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Biology AQA A Level > Diversity Ch.9 , 10 > Flashcards

Diversity Ch.9 , 10 Flashcards

1
Q

Population

A

A group of individuals of the same species that live in the same place and can be interbreed

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2
Q

Habitat

A

The place where an organism normally lives and which is characterised by physical conditions and the type of other organisms present

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3
Q

Species

A

A group of similar organisms that can breed to produce fertile offspring

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4
Q

What indicates genetic diversity within a species

A

The total number of different alleles

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5
Q

State two types of selection

A

Directional selection and Stabilising selection

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6
Q

What is Directional selection

A

When the selection favours individuals that have phenotype that fall the the right or left of the mean. (The extreme)

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7
Q

What it Stabilising Selection

A

When the environment remains stable the individuals with phenotype closest to the mean are favoured

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8
Q

Species are called by two of their taxon names, which two and in which order?

A

1st- Genus

2nd- Species

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9
Q

What is the name of the naming system

A

Binomial System

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10
Q

Classification

A

The process of grouping organsims

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11
Q

What is phylogenetic classification

A

The classification is based on evolutionary relationships between organisms and ancestors

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12
Q

What is a homologous characteristic

A

Similar evolutionary origins regardless of function

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13
Q

Hierarchy

A

Groups within groups that do not overlap

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14
Q

What is the Taxon ranking. Biggest to smallest

A

Domain, Kingdom, PHYLUM, CLASS, ORDER, FAMILY, genus, species

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15
Q

Speciation

A

The formation of a new species derived from another due to evolution. Normally occurs due to an event, e.g separated into different locations

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16
Q

What is the importance of courtship behaviour

A

Recognition of members of their own species
To identify when member is fertile
Successful mating.
Can allow for pair bond

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17
Q

What leads to genetic diversity

A

Different alleles, caused by mutation

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18
Q

Genetic Diversity

A

The variety of genes possessed by the one population of a species

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19
Q

Species Diversity

A

The number of different species and number within each species within a community

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20
Q

Biodiversity

A

The range and variety of genes, species and habitats within a particular region

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21
Q

Ecosystem Diversity

A

The range of different habitats

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22
Q

Species Richness

A

the number of different species in a particular area/ in a community

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23
Q

Species eveness

A

the number of individuals in each species within a particular area

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24
Q

What reduces index diversity

A

Fewer habitat
Fewer food source
Fewer variety of plants, species…

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25
Q

What is monoculture

A

Producing one type of crop often genetically identical.

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26
Q

How can you compare the genetic diversity?

A

1) the frequency of measurable or observable characteristics.
2) Compare base sequence of DNA (fluroscent dye)
3) Compare amino acid sequence in the same protein
4) Compare base sequence of mRNA, so only coding DNA.
5) Immunological comparison of protein.

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27
Q

Inter- specific

A

Differences between species

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28
Q

Intra- specific

A

Differences within a species

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29
Q

Sampling

A

Selecting a group of organisms to study which are representative of the population.

30
Q

What does an overlap in standard deviation mean?

A

The data is due to chance and is not real.

31
Q

Mutation

A

A sudden change in the amount or the arrangement of the genetic material in the cell.

32
Q

What’s substitution mutation?

A

A nucleotide in a DNA molecule is replaced by another nucleotide that has a different base.

33
Q

What’s the effect of a substitution mutation?

A

The triplet codon changes. If the new codon codes for a new amino acid the tertiary structure of the protein could change making a non-functional protein.

34
Q

What is a deletion mutation and what’s it’s effect?

A

One nucleotide is removed leading to a frame shift. Every codon after has changed so the amino acid sequence has changed. This is more likely to lead to faulty proteins.

35
Q

What is a insertion mutation and what’s it’s effect?

A

One nucleotide is inserted leading to a frame shift. Every codon after has changed so the amino acid sequence has changed. This is more likely to lead to faulty proteins.

36
Q

What is a chromosome mutation?

A

Changes in the structure or number of whole chromosomes

37
Q

What is a mutagenic agent?

A

Something that increases the rate of mutations

38
Q

Give examples of mutagenic agents

A

Radiation, chemicals (Carcinogens) and infectious agents (HPV and bacteria).

39
Q

What happens in meiosis?

A

Produces four genetically different haploid daughter cells known as gametes.

40
Q

What is the importance of meiosis?

A

To maintain a constant number of chromosomes in the species. To produce genetic variation which means the species is more likely to survive an environmental change

41
Q

What happens in each stage of meiosis 1 ?

