Self-Evaluation Key Area 2.1: Field Techniques for Biologists

Advanced Higher Biology

Homework Booklet

Unit 2: Organisms and Evolution

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Name: ______

Self-Evaluation Key Area 2.1: Field Techniques for Biologists

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Exercise 1: Key Area 2.1: Field Techniques for Biologists

1.The diagram below shows some phyla in the animal kingdom.

Which row in the table identifies the phyla X, Y and Z?

Phylum
X / Y / Z
A / Chordata / Nematoda / Arthropoda
B / Arthropoda / Nematoda / Chordata
C / Nematoda / Arthropoda / Chordata
D / Arthropoda / Chordata / Nematoda

2.Which of the following descriptions of animal behaviour avoids the use of anthropomorphism?

AIn some primate species, alpha males often bully lower-ranking animals.

BIn late summer, worker bees like to visit heather flowers.

CThe grin on the chimpanzee’s face showed that it was amused by the gesture.

DThe male moth is attracted to the female by the scent molecules that she emits.

3.A population of chafer beetles were damaging the tees and greens of a golf course. Results from a mark and recapture study suggested a population size that was too small to account for the extent of the damage caused.

One possible reason for this is that the

Awhite paint used to mark the beetles washed off some of them before the recapture

Bwhite paint used to mark the beetles made them more visible to predators than unmarked beetles

Ctotal number of beetles in the recaptured sample was less than the number first captured and marked

Dmarked beetles did not have enough time, after release, to spread out and mix with the rest of the population.

4.C. elegans is a model organism of the phylum

AChordata

BArthropoda

CNematoda

DMollusca.

5.The formula N = MC/R is used to estimate population size using mark and recapture data.

N = population estimate

M = number first captured, marked and released

C = total number in second capture

R = number marked in second capture

In a survey to estimate a woodlouse population, the following data were obtained:

Woodlice captured, marked and released / = 80
Marked woodlice in second capture / = 24
Unmarked woodlice in second capture / = 96

The estimated population of the woodlice was

A200

B320

C400

D3840.

6.Dicrocoelium dendriticum is a flatworm parasite of grazing vertebrates such as sheep and cattle.

Which row in the table below shows the phyla to which these species belong?

Dicrocoelium / cattle/sheep
A / Nematoda / Chordata
B / Platyhelminthes / Arthropoda
C / Nematoda / Arthropoda
D / Platyhelminthes / Chordata

7.Eggs from leopard geckos kept in breeding cages were collected and incubated at two temperatures over five breeding seasons. When each new gecko hatched, its gender was noted. The graph below shows how temperature affected gender in the population.

How many females would be present in a population of 500 leopard geckos after four seasons at 32.5oC?

A150

B200

C300

D350

8.In 1971, biologists moved five adult pairs of Italian wall lizards (Podarcis sicula) from their small home island of Kopiste to the neighbouring small island of Mrcaru, which did not have a lizard population. On their return in 2005 Mrcaru was found to have a large population of P. sicula (confirmed by genetic analysis) with significantly larger heads and a greater bite force than the lizards from Kopiste. Their digestive systems were also found to contain microorganisms that assist in the breakdown of plant cell walls.

The summer diets of the two lizard populations are shown below.

a)Describe the most significant change in the summer diet of the lizards on Mrcaru.

______

b)This study involved taking representative samples of the lizard populations on the two islands.

State one feature of a representative sample.

______

9.Fur seals spend most of their lives feeding in Antarctic seas. During the short summer they come ashore to breed.

The figure below shows the number of fur seals breeding on Signy Island from 1956 to 1986.

a)Calculate the percentage increase in the size of the breeding seal population between 1980 and 1986.

Space for calculation and working

______%

b)Permanent quadrats were established to investigate the effect of fur seals on ground cover plants. The table shows the mean percentage of cover of a number of plant species sampled in the permanent quadrats in 1965 and 1985.

