Variation and Diversity

Question 1

What does phylogeny mean?

Answer 1

evolutionary history between groups of organisms

Question 2

what is taxonomy

Answer 2

• the science of classification

Question 3

what is the order of taxonomy

Answer 3

domain, kingdom, phylum, class, order, family, genus, species

Question 4

what is meant by the term hierarchy

Answer 4

smaller groups placed within larger groups with no overlap between the groups

Question 5

how to define a species

Answer 5

two organisms able to breed to produce fertile offspring

Question 6

how is a species named

Answer 6

binomial (two terms)

first term = genus

second term = species

Question 7

what is courtship behaviour

Answer 7

behaviour carried out by organisms to attract a mate of the right species

Question 8

why is courtship behaviour necessary (5)

Answer 8

• allows recognition of species
• indication of sexual maturity
• recognition of opposite sex
• establishes a pair bond to raise young
• synchronised mating

Question 9

how can genetic diversity be investigated?

Answer 9

• the frequency of measurable or observable characteristics
• the amino acid sequence of the proteins encoded by DNA and mRNA
• the base sequence of DNA
• the base sequence of mRNA

Question 10

what is intraspecific variation?

Answer 10

the variation between organisms of the same species

(same species possesses the same genes but not necessarily the same alleles)

Question 11

what is interspecific variation?

Answer 11

the variation between organisms of different species

Question 12

how would you avoid/prevent sampling bias + describe a method ?

Answer 12

Random sampling

• divide study area into a grid of numbered lines
• use random numbers to obtain a series of coordinates
• take samples at the intersection of each pair of coordinates

Question 13

why is sample size important?

Answer 13

if the sample size is small , the results may not be representative of the population

Question 14

what are the benefits of using a large sample size

Answer 14

• there is a smaller probability that chance will influence the results
• statistical tests are able to be carried out to analyse the data collected

Question 15

how would you use variation in the DNA/mRNA or amino acid sequence of organisms to investigate relation/genetic diversity?

Answer 15

• the more similar the DNA, mRNA or amino acid sequence is between two organisms, the closer related they are to each other
• this is because there has been less time for mutations to occur and build up if they come from a recent common ancestor

Question 16

why is comparing DNA sequences preferred to comparing Amino Acid sequences?

Answer 16

• the degeneracy of the genetic code means the same amino acid can be coded by different base triplets
• eukaryotic DNA contains introns that can also be compared

Question 17

why is comparing mRNA base sequences sometimes preferred to comparing DNA base sequences ?

Answer 17

it is sometimes easier to isolate the mRNA from cells than DNA

Question 18

why is it more useful to calculate a species diversity index rather than recording species richness

Answer 18

the diversity index takes into account the population (number of individuals) of each species whereas species richness only counts the number of different species

Question 18

what does Biodiversity mean?

Answer 18

a term used to describe the number and variety of living organisms in a particular area

Question 19

what does Species Richness mean?

Answer 19

the number of different species in a community

Question 20

what is the Index of Diversity?

Answer 20

the number of different species and the number of individuals of each species within an area

Question 21

what causes the reduction of biodiversity?

Answer 21

Deforestation and farming practices lead to:

• decrease in variety of plant species
• decrease in the number and variety of habitats
• decrease in the variety of food sources
• decrease in animal diversity due to the factors above