A

Prophase 1 - c-somes condense and nuclear envelope disappears, and c-somes cross-over.
Metaphase 1 - Homologous c-some pair up randomly at the equator, spindle fibre connects to centromere.
Anaphase 1 - Spindle fibres contract pulling homologous pairs to opposite sides of the cell.
Telophase 1 - nuclear envelop develops around each set of chromosomes, spindle fibre disintegrates

42
Q

What is cross over/ recombination?

A

At prophase 1 when homologous c-somes are paired up, portions of chromatids break off and recombine with the chromatid of its homologous partner.

43
Q

What would happen without crossing over?

A

In meiosis there would only be two types if genetically different daughter cells, with cross-over there is four.

44
Q

What happens in each stage of meiosis 2?

A

Prophase 2 - nuclear envelope disappears and spindle fibres form
Metaphase 2 - 23 c-some align in the equator and spindle fibre connects to centromere.
Anaphase 2 - Spindle fibre contracts and each chromatid is pulled to the opposite side
Telophase 2 - Each cell divides again producing four haploid cells.

45
Q

Give two ways in which genetic variation occurs in meiosis?

A

Independent segregation of homologous chromosomes, crossing over between homologous chromosomes.

46
Q

What is independent segregation?

A

When homologous chromosomes pair up, they do so randomly. This means it is random which daughter cells gets which chromosome.

47
Q

In meiosis how would you calculate the number of possible combinations of chromosomes for each daughter cell

A

2^n where n is the number of homologous chromosomes so the haploid number.

48
Q

how would you calculate the possible number of combinations of chromosomes following random fertilisation of two gametes?

A

(2^n)^2

49
Q

What is genetic diversity?

A

the number of different alleles of genes in a

population.

50
Q

Why is genetic diversity important?

A

It makes it more likely that some of the population will survive when there is an environmental change.

51
Q

Describe the process of natural selection

A
  • Within a population there will be a gene pool
  • Random mutations occur which are usually harmful but occasionally are advantageous.
  • Better adapted means more likely to successfully reproduce.
  • Advantageous allele will be inherited by next generation
  • Over generations the frequency of the new allele increases.
52
Q

Give an example of directional selection

A

Antibiotic resistance

53
Q

Give an example of stabilising selection

A

Birth weight of babies.

54
Q

Why is it good to use a logarithmic scale for bacteria culture?

A

Because there is a large number of bacteria in order to fix it all on the same graph and compare.

55
Q

Describe aseptic techniques

A
  • Blue flame
  • Open everything in blue flame
  • Pass bottles over the flame and the hoop.
56
Q

What is a group within the phylogenetic classification system called?

A

Taxon or Taxa plural

57
Q

What is the acronym for the hierarchy of classification

A

Dirty Kinky People Can Often Find Good Sex

58
Q

How would your write the name of a species?

A

Genus with a capital letter, then species with lower case letter.

59
Q

Why is defining a species based on observable characteristics not a good idea?

A
  • Species evolve and change

- Can be wide variation within a species

60
Q

Why is defining a species based on their ability to produce fertile offspring not a good idea?

A
  • Some species may be extinct already so can’t prove they were same species
  • Some species may never/rarely reproduce
  • Populations may be isolated from each other so never interbreed.
  • Some organisms are sterile.
61
Q

Why can a mule with 63 chromosomes not reproduce but still grows?

A

Because there is an odd number of chromosomes it mean homologous chromosomes cannot pair up in meiosis, however can still mitosis occur.

62
Q

What is index diversity used for?

A

To describe the relationship between the number of

species in a community and the number of individuals in each species.

63
Q

What is the symbol for index diversity?

A

d

64
Q

What is the formula for index diversity?

A

d= N(N-1) / sum of n(n-1)

65
Q

What does N and n stand for in the index diversity?

A

N the total number of organisms,

n the number of organisms in each species

66
Q

Why does farming reduce biodiversity?

A

It normal reduces the variety of habitat, food and species because they use pesticides, fertilisers (competition), crop only one species…

67
Q

Why is sampling not always representative?

A

1) Biased sampling (deliberately or accidentally)

2) Chance that the samples you chose were not representative.

68
Q

Give a method for random sampling

A

1) Use to tape measures to form a grid.
2) Use random numbers generated by a computer to form random co-ordinates
3) Take sample from the co-ordinate (use quadrant…)

69
Q

How can you remove chance from the sampling process?

A

1) Use big sample size so anomalies have less impact on the average.
2) Analyse the data with statistical tests.

70
Q

What is standard deviation?

A

The range of values either side of the mean.

71
Q

From a graph how could you tell it’s a skewed distribution?

A

The Mode, mean and median will not be at the same point.

Biology AQA A Level (15 decks)

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