Plant species / Percentage cover (%)
1965 / 1985
Drepanocladus uncinatus / 30 / 0
Bryum algens / 49 / 0
Tortula filaris / 16 / 0
Tortula saxicola / 4 / 4
Prasiola crispa / 1 / 41

i)Explain the changes in percentage cover between 1965 and 1985.

______

ii)Suggest why the percentage cover in 1985 is not 100%.

______

c)i)Describe one consideration that must be taken into account when carrying out sampling in an ecosystem.

______

ii)Describe the process of stratified sampling.

______

End of Key Area 2.1

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Self-Evaluation Key Area 2.2: Organisms

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Exercise 2: Key Area 2.2: Organisms

1.Which line in the table correctly identifies genetic drift?

Type of process / Size of population from which alleles are likely to be lost
A / random / small
B / random / large
C / non-random / small
D / non-random / large

2.In evolutionary theory, fitness can be described in absolute or relative terms.

Absolute fitness is the ratio of…

A surviving offspring of one phenotype compared with other phenotypes

B surviving offspring of one genotype compared with other genotypes

C frequencies of a particular phenotype from one generation to the next generation

D frequencies of a particular genotype from one generation to the next generation.

3.Ellis-van Creveld syndrome is a rare genetic condition. It is much more common in an isolated population in North America, which was founded by a small number of individuals, than in the general population.

The most likely explanation for this is

Anatural selection

Bsexual selection

Crandom mutation

Dgenetic drift.

4.Which of the following would be true if a population’s gene pool remained unaltered for many generations?

AMating was random

BMigration was common

CGenetic drift had occurred

DCertain alleles had a selective advantage

5.The frequency of a given allele in a population is a measure of how common that allele is as a proportion of the total number of copies of all alleles at a specific locus. For a locus with one dominant allele (A) and one recessive allele (a), the frequency of the dominant allele (p) and the frequency of the recessive allele (q) can be used to calculate the genetic variation of a population using the equations below.

p + q = 1 / p = frequency of A allele
q = frequency of a allele
p2 + 2pq + q2 = 1 / p2 = frequency of homozygous (AA) individuals
q2 = frequency of homozygous (aa) individuals
2pq = frequency of heterozygous (Aa) individuals

If the allele frequency of the recessive allele is 0·7, the proportion of individuals that would be heterozygous is

A0·09

B0·21

C0·42

D0·49

6.The error bars on the graphs represent standard errors in the mean (SEM). Which graph shows significantly different reliable data?

7.The graph below shows the fecundity (reproductive output) of the three different strains of white Leghorn domestic hens in relation to age.

Which of the following conclusions can be supported from the information shown?

AYoung hens lay more eggs during their lifetime than older hens.

BFecundity decreases faster with age in birds that lay more eggs early in life.

CThe lifelong reproductive output of all three strains is approximately equal.

DFecundity in later life is independent of fecundity in earlier years.

8.Starch consists of glucose molecules in long coiled chains, periodically joined at branching points. In the iodine test for starch, the iodine ties within the coils and the solution has a blue/black colour.

The enzyme alpha amylase (-amylase) hydrolyses starch into maltose and dextrins (short chains of glucose molecules). Samples taken from the -amylase/starch mixture, when reacted with iodine solution, will show changes in colour as hydrolysis proceeds.

Different reaction products contribute different colours, as shown below.

Within an investigation to test the effect of an inhibitor on the rate of amylase activity, researchers needed to develop a quick way to measure starch concentrations. They produced a colorimetric method based on the starch-iodine colour change. Part of the experiment to find the best wavelength is outlined below.

Amylase buffered at pH7 was incubated with different reaction mixtures at optimum temperature. After 30 minutes, hydrochloric acid was used to stop any enzyme action and then the iodine solution was added to produce the colour, Absorbance was measured across a range of wavelengths for different reaction mixtures, as shown in the graph below.

a)State the term that describes an experiment, like the one outlined, that is developing a technique within a larger investigation.

______

b)State what would be left out of the reference blank so that it functions as a control.

______

c)The researchers concluded that 580nm would be the best wavelength for quantifying amylase activity by this method.

i)Explain how they arrived at this conclusion.

