Biodiversity and the Distribution of Life Homework 1

Transcription

1 Unit 3 Homework

2 Biodiversity and the Distribution of Life Homework. Marsh marigold is a waterside plant which grows beside burns. The abundance of marsh marigolds was estimated in five sampling areas beside a burn in the Scottish borders. Average values of three abiotic factors were also calculated for each area. The results are shown in the table below: (a) (b) (c) What is meant by the term abiotic factor? () Name one abiotic factor which does not affect the abundance of marsh marigolds. () What is the relationship between Average soil nitrate concentration (ppm) and Abundance on marsh marigold? ()

3 2. Read the passage below and use the information to answer the questions which follow. (Adapted from Hostile Habitats, Scottish Mountaineering Trust, 2006). As you climb a mountain or hill, the vegetation gradually changes. In Scotland, trees and tall grasses in the glens are replaced on the mountain tops by lichens and dwarf mosses less than a centimetre high. The treeline is the maximum altitude at which trees can grow. Scottish hills have relatively little tree cover and so the treeline is not always obvious but it does form a real ecological boundary. If trees had not been cleared by humans in past centuries, the slopes below the treeline would be covered in forest. Low growing vegetation is dominant on the higher slopes. The factors which produce the treeline are not clearly understood but the average temperature during the growing season seems to be important. Under colder conditions, trees are at a disadvantage compared to low growing, denser vegetation. The growing tips of trees are fully exposed to high winds which cause physical damage and slow down growth of shoots by drying them out. High winds in wet conditions cause wind chill which can further damage shoots. In the case of low growing plants, these effects are reduced as their growing shoots are protected by the surrounding vegetation. The treeline in Scotland is generally lower than in other countries a similar distance from the equator. The exact height of the treeline varies across Scotland. The wet and windy conditions in the west of Scotland produce a treeline between 200 m and 450 m above sea level. In the east of Scotland, the treeline is between 500 m and 650 m above sea level. Other types of vegetation show similar effects, with mountain plants being found at lower levels on the west coast. (a) (b) Give two types of plants you might expect to find growing on mountain tops in Scotland. 2 () Most hills in Scotland do not have woodland present up to the potential treeline. Why is this? ()

4 (c) (d) (e) (f) (g) According to the passage, what factor might be important in determining how high up a hill trees can grow? () What two factors are needed to produce wind-chill? 2 () The passage states that, Low growing vegetation is dominant on the higher slopes. What advantage does this type of vegetation have which allows it to grow at higher altitudes than trees? () What is the average range of the height of the treeline across the whole of Scotland? From to m above sea level () In summer, red deer migrate to graze above the treeline. In which part of Scotland would they have to go higher to do this? ()

5 Biodiversity and the Distribution of Life Homework 2. The picture below shows the distribution of one biome across earth. (a) What is meant by the term biome? (b) Which biome is shown in the map above? (c) In Scotland we live in a decidous forest biome. The table below shows the average monthly rainfall in Scotland over the course of six months.

6 (d) Present this information as a bar graph by: (i) adding a suitable scale to both axis; (ii) adding labels to both axis; (iii) plotting the graph

7 2. Use words from the list to complete the following sentences. List population community habitat A pond provides a for a of many different types of organisms. Plants of the same species form a. 3. What term is used to describe the role that an organism plays within its community?

8 4. A study has shown that Scotland s river otter population is increasing after falling sharply over the last 40 years. Otters live along the banks of rivers, usually in reeds and gaps between tree roots. Fish are their main food. (a) What term is used for the place where otters live? (b) What disadvantage might otters have if reeds are removed from riverbanks?

9 Energy in Ecosystems Homework. The diagram below shows the transfer of energy through a food chain in a wood. The numbers represent the units of energy in the different populations of the food chain. a. Complete the table below using information from the diagram: Population Energy Content (units) Caterpillar Hawk 480 (2) b. 4% of the light energy reaching the oak tree is converted into new plant material. How much energy did the oak tree receive? Space for calculation units ()

10 2. A pyramid of biomass, including mussels, is shown below: a. Explain what is meant by a pyramid of biomass () b. In an investigation, mussels were found to eat an average of 600 g of plankton per day. This plankton contains 450 g of water. The dry weight of the plankton contains 20% protein. Calculate how much protein a mussel eats per day. Space for calculation g () c. A different food chain from the ocean is shown below: Plankton krill blue whale Which population in the food chain contains the least energy? ()

11 3. The diagram shows some of the stages in the nitrogen cycle: a. Complete the table by giving a number from the diagram to match each of the named stages: Stage Number Absorption Death Nitrification Decomposition (2) b. Name chemical X () c. Name the type of organism responsible for stage 3 () d. Name three uses of Nitrogen by the plant ()

12 Energy in Ecosystems Homework 2 Extended Response Questions. The pictures below show a food chain which is also represented by two types of pyramid. Name the type of pyramid X. Explain why both pyramids are correct for this food chain. (5) 2. Write notes on how animals can reduce intraspecific competition using the following methods: i. co-operative hunting () ii. dominance hierarchy (2) iii. territorial behaviour (2) (5)

13 Sampling Techniques Homework. Three groups of students used quadrats to carry out a survey on the distribution of mussels on different areas of a shore. Each quadrat measured 50 cm 50 cm. (Four quadrats = m2). The positions of the quadrats and the number of mussels found is shown below for each group. (a) Complete the following table with the results from group C. Space for calculation.

14 (b) Which group has made an error in their sampling technique which makes their results less reliable than other groups? State the error this group has made and describe an improvement which would increase the reliability of their results. Group Error Improvement 2. Marsh marigold is a waterside plant that grows beside burns. The abundance of marsh marigolds was estimated in five sampling areas beside a burn in the Scottish borders. Average values of three abiotic factors were also calculated for each area. The results are shown in the table below. (a) Name one abiotic factor which does not affect the abundance of marsh marigolds.

15 (b) The soil ph for each sampling area was measured using a ph meter with a probe which was pushed into the soil to obtain each reading. (i) Identify a possible source of error in measuring a named abiotic factor and suggest how to minimise it. Abiotic Factor Source of error How to minimise it 2 (ii) How was the measurement of the abiotic factors in the survey carried out to reduce the effect of atypical results?

16 3. Two groups of pupils set pitfall traps in the school gardens to sample invertebrates living there. The diagrams below show the invertebrates collected by the pupils. (a) Complete the following key using information from the diagrams. 2

17 (b) Give two features of the beetle mentioned in the key.

18 Adaptation, natural selection and evolution Homework. In African grasslands impala, giraffe and zebra feed on Acacia trees. Impala and zebra also graze on grasses. (a) State one way that competition for food is reduced between zebras and giraffes. (b) The Acacia tree is adapted to withstand long periods of drought. Suggest an adaptation the Acacia tree may show that allows it to survive long, dry periods.

19 2 Charles Darwin visited the Galapagos Islands. He found different species of finch on the different islands. The following gives information on the size and shape of beaks and the island habitats of two of the Galapagos finches. Size and shape of beak Long and narrow Short and wide Habitat Rotting logs that provide food for insects Trees and shrubs that provide seeds and nuts (a) State which finch eats insects and give a reason for your answer. (b) Identify two ways in which competition between finch A and finch B is reduced.

20 3. Down s Syndrome is an example of a condition caused by a change to the chromosomes. (a) What is the correct term for a change to the chromosomes? (b) The following table shows the risk to women of different ages of having a baby with Down s Syndrome. How many times greater is the risk to a 42 year old woman of having a Down s Syndrome baby, compared to an 8 year old woman? Space for calculation. times greater

21 (c) Complete the line graph below by: completing the scale on the y-axis; 2 adding a label to the y-axis; 3 plotting the graph. 4. Mutation rate can be increased artificially using chemical agents. Give another example of a mutagenic agent.

22 Adaptation, natural selection and evolution Extended Response Questions The diagram below shows the two different forms of the peppered moth Biston betularia on the bark of a tree located in an unpolluted area. Name and describe the process by which the black form of the moth became the most common form in polluted areas of Scotland. 5

23 Give an account of the importance of isolating mechanisms, mutations and natural selection in the evolution of new species. 5

24 Human Impact on the Environment Homework. The bar chart shows the average annual losses in yield caused by insects and disease in the production of three crops in Scotland. a) Which crop has the lowest combined percentage loss from these two causes? () b) The total crop of oats harvested was tonnes. Calculate the yield of oats which would have been produced if insects and disease had not affected the plants. () c) Explain why it would not be a valid conclusion to say that disease caused more tonnes of oats to be lost than any other of the crops named. ()

25 d) Oilseed rape is a common crop which has average annual losses of 9% to insects and 2% to disease. Use this information to complete the bar chart by adding labels and bars in the space provided. () 2. Read the following passage and answer the questions based on it. Adapted from GM Organisms by John Pickrell, Genