3.4.7 Investigating biodiversity Flashcards
What are the advantages and disadvantages of using DNA and mRNA to establish DNA diversity?
+ve
DNA - No transcriptional errors
mRNA - more easily accessible - cytoplasm, rER
-ve
DNA - less accessible - in nucleus
mRNA - transcriptional errors and lack of introns (after splicing) - less accurate
How are base sequence of DNA and mRNA used to establish DNA diversity?
The more base difference between individuals, the more distantly related the individuals are
Why and how are amino acid sequences used to establish DNA diversity
Amino acid sequence is coded by DNA and mRNA sequences
By comparing amino acid sequences of the same protein in different species, the degree of similarity determines how closely related the species are
What are the disadvantages of using amino acid sequences to establish DNA diversity?
Transcriptional errors and degenerate nature of genetic code are not accounted for
How is DNA hybridisation used to establish DNA diversity?
A single stranded DNA from 2 different species is mixed and hybridised strands may form when DNA of each species combines
The degree of similarity between the two species can be determined by the ease of which the hybrid strands are separated (using heat) as hydrogen bonds would’ve formed between complementary base pairing
The more bonds - the more similar - the harder it is to break the hybridised strand (need higher temperature)
What are the two types of variation?
Interspecific (between species)
Intraspecific (within species)
What are quantitative data?
Data that are collected by counting or measuring features within a community
Samples are collected instead of counting all organisms
What does a sampling need to be in order to be reliable?
Representative - reflect what is activating occurring in the population
Free from bias - random or systematic
Large - to identity and account for anomalies