______

ii)The results show that the presence of the reaction product maltose is not a confounding variable. State what is meant by the term confounding variable.

______

iii)Explain how the results show that the method will be valid in investigating the effect of amylase inhibitor on the rate of starch breakdown.

______

9.Discuss the process of evolution under the following headings:

(i)Importance of mutation in enabling evolution;(6)

(ii)Factors increasing the rate of evolution.(4)

(10)

End of Key Area 2.2

Total: ____/22

Self-Evaluation Key Area 2.3: Variation and sexual reproduction

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Exercise 3: Key Area 2. 3: Variation and sexual reproduction

1.In the fruit fly Drosophila melanogaster the gene for eye colour is sex-linked. The allele for red eye (R) is dominant to the allele for white eye (r).

A cross between two flies produced the offspring in the table below.

Sex of offspring / Number with white eyes / Number with red eyes
Female / 23 / 22
Male / 21 / 22

The genotypes of the parents in this cross were

AXrXr and XRY

BXRXr and XrY

CXRXr and XRY

DXRXR and XrY.

2.Chiasmata form when the chromosomes are arranged

Aas pairs during meiosis I

Bindividually during meiosis I

Cas pairs during meiosis II

Dindividually during meiosis II.

3.The figure below shows a nucleus in the early stages of meiosis I. Paternal chromosomes are shaded, maternal chromosomes are unshaded.

How many different gametes would be produced as a result of independent assortment?

D12

4.The diagram below gives information about conditions in four habitats.

In which habitat would parthenogenesis be most likely to occur?

5.Frequency of recombination data were used to determine the relative positions of the linked genes P, Q, R and S on a chromosome. The results are shown in the table:

Gene pair / Percentage recombination
Q and R / 14
S and Q / 4
R and S / 10
R and P / 3
P and Q / 11

The correct order of genes on the chromosome is

ARPSQ

BQSRP

CSPQR

DQPSR

6.In the insect order Hymenoptera (eg ants, bees and wasps), male individuals can be produced by parthenogenesis from an egg cell.

When parthenogenesis does occur, how many sets of chromosomes does a male wasp have in each of its body cells compared to one of his sisters?

AOne extra

BThe same number

COne fewer

DDouble the number

7.(a) The spread of a buttercup plant, Ranunculus repens, from an established flowerbed into a nearby disturbed area, is shown in the illustration below.

(i)What is meant by the term hermaphroditic as it applies to plants, such as the buttercup?

______

(ii)Explain how asexual reproduction is of advantage to the buttercup in the colonisation of this disturbed area.

______

(b)What term describes the mode of asexual reproduction in arthropods where offspring arise from unfertilised eggs?

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8.Discuss meiosis under the following headings:

(i)the sequence of events;

(ii)the origin of genetically variable gametes.

Total: ___/20

Self-Evaluation Key Area 2.4: Sex and Behaviour

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Exercise 4: Key Area 2. 4: Sex and Behaviour

1.Which row in the table best describes r-selected species?

Number of offspring / Offspring survival rate / Parental care
A / Many / Low / Little
B / Few / High / Extensive
C / Many / High / Extensive
D / Few / Low / Little

2.In some species of bird the females are larger than the males.

This is described as

Alekking

Breversed sexual dimorphism

Csexual dimorphism

Dfemale choice.

3.Eggs from leopard geckos kept in breeding cages were collected and incubated at two temperatures over five breeding seasons. When each new gecko hatched, its gender was noted. The graph below shows how temperature affected gender in the population.

How many females would be present in a population of 500 leopard geckos after four seasons at 32·5 °C?

A150

B200

C300

D350

4.The black belly stripe of great tit males (Parus major) is an important stimulus in territorial and courtship displays. Males with broader stripes make better parents and are more attractive to prospective mates. The width of the stripe is therefore correlated with male quality.

This stripe functions as

Aan honest signal

Ba sign stimulus

Ca fixed action pattern

Dan imprinting stimulus.

5. The red-winged blackbird (Agelaius phoenicius) is widely distributed in large areas of North and Central America. It prefers grassland habitats, particularly in marshy or wetland areas.

Territorial males show a form of polygamy called polygyny and may mate with and defend up to ten females in the territory, depending on the food resources available. The graph below shows the relative reproductive success of females mating with males that have from one to six mates.

(a)Describe the trend shown in the graph.

______

(b)How do the data justify the conclusion that it benefits females to mate with males that have the best territories?

______

(c)Natural selection is concerned with “survival of the fittest”.

Using the idea of optimal reproduction, explain why a male bird should favour polygyny over mating with a single female.

______

(d)In this species, investment in the young by the female is greater than by the male.

Suggest one way in which this greater investment is demonstrated.

______

6.The North American wild turkey (Meleagris gallopavo) shows distinct differences between males and females. The males have vividly-coloured, iridescent plumage. An experiment was carried out to investigate the effect of parasite infections on the amount of light reflected by the males’ plumage. Results are shown in the chart below: lower reflectance scores indicate duller plumage.

(a)What term is used to describe the differences between males and females?

______

(b)Describe the relationship between parasitic infection and the male birds’ plumage.

______

(c)The researchers have suggested that iridescent coloration in wild turkeys serves as an honest signal to females.

How will this influence mating success?

______

Total: ____/12

Self-Evaluation Key Area 2.5: Parasitism

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Exercise 5: Key Area 2. 5: Parasitism

1.A species of parasitic wasp (Nasonia vitripennis) lays its eggs in the larvae of flies where the eggs develop. This species displays a behaviour called “superparasitism” where, following the laying of eggs by one wasp, a second wasp may superparasitise the same host by also laying its eggs.

Researchers investigated the effects of superparasitism on the brood size and sex ratio of offspring in this species. Results were compared to a control that had been parasitised only once. Researchers were able to distinguish between the offspring of the first and second wasp.

Results are shown in the table below.

Offspring / Degree of Parasitism
Superparasitism / Single parasitism control
Wasp 1 / Wasp 2
Brood size / 18 ± 3 / 17 ± 4 / 20 ± 2
Percentage of males / 7 ± 2 / 22 ± 4 / 6 ± 1

The following statements refer to the data in the table.

1Superparasitism significantly increased the percentage of males produced by both wasp 1 and wasp 2.

2Superparasitism significantly increased the percentage of males produced by wasp 2 only.

3Superparasitism had no significant effect on brood size.

4Superparasitism significantly decreased the brood size produced by wasps 1 and 2.

Which of these statements are valid conclusions supported by the data?

A1 and 3

B1 and 4

C2 and 3

D2 and 4

2.The beef tape worm (Taenia saginata) lives within the small intestine of humans. For part of its life cycle, it does not have a digestive system. Therefore, the parasite is said to

Abe degenerate

Bbe a micro-parasite

Coccupy its fundamental niche

Dco-exist by resource partitioning.

3.Which line in the table below correctly describes the ecological niche of a parasite?

Niche / Host Specificity
A / Wide / High
B / Wide / Low
C / Narrow / High
D / Narrow / Low

4. The fundamental niche of a species

Aincludes the set of resources available in the absence of competitors

Bincludes the set of resources available in the presence of competitors

Cpermits coexistence in a community

Dpermits sharing of resources with other species.

5.The diagram below shows the life cycle of a parasitic worm that causes a disease in humans.

Which line in the table below correctly describes the roles of the other species in this parasite’s life cycle?

Definitive Host / Intermediate Host / Snail as a Vector
A / Snail / Human / No
B / Human / Snail / No
C / Snail / Human / Yes
D / Human / Snail / Yes

6.Discuss the concept of niche and how it applies to parasites.

7.Discuss factors that maximise the transmission of parasites.

(End of part 1. Subtotal: ___/25)

Exercise 5, part 2:

8.The figure below shows the life cycle of Plasmodium falciparum, a parasite that causes malaria in humans. The figure also shows stages in its life cycle targeted by two human vaccines, the zygote stage by Pfs25 and the sporozoite stage by RTS,S.