Biodiversity and Taxonomy

Question 1

two organisms belong to the same species if they are able to produce _____________ offspring.

Answer 1

fertile

Question 2

define species

Answer 2

A group of similar organisms that are able to breed to produce fertile offspring

Question 3

Examples of courtship behaviour

Answer 3

Bright colours and/or patterns;
Songs;
Smells / pheromones;
Dances / movement;
Gift-giving;

Question 4

Give two ways in which courtship increases the probability of successful mating (2).

Answer 4

1. Attracts/recognises same species;
2. Attracts/recognises mate/opposite sex;
3. Indication of sexual maturity / fertility / synchronises mating;
4. Stimulates release of gametes;
5. Form pair bond;

Question 5

A [1] classification system attempts to arrange species into groups based on their [2] origins and relationships.

It uses a hierarchy in which smaller groups are placed within larger groups, with no [3] between groups

Answer 5

[1] phylogenetic
[2] evolutionary
[3] overlap

Question 6

Define taxon

Answer 6

Each group in the heirarchy

e.g., Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

Question 7

List the taxons by number of organisms in each group - from largest to smallest group.

Answer 7

(Largest) Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species (Smallest)

Question 8

(AO1)

List the taxons from most related to least related group

Answer 8

(Most related) Species, Genus, Family, Order, Class, Phylum, Kingdom, Domain (Least related)

Question 9

Hummingbirds belong to the order Apodiformes. One genus in this order is Topaza.

Name one other taxonomic group to which all members of the Apodiformes belong.

Answer 9

Kingdom / phylum / class

Question 10

Name of sytem used to universally identify each species with a genus and species

Answer 10

Binomial system

Question 11

describe how organisms are grouped in a phylogenetic classification system (2).

Answer 11

1. Hierarchy of groups with no overlaps

OR smaller groups within larger groups with no overlaps;

2. Grouped according to evolutionary relationships / ‘common ancestry’

Question 12

The more closely related two species, the more [1] their shared [2] ancestor.

Answer 12

[1] recent
[2] common

Question 13

Genetic diversity within, or between species, can be made by comparing…..

Answer 13

Frequency of measurable or observable characteristics
Base sequence of DNA
Base sequence of mRNA
Amino acid sequence of proteins

Question 14

The genetic diversity of species is measured by comparing differences in the base sequence of DNA or differences in the base sequence of mRNA.

Give two other ways in which genetic diversity between species is measured.

Answer 14

Comparing measurable or observable characteristics;

Comparing amino acid sequences/primary structures (of a/named/the same protein);

Question 15

The more similar the DNA base sequence of two species, the more [1] related they are and the more [2] their shared common ancestor.

Answer 15

[1] closely
[2] recent

Question 16

in classification, comparing the base sequence of a gene provides more information than comparing the amino acid sequence for which the gene codes. Explain why (3).

Answer 16

1) DNA base sequence is longer than amino acid sequence;

2) Genes contain introns;

3) Same amino acid may be coded for by more than one codon / degenerate code;

Question 17

Genetic diversity in soil species was traditionally inferred by making observations after growing prokaryotes on agar plates.

However, it is estimated that less than 10% of prokaryotes found in soil will grow if spread on an agar plate in a laboratory.

In recent years, our knowledge of prokaryotic biodiversity in the soil has increased.

Suggest why (2).

Answer 17

1. DNA/genome sequencing now used;
2. Now can analyse/identify more prokaryote species (in the community);
3. Rather than just recording measurable / observable characteristics;

Question 18

Littorina littorea is a species of snail found on rocky sea shores.

A student investigated variation in snail shell height in two populations of snails.

Give two ways in which the student could ensure his samples would provide a reliable measure of the variation between individuals in each population.

Answer 18

1. Select at random;
2. Large sample / number of snails (more than 10);

Question 19

Why should sampling be random?

Answer 19

To reduce bias

This also make the results / experiment more reliable

Question 20

why should a sample be large?

Answer 20

To ensure it is representative;

To calculate a mean so results are more reliable;

Identify anomolus results;

Question 21

the student noticed there was a difference in shell height between these populations of snails. He wanted to investigate if the difference was significant.

Give a suitable null hypothesis to use in his investigation and name the statistical test to use with these data.

Answer 21

1. No significant difference between mean height (in these populations);
2. T-test;

Question 22

The student could determine the median, mode and range from his measurement of shell heights in two populations of snails.

Give two other statistical values the student could calculate from his measurement of shell heights in these populations.

Answer 22

Mean and standard deviation

Question 23

Haemoglobins are chemically similar molecules found in many different species.

Differences in the primary structure of haemoglobin molecules can provide evidence of phylogenetic (evolutionary) relationships between species.

Explain how (5).

Answer 23

1. Random mutations change DNA base sequence;
2. Causing change in amino acid sequence;
3. Mutations build up over time;
4. More mutations / more differences (DNA base sequence / amino acid sequence / primary structure) between distantly related species;

OR accept converse

5. Distantly related species have earlier common ancestor;

OR Closely related species have recent common ancestor;

Question 24

Biodiversity can be measured in a wide a range of habitats, from a small local habitats to the entire ____________.

Answer 24

earth

Question 25

Two ways of measuring biodiversity

Answer 25

Species richness Index of biodiversity

Question 26

Define species richness

Answer 26

Number of different species in a community

Question 27

Define community

Answer 27

All the populations of the different species living together in the same area (habitat or ecosystem) at the same time.

Question 28

Define index of biodiversity

Answer 28

The relationship between the number of species in a community and the number of individuals in each species.

Question 29

What is the below equation for? \(d=\frac{N(N-1)}{\sum (n)(n-1)}\)

Answer 29

calculates the index of biodiversity

Question 30

What does the ‘N’ represent?

Answer 30

Total number of individuals from all species

Question 31

What does the ‘n’ represent?

Answer 31

Number of individuals for each species

Question 32

The greater the index of biodiversity, the more _____________ in the habitat.

Answer 32

biodiversity

Question 33

Explain why it is more useful to calculate an index of diversity than to record species richness (2).

Answer 33

1. Index of diversity also measures number / population size of each species; 2. So useful because may be many of some species OR may be few of other species;

Question 34

It was important that the sampling procedure was standardised when collecting the Slate Drake mayflies from the two sites. Give one way in which the sampling procedure could be standardised.

Answer 34

same size of area (sampled) OR Same size net/mesh OR Same sampling time OR Samples taken at same time of day/on same day;

Question 35

the UK government pays farmers to leave grassy strips around the edges of fields of crops. These grassy strips contain a variety of plant species. Leaving the strips is an attempt to encourage biodiversity of animals. Give two reasons why the grassy strips increase the biodiversity of animals.

Answer 35

1. Increase in plant diversity leads to more types of food for animals; 2. Increase in variety of animals leads to increase in predator species; 3. Increase in habitats

Question 36

Deforestation often involves clearing large areas of forest for use as agricultural land. Deforestation reduces the diversity index of an area cleared in this way. Explain why (2)

Answer 36

1. Fewer habitats 2. Reduced food sources 3. Reduces total number of species (N) 4. Reduces numbers of each species (n)

Question 37

uggest two reasons for conserving rainforests

Answer 37

1. Conserve / protect / species / plants / animals / organisms OR for biodiversity; 2. Conserve/protect habitats/niches OR provides/many habitats/niches; 3. Reduces climate change; 4. Source of medicines/drugs/wood; 5. Reduces erosion/eutrophication; 6. For tourism;

Question 38

suggest how a student would obtain data to give a more accurate value for the index of diversity for a habitat.

Answer 38

1. Take more samples and find mean; 2. Method for randomised sampling e.g. using a random number generator to generate coordinates;

Question 39

Species richness and an index of diversity can be used to measure biodiversity within a community. What is the difference between these two measures of biodiversity?

Answer 39

Species richness measures only number of different species OR species richness does not measure number of individuals.