7. h2 evolution questions

Anglo-Chinese Junior College Revision Package H2 Diversity & Evolution

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1 The diagram below shows the frequency and distribution of four Littorina species on a rocky shore. All feed in a snail-like manner by grazing on algae.

Which one of the following factors could not directly contribute to this distribution pattern?

A Variation in the tolerance of each species to desiccation

B Competition between species for different feeding niches

C The photoperiod and seasonal change in day length

D The differential selection of Littorina by predators

2 A comparison was made between human, rabbit, mouse and chimpanzee of the

DNA coding sequence of the globin gene DNA sequence in the introns of the globin gene Amino acid sequence of the globin polypeptide

It is possible to conclude from this data that

A a human is more closely related to a mouse than to a rabbit.

B the variation between chimpanzees and human occurs in a region of the globin gene which would code for amino acids.

C the variation in the intron sequence between human and mouse would account for some of the differences in the amino acid sequence.

D the comparison between human and chimpanzee indicates that human is more closely related to chimpanzee than to rabbit and mouse.


2

3 The chart shows the classification of two species of crocodiles.

To which class do these crocodiles belong to?

A Chordata

B Crocodylidae

C Loricata

D Reptilia

4 The graph shows the effect of pesticide treatment on beetles in Tanzania over a number of years. A standard amount of pesticide was used each year in summer.

0

20

40

60

80

100

120

2 4 6 8 10 12 14 16 18 20

time / years

% s

urv

iva

l

How is the effect of pesticide best explained?

A A few resistant beetles reproduced more successfully and the resistance allele increased in frequency.

B At every generation, an increasing proportion of beetles mutated to become resistant.

C Repeated exposure to the pesticide caused the beetles to become more resistant.

D The allele for resistance mutated from the recessive form to the dominant form.


3

5 Which of the following pairs is least likely to represent homology?

A the haemoglobin of a baboon and that of a gorilla

B the mitochondria of a plant and those of an animal

C the wings of a bird and those of an insect

D the wings of a bat and the arms of a human

6 During a storm, two male and two female seagulls are blown 300 miles to an isolated island uninhabited by seagulls (Survivor Island). They reproduce and form a new population. They cannot disperse back to the original habitat, nor can any new seagulls cross to the new island. By chance, all four original colonists were white-coloured gulls. Which option below best describes this scenario?

A Allopatric speciation

B Founder effect

C Mutation

D Stabilising selection

7 In 1954, copper waste in the Finniss River killed numerous fish. This caused various species in the area to die out. However, one species, the black-banded rainbow fish, increased in numbers. The black-banded rainbow fish have modified gills that enable the fish to filter and remove the copper before it enters their bodies. With respect to the black-banded rainbow fish, it is reasonable to conclude that

A a mutation occurred in their population in 1954.

B the ability of their gills to remove copper already existed in 1954.

C the high levels of copper in the water changed the structure of their modified gills.

D their genomes are identical with those of the other species of fish that existed in 1954.

8 Given a population that contains genetic variation, which of the following sequences

illustrate the action of natural selection?

1. Differential reproduction occurs. 2. A new selective pressure occurs. 3. Allele frequencies within the population changes. 4. Environmental change occurs.

A 2, 4, 1, 3

B 2, 4, 3, 1

C 4, 1, 2, 3

D 4, 2, 1, 3


4

9 The four graphs represent simulations of genetic drift occurring in fruit fly populations of two different sizes, 40 and 400.

Which of the following about genetic drift can be deduced from the graphs?

A It leads to non-random fixation of alleles in the population.

B There is loss of heterozygosity in the population regardless of population size.

C It is a more powerful force of evolution in small populations.

D Given sufficient time, genetic drift can produce drastic changes in allele frequencies in large populations.

10 In which of the following scenarios would allopatric speciation occur most quickly?

A A population of cheetahs undergoing little or no evolutionary change

B A population of fishes undergoing directional selection due to the introduction of a new predator

C A population of giraffes free to roam the entire nature reserve after the artificial removal of all predators

D A population of snails separated by a new fast-flowing river


5

11 Comparisons of the amino acid sequences of the -globin polypeptide have been made between humans and a number of other vertebrates. The number of differences is shown in the table below.

