelles
- Unicellular
- Ribosomes = 70S
- Cell walls= murein
- Single loop of DNA no histones
11
Q
What is Archaea
A
- Are a group of single-celled prokaryotes that were originally classified as bacteria which they resemble in appearance. They differ because
- Their genes/protein synthesis similar to eukaryotes
- Membranes have fatty acids attached to glycerol
- No murein
- More complex form of RNA polymerase
12
Q
What are Eukarya and what are the 4 kingdoms it splits into
A
- Group of organsisms made up of one or more eukaryotic cells. Their features are:
- Have membrane-bound organelles
- Have membranes containing fatty acid chains attached to glycerol by ester bonds
- Not all have cell walls - no murein
- Ribosomes are larger 80S
- Protoctista, Fungi, Plantae and Animalia
13
Q
What is the order of the groups of classification. They names of the taxa.
A
- Domain - delicious
- Kingdom - King
- Phylum - Prawn
- Class - Curry
- Order - Or
- Family - Fat
- Genus - Greasy
- Species - Sausages
14
Q
What is phlogeny
A
- Phylogeny is the study of the evolutionary history of groups of organisms
- Phylogeny tells us who is related to whom and how closely related they are
- All organisms have evolved from shared common ancestors - shown using phylogenetic tree
15
Q
How can Biodiversity be measured.
A
Species Diversity
- Number of species in a particular area
- 2 communities could have the same number of species but the proportions of each species can vary
Index of Diversity
- Calculated using an equation that takes both the number of species in a community (species richness) and the abundance of each species
16
Q
What are the 3 components of biodiversity
A
- Species Diversity:
- The number of different species and individuals of each species in one area (community)
- Genetic Diversity:
- All of the alleles/variety of alleles/genes by individyals that make up the species
- Ecosystem Diversity:
- The range of different habitats within an area.
17
Q
What is the impact of agriculture on Biodiversity. What do the farmers do that can reduce species diversity
A
- Farmers select for species for particular qualities. As a result number of species and variety of alleles is reduced to the few desired species.
- Number of desirable individuals needs to be large. If most of the area is taken by 1 species , smaller areas for others. Have to compete
- Pesticides are used to exclude species because they compete for light, water, mineral and food.
- Overall reduces species diversity
18
Q
What are the practices that have directly removed habitats and reduced species divesity + include indirect actions taken
A
- Removal of hedgerows
- Creating monocultures - removing a natural meadow for 1 crop
- Filling in ponds and draining marsh and other wetland
- Over-grazing of land - preventing regeneration of woodland
- Using pesticides and fertilisers (indirect)
- Effluent waste/sewage escaping into water (indirect)
- Lack of crop rotation (indirect)
19
Q
A
20
Q
Name some of the conservation techniques that can increase species diversity
A
- Maintain existing hedgerows
- Plant hedges instead of fences
- Maintain existing ponds
- Leave wet corners of fields
- Plant native trees
- Reduce the use of pesticides
- Use organic not inorganic
- Use crop rotation
- User intercropping rather than herbicides to control weeds and other pests
21
Q
What are the different ways to compare the evolutionary relationship of species
A
- By observable characteristics
- By the DNA base sequences
- By the base sequence of mRNA
- By the amino acids sequence in amino acids
22
Q
How can the comparison of observable characteristics be carried out
A
- This method is based on the fact that ecah observable characteristic is determined by the gene or genes
- The variety within a characteristic depends on the number and variety of alleles of that gene
- This has limitations: large number are coded by more than 1 gene (polygenic). Can vary continuously. Characteristics can be modified by the environment
- This is replaced by directly observing DNA sequences themeselves
23
Q
How is comparison of DNA base sequences carried out
A
- Can read the base sequences of the DNA of any organism. Can determine exact order of nucleotides. Used by machines
- Each nucleotide base is tagged with a colour (adenine green, thymine red, cytosine blue, guanine yellow.
- Produces a series of coloured bands - represent nucleotides. Can sample and compare to see how diverse
- This helps determine evolutionary relationship between species. When a new species arises from another species. DNA = similar
24
Q
How is Comparison of the base sequence of mRNA carried out
A
- mRNA is coded for by DNA, mRNA is complementary to the DNA strand it was made from
- Therefore we can use DNA as a measure of genetic diversity by comparing species mRNA
25
Q
How is comparison of amino acids in sequences of proteins carried out
A
- The sequence of amino acids in proteins is determined by mRNA, which is then determined by DNA
- Genetic Diversity can be measured by comparing amino acid sequences of their proteins
- The similarity of the sequences will reflect how closely related they are.
- Sequences are compared by counting the similarities or differences
26
Q
What does Courtship behaviour allow individuals to do
A
- Recognise members of their own species - mating takes place between members of their own species
- Identify a mate that is capable and mature to breed - both need to be sexually mature and fertile.
- For a pair bond - lead to successful mating and raising of offspring
- Synchronise mating - it takes place when the egg and sperm is most likely to meet
- Become able to breed by bringing a member of the opposite sex into a phsiological state that allows for breeding
