What is the term for the variation in DNA between individuals within a species or between different species?
Genetic diversity
Genetic diversity can exist within a species or between species and arises from differences in DNA sequences.
What specific part of DNA is compared when scientists directly examine genetic differences between organisms?
Base sequence
Differences in the order of nucleotide bases reveal genetic variation.
When comparing organisms, what RNA feature can be analysed to investigate genetic differences?
Base sequence of mRNA
mRNA sequence reflects the DNA sequence of expressed genes.
Differences in what part of proteins can be compared to investigate relationships between organisms?
Amino acid sequence
The order of amino acids in proteins is determined by DNA and mRNA sequences.
True or False:
Comparing amino acid sequences of proteins can help scientists infer evolutionary relationships between organisms.
True
More similar amino acid sequences usually indicate closer evolutionary relationships.
When investigating variation within a population, what sampling method ensures every individual has an equal chance of being selected?
Random sampling
Reduces bias and increases reliability of collected data.
Fill in the blank:
Quantitative investigations of variation often involve calculating the ______ value of collected data to represent the average.
mean
The mean provides a measure of the central tendency of the data.
What statistical measure describes how spread out values are around the mean in a dataset?
Standard deviation
Indicates the extent of variation within the data.
True or False:
Students are required to calculate standard deviation in written AQA Biology exam papers.
False
Students may interpret standard deviation values but are not required to calculate them in exams.
When comparing organisms genetically, what type of biological relationship can similarities in DNA sequences help suggest?
Evolutionary relationships
Closely related organisms tend to have more similar DNA sequences.
True or False:
Modern gene technology allows scientists to investigate genetic diversity by directly analysing DNA sequences.
True
Advances in molecular techniques allow direct comparison of DNA rather than relying only on observable traits.
Fill in the blank:
Before modern molecular techniques, scientists often inferred genetic differences by comparing ______ characteristics.
observable
Examples include physical traits or measurable phenotypic differences.
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1: Biological Molecules138
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1: Enzymes & Digestion16
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1: Cells & Ultrastructure52
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1: Transport Across Membranes20
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1: Cell Division20
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2: Exchange & Transport Systems76
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2: Plant Transport20
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2: Immune System36
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3: DNA & Protein Synthesis27
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3: Genetic Diversity14
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3: Biodiversity & Classification32
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3: Investigating Diversity12
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4: Natural Selection & Evolution42
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4: Populations & Ecosystems24
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4: Energy Transfer in Ecosystems35
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5: Photosynthesis23
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5: Respiration17
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5: ATP & Energy Transfer11
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6: Homeostasis57
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6: Nervous Coordination53
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6: Stimuli & Response62
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6: Muscles14
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7: Inheritance12
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7: Populations (Hardy–Weinberg)15
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8: Gene Mutations & Expression58
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8: Gene Technologies & Genomics46
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8: Disease24
