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Biology Definitions Unit 3 and 4 > Unit 3 Definitions > Flashcards

Unit 3 Definitions Flashcards

1
Q

A group of similar organisms whose members can interbreed in their natural environments to produce viable offspring.

A

Species

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2
Q

A species role and position in its environment; a species’ interactions with the biotic and abiotic factors of its environment

A

Niche

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3
Q

Within a species; between individuals of the same species

A

Intraspecific

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4
Q

Between different species

A

Interspecific

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5
Q

One species is completely dependent on the other, which is usually harmed

A

Parasitism

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6
Q

One organism captures, kills and feeds on another

A

Predation

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7
Q

Necessary and positive association between two organisms

A

Mutualism

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8
Q

A type of sampling in which a sample is taken of each strata of the population

A

Stratified sampling

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9
Q

Uses 100 point grid to estimate abundance of a particular species (eg quadrats)

A

Percentage Cover

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10
Q

The probability that a species will be found within a single quadrat
No of quadrats in which the species is found/total no of quadrats

A

Percentage Frequency

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11
Q

A measure of the number of species compared to the no. of individuals found in a sample, doesn’t say anything about evenness

S = s √N

A

Species Richness

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12
Q

How close in numbers each species in an environment is

A

Evenness (Relative Species Abundance)

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13
Q

A measure of the number of species found in a sample compared with the number of individuals

A

Species Diversity (Simpsons Diversity Index)

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14
Q

Increase in the size of a population in a particular habitat over time

A

Population growth

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15
Q

The graphical representation of the change in population density of an organism as it increases rapidly and then stops suddenly, due to environmental or other factors

A

J-Shaped Population Curve

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16
Q

The graphical representation of the change in population density of an organism when it initially increases slowly and then rapidly as it approaches an exponential growth rate, but then decreased and levels off as the environmental carrying capacity is reached

A

S-Shaped Population Curve

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17
Q

Organism that eats another living organism (or part of an organism) for nutrition

A

Consumer

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18
Q

Convert simple inorganic chemicals to complex organic molecules

A

Producer

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19
Q

Amount of organic matter in a system

A

Biomass

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20
Q

The total amount of organic matter in an ecosystem produced as a result of photosynthesis

A

Gross Primary Production (GPP)

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21
Q

Amount of energy available for herbivores in an ecosystem

A

Net Primary Production

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22
Q

The role and space an organism fills in an ecosystem, including all its interactions with the biotic and abiotic factors of its environment

A

Niche (Ecological Niche)

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23
Q

The ‘potential’ job of a species resulting from its adaptations/competition with other species

A

Fundamental Nice

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24
Q

The actual job of a species resulting from its adaptations/competition with other species

A

Realised Niche

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25
Change and development in plant communities over time to a climax community (hundreds of years).
Primary Succession
26
Second colonisation event occurring when previous plant community has been destroyed.
Secondary Succession
27
A double stranded molecule that occurs bound to proteins (histones) in chromosomes in the nucleus, as unbound circular DNA in the cytosol of prokaryotes and in the mitochondria and chloroplasts of eukaryotic cells.
DNA (Deoxyribonucleic Acid)
28
Protective structures found at the end of chromosomes.
Telomeres
29
Basic unit of DNA, consist of a sugar, phosphate and base.
Nucleotide
30
Enzyme that separates the two strands of parent DNA
DNA Helicase
31
Symbol 2n, somatic cells
Diploid Cells
32
Gametes, contain half the number of chromosomes, symbol ‘n’.
Haploid Cells
33
The process in which gametes are produced.
Meiosis
34
The failure of homologous chromosomes to separate during meiosis.
Non-disjunction
35
The presence of an abnormal number of chromosomes in a cell.
Aneuploidy
36
Refers to a single characteristic controlled by two or more genes.
Polygenic Inheritance
37
Same allele combo (YY or yy)
Homozygous
38
Different alleles (Yy)
Heterozygous
39
Used widely in molecular biology to quickly make copies of a specific DNA segment
Polymerase Chain Reaction (PCR)
40
Separation of DNA molecules according to size using an electrical field.
Gel Electrophoresis
41
Required to form recombinant DNA
Vector
42
Circular DNA structure
Plasmid
43
A group of organisms that can potentially interbreed in nature to produce viable, fertile offspring.
Species
44
Different groups radiating from a common ancestor.
Divergent Evolution
45
When organisms occupy similar environments and come to resemble one another (distantly related)
Convergent Evolution
46
Occurs when there is a split from a common ancestor, but the separate groups evolve in a similar manner.
Parallel Evolution
47
Different groups interacting so they act as a selective force on each other.
Co-Evolution
48
An ancestral species splits into two or more descendant species that are genetically different from one another and can no longer interbreed.
Speciation
49
Speciation- geographically isolated populations
Allopatric Speciation
50
Speciation- Small population isolated at the edge of a larger population
Peripatric Speciation
51
Speciation- continuously distributed population
Parapatric Speciation
52
Speciation- Within the range of the ancestral population.
Sympatric Speciation
53
The variation of allele frequencies at or above the level of species over geological time, resulting in the divergence of taxonomic groups, in which the descendant is in a different taxonomic group to the ancestor.
Macroevolution
54
Evolution- Descendants become different in form from their common ancestor
Divergent Evolution
55
Evolution- Independent evolution of similar traits in species that once shared a common ancestor
Parallel Evolution
56
Evolution- Independent development of similarities between species as a result of selection pressures and ecological roles.
Convergent Evolution
57
Evolution: Two or more species reciprocally affect each other’s evolution.
Co-Evolution
58
Small scale variation of allele frequencies within a species or population, in which the descendant is one of the same taxonomic group as the ancestor.
Microevolution
59
Change in the genetic composition of a population during successive generations, which may result in the development of a new species
Evolution
60
The widespread and rapid extinction of a large number of species due to a catastrophic global event or rapid widespread environmental change.
Periodic Mass Extinctions
61
The diversification of a species
Evolutionary Radiation
62
An evolutionary process in which organisms diversify rapidly from an ancestral species into several divergent forms.
Adaptive Radiation
63
The history of the evolution of a species or group, especially in reference to lines of descent.
Phylogyny
64
Selection- Occurs when natural selection for a particular phenotype maintains the consistency of a population.
Stabilising Selection
65
Selection- Occurs when natural selection favours once in a typical extreme.
Directional Selection
66
Selection- Occurs when natural selection favours individuals with extreme phenotypes.
Disruptive Selection
67
Occurs when there are changes in small populations gene pool due to chance.
Genetic Drift
68
A cause of genetic drift resulting from a small subgroup of the ‘parent’ population colonising a new area.
Founder Effects
69
Occur when an event drastically reduces the size of a population and therefore its genetic diversity.
Bottleneck
70
The movement and exchange of alleles between populations of a species.
Gene Flow

Biology Definitions Unit 3 and 4 (3 decks)

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