Organism shark kangaroo carp cow newt

Amino acid differences in -globin compared to human

79 27 68 17 62

An evolutionary relationship between these vertebrates was determined and illustrated in the figure below.

Based on the information provided, the correct placement of each animal on the figure to show the evolutionary relationship is

A V = cow, W = kangaroo, X = newt, Y = carp, Z = shark

B V = shark, W = carp, X = newt, Y = kangaroo, Z = cow

C V = carp, W = shark, X = kangaroo, Y = newt, Z = cow

D V = kangaroo, W = cow, X = newt, Y = shark, Z = carp

12 Which of the following is an example of convergent evolution?

A Hummingbird bill sizes changing in shape to fit easily into flowers.

B Competition among finches of Galapagos Islands causing speciation.

C Anteaters in Africa and South America developing long, narrow skulls.

D Maples moving northward after glaciers started to recede in North America.


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13 A researcher compared the nucleotide sequences of a homologous gene from five different species of mammals with the homologous human gene. The sequence homology between each species version of the gene and the human gene is presented as a percentage of similarity.

Species Percentage

Chimpanzee Orangutan Baboon Rhesus Monkey Rabbit

99.7 98.6 97.2 96.9 93.7

What valid conclusion can be drawn from these data?

A Humans and other primates evolved from rabbits within the past 10 million years.

B Humans are most related to the Rhesus Monkey because of their blood type.

C Among the organisms listed, humans shared a common ancestor most recently with chimpanzees.

D Humans evolved from chimpanzees somewhere in Africa within the last 6 million years.

14 An interbreeding population of finches became separated geographically, forming two

isolated groups. Each group then became subjected to different selection pressures. One group was then introduced into the habitat of the other. Which one of the following would determine whether they now formed two distinct species?

A They had been separated for more than three million years.

B They showed marked differences in the shape of their beaks.

C Several genes now possessed different base sequences.

D They failed to produce fertile F1 hybrids.

15 In haemoglobin, the amino acid sequence of the beta polypeptide chains differs among

species which possess the molecule. The beta chains of the species shown in the table below were analysed. The number of amino acid differences between Man and each of the species was counted and ranged between 8 and 127.

Which one of the following shows the differences which would be consistent with the proposed evolutionary relationships between the organisms?

Amino acid differences

dog earthworm frog lamprey

rhesus monkey

A 8 67 15 127 125

B 15 127 67 125 8

C 67 15 127 8 67

D 125 8 67 15 127


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16 The 200th anniversary of the birth of Charles Darwin was celebrated in 2009.

In the development of his ideas on evolution, Darwin proposed that

A all members of a species have an equal chance of survival.

B offspring look more like their parents than they do to unrelated people.

C individuals in a population have the same chance for reproductive success.

D environmental changes that change the structure of individuals are transmitted to the next generation.

17 Members of two different species possess a similar-looking structure that they use in a similar fashion to perform the same function. Which information would best help distinguish between an explanation based on homology versus one based on convergent evolution?

A The two species live at great distance from each other.

B The two species share many proteins in common, and the nucleotide sequences that code for these proteins are almost identical

C The sizes of the structures in adult members of both species are similar in size

D Both species are well adapted to their particular environments.

18 The graph shows the change in the number of bacterial samples from some New York

hospitals that were resistant to the antibiotic vancomycin in 1992 1994. 40 samples were taken each month from randomly selected patients who had become infected with bacteria in hospital.

Which of the following most accurately describes the cause of the changes in the frequency of the vancomycin resistant phenotype that occurred?

A Effect of artificial selection B Effect of natural selection C Purely due to genetic drift D Purely due to random sampling effects


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19 The table below shows the amino acid sequence of part of the beta-haemoglobin molecule found in 6 different vertebrates. The beta-globin chain has a total of 146 amino acids. Only the amino acids found in positions 101 to 116 are represented.

Using the information above, a suitable phylogenetic diagram would be


9

20 What does the neutral theory of molecular evolution says about many mutations?

A They are not affected by mutagens.

B They are not influenced by natural selection.

C They occur in non-coding parts of the genome.

D They only affect diploid organisms.

21 What is one similarity and one difference between classification and phylogeny?

A Both organise organisms into groups based on their characteristics but phylogeny takes into consideration the evolutionary relationships between groups.

B Both put organisms in hierarchical groups but classification does not show a branching pattern of evolutionary relationships.

C Both rely on physical characteristics of organisms but phylogeny does not require scientific names.

D Both take into account the common ancestors of organisms but classification is hierarchical in nature.

22 Which pattern of mutation rate would be most helpful if one desires to use a gene as a molecular clock to determine evolutionary relatedness among species?

Rate

of mutation

Time


10

23 Molecular homology of myoglobin is used to determine evolutionary relatedness in a range of

mammals. Either nucleic acids or proteins can be sequenced. The sequence of nucleic acids and proteins are compared. Which sequence will vary least in related mammals?

A amino acid

B DNA

C edited mRNA transcript

D primary mRNA transcript

24 Why is that some antibiotics, such as penicillin, are no longer effective in the treatment of certain diseases caused by bacteria?

A The antibiotic causes bacteria to mutate into resistant forms.

B Human populations have developed antibodies which render the antibiotic ineffective.

C Continued use of the antibiotic has gradually increased the resistance of human populations to bacterial infection.

D Some bacteria possess inheritable resistance to the antibiotic.


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Question 1 (a) (i) Outline what is meant by stabilising selection. [1]

(ii) State one condition under which stabilising selection takes place.. [1]

Some European clover plants can produce cyanide. Those plants that can produce cyanide are called cyanogenic while those that cannot are called acyanogenic. Cyanide is toxic to the cells of animals and plants. Fig. 1.1 shows how the production of cyanide in a species of European clover is genetically controlled.

Fig. 1.1 (b) With reference to Fig. 1.1, explain how the production of cyanide depends on the genotypes

of the clover plants. [3]

When the leaves of cyanogenic plants are damaged by slugs or exposed to low temperatures, cell membranes are disrupted. This causes the release of the enzymes that control the reactions which produce cyanide. Slugs are not usually active at temperatures below 0oC. (c) Suggest how the cell membranes will be damaged by low temperature. [2]

Dominant

allele of gene 1

Dominant

allele of gene 2

Enzyme 1 Enzyme 2

Substance 1 Substance 2 Cyanide

released


12

The proportions of cyanogenic and acyanogenic plants in clover populations were determined in different parts of Europe. These are shown in Fig. 1.2, together with the mean minimum winter temperatures. Fig. 1.2 also illustrates isotherms, lines joining places with the same mean January temperature.

Fig. 1.2

(d) With reference to Fig. 1.2, explain how the different proportions of cyanogenic plants may

have evolved in populations found in different parts of Europe. [3]

[Total: 10]


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Question 2 The mitochondrial DNA (mtDNA) of a red alga, Porphyra purpurea, a circular genome of 36,753 kbp, has been completely sequenced and a total of 57 densely packed genes have been identified. Comparisons were made with mtDNAs from animals, fungi, protists and plants, and there is strong evidence that red algae (rhodophytes) share a common ancestry with green algae (chlorophytes) and plants. Fig. 2.1 shows a phylogenetic tree constructed from these studies.

Fig. 2.1

(a) With reference to Fig. 2.1, comment on the relationship between green and red alga as

compared to land plants. [1]

(b) Explain the significance of the branching points in the phylogenetic tree. [1]


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(c) Suggest two reasons why mtDNA is useful in examining the evolutionary relationships between the different species in Fig. 2.1. [2]

The table below shows the number of nucleotide differences in the mtDNA of various vertebrates.

(d) Label on the phylogenetic tree in Fig. 2.1, the following vertebrates: Human, Elephant, Platypus, Ostrich and Crocodile. [2] (e) Explain how the fossil record can be used to support evolution. [3]


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(f) Anteaters and echidnas are two distantly related animals with striking similarities such as pointy snout, sharp curved claws and a diet of feeding on ants.

However anteaters are often confused with echidnas due to the similarity in their appearance. Explain the term biogeography and how the resemblance could have arisen despite the two types of mammals being found in different geographical regions. [3]

[Total: 12]


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Question 3 Sickle-cell anaemia is a genetic blood disorder characterized by red blood cells that assume an abnormal, rigid, sickle shape. Life expectancy is shortened, with studies reporting an average life expectancy of 42 in males and 48 in females. The gene defect is a known mutation of a single nucleotide, which results in glutamate being substituted by valine at position 6. The genetic disorder is due to the mutation of a single nucleotide, from a GAG to GTG codon mutation. In conditions of normal oxygen concentration, the mutation causes no apparent effects on the secondary, tertiary, or quaternary structure of haemoglobin. However, under conditions of low oxygen concentration, the deoxygenated form of haemoglobin exposes a hydrophobic patch on the protein, which the hydrophobic residues of the valine at position 6 of the beta chain in the sickle-cell haemoglobin are able to associate with, causing molecules of haemoglobin S molecules to aggregate and form fibrous precipitates. (a) Explain the meaning of selection pressure. [1]

(b) Compare the relative biological fitness of an individual which is homozygous for the HbS allele and an individual which is homozygous dominant for HbA. [1]

In areas where malaria is common, those with only one of the two alleles of the sickle-cell haemoglobin are more resistant to malaria, since the infestation of the malaria parasite is halted by the sickling of the cells which it infests. When within the erythrocyte, the parasite produces a group of enzymes known as plasmepsins, which are aspartic proteases used to degrade haemoglobin. Some of the amino acids produced by the hydrolysis are then utilized in the synthesis of parasite protein. (c) Suggest why the parasitic infection of the red blood cells is less effective in individuals who carry a single copy of the HbS allele. [2]


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(d) In areas where malaria is common, explain the expected changes in frequency of the HbS allele in a populations gene pool over successive generations as a result of natural selection. [3]

In an investigation designed to assess the possibility of using RFLPs to screen for sickle cell anaemia, it was determined that the HbS allele was frequently associated with a 13kb restriction fragment, associated with the loss of a hpaI restriction site adjacent to the haemoglobin gene locus, caused by the insertion of several nucleotides within the restriction site. The insertion mutation in the hpaI restriction site is known to be selectively neutral. The neutral theory of evolution proposes that changes in the frequency of most selectively neutral alleles in a populations gene pool are caused by the process of genetic drift. (e) Explain the meaning of the phrase selectively neutral. [1]

(f) Briefly describe the process of genetic drift. [2]

(g) Explain whether the high frequency of individuals with the HbS allele in regions of where malaria is common is caused by genetic drift. [2]

[Total: 12]


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Question 4 (a) State what is meant by the term gene mutation. [2]

(b) Explain why some gene mutations do not result in a change in amino acid. [3]

Fig. 4.1 shows a family tree constructed based on differences between the alpha haemoglobins of different species.

Fig. 4.1

(c) Explain what direct evidence exists for the time scale in Fig.4.1. [2]

The gene for alpha haemoglobin is carried on chromosome 16 and contains three coding sections and two non-coding sections. (d) State the name given to the

(i) coding sections

(ii) non-coding sections [1]


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Also on chromosome 16, there exist duplicated but non-functional pseudogenes, that resemble the functional gene but have some defect that renders them useless. The rate of gene mutation in non-coding sections of genes and pseudogenes is very much faster than in the coding sections of genes. (e) Suggest why the apparent rate of accumulation of gene mutations in coding sections is

slower. [2]

[Total: 10]


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Question 5 The fruit fly, Drosophila, has many different species. Three of these species, Drosophila pseudoobscura, D. persimilis and D. miranda, are thought to be closely related. Samples of these three species were collected from the western United States of America. Fig. 5.1 shows where these species naturally occur.

Fig. 5.1

The base sequences of four regions of DNA of each species were sequenced. The divergence of these base sequences in D. pseudoobscura and D. persimilis from the sequences in D. miranda was calculated. The results are shown in Table 5.1.

Table 5.1


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(a) With reference to Table 5.1, describe the evidence that D. miranda may be more closely related to D. persimilis than to D. pseudoobscura. [2]

(b) Suggest why there is more divergence in some regions of DNA than in others. [2]

(c) The area where D. pseudoobscura is found is separated from the areas where the other

two species are found by a high range of mountains.

Explain how the species D. pseudoobscura could have evolved from a population of D. miranda. [4]

[Total: 8]


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Question 6 Fig. 6.1 shows the degree of copper tolerance in bent grass (Agrostis tenuis) growing on old abandoned mine sites in Great Britain. Although mining has ceased in these areas, there is still a greater concentration of heavy metal ions in the soil as compared to other areas. Heavy metals are generally toxic to plants but alleles of certain genes confer resistance.

Fig. 6.1

(a) State the reason for the bent grass populations showing a continuous range of copper

tolerance rather than two distinct groups of tolerant and non-tolerant plants. [1]

(b) Outline briefly how one of the alleles for copper tolerance first arose and how variation in

the degree of copper tolerance within the population could have come about. [2]

(c) Explain how natural selection has resulted in the high level of copper tolerance of plants at

the mine site. [2]

Bent Grass

(Agrostis tenuis)


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(d) Grasses with the copper tolerant alleles have a lower growth rate on normal soil than other grasses without these alleles. However, grasses still have some level of copper tolerance even 60-100m away from the mine site.

State the factor other than natural selection that is most likely to contribute to the copper tolerance-allele frequency in non-mine sites surrounding this mine site. [1]

(e) Another type of grass was also observed to grow in areas with heavy-metal contamination.

(i) As a result of this observation, a student studying these grasses concluded that this second type of grass must also be of the species Agrostis tenuis. State the type of species concept that was used by the student to reach his conclusion. [1]

(ii) Briefly describe one other species concept that could be used to determine if the two types of grasses are different species or not. [2]

Fig. 6.2 shows a cladogram generated from shared anatomical features of several organisms. For example, out of seven key traits, all of these animals have a dorsal nerve cord, but only humans, monkeys and kangaroos have mammary glands.

Fig. 6.2


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Table 6.1 shows the total number of differences in amino acids in cytochrome-C between humans and each of the animals.

Table 6.1

Organism No. of differences in cytochrome-C amino acid sequence (compared with human cytochrome-C)

Tuna 21

Bull-frog 18

Snapping turtle 15

Kangaroo 10

Rhesus monkey 1

(f) With reference to the data from Fig 6.2 and Table 6.1, explain the role of molecular data in reconstructing phylogenetic relationships amongst these organisms. [3]

[Total: 12]


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Question 7

In Central America the Isthmus of Panama closed about 3 million years ago creating a land bridge between North and South America. Snapping shrimps on the Caribbean side of the isthmus appear almost identical to those on the Pacific side, having once been members of the same population. When males and females from different sides of the isthmus were put together they snapped aggressively instead of courting. They had become separate species.

An outline of the region is shown in Fig. 7.1.

Fig. 7.1

(a) Complete Table 7.1 to show the classification of one of the species of snapping shrimps.

Table 7.1

kingdom

phylum Arthropoda

Malacostraca

order Decapoda

Alpheidae

genus

species Alpheus heterochaelis

[2]

(b) State the likely isolating mechanism and type of speciation taking place. [2]

Isolating mechanism

Type of speciation


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(c) Explain how the process of speciation occurred in the snapping shrimp population. [5]

(d) Variation is important for natural selection to occur. However, natural selection tends to reduce genetic variation. Suggest how genetic variation may be preserved in a natural population. [3]

[Total: 12]


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Essay 1. Discuss the sickle cell mutation and its prevalence in malaria-stricken areas of Africa. [7] 2. Describe the role of meiosis in natural selection. [10] 3. (a) Explain how mutations for antibiotic resistance spread so rapidly among bacteria. [4]

(b) Outline the role of isolating mechanisms in the evolution of new species. [6]

4. Explain how substitution of one nucleotide in coding DNA can be selected for to bring

about evolution. [6]

7. h2 evolution questions

Documents

littorina species

species of crocodiles

globin gene dna sequence

animal c

insect d

gorilla b

various species

resistant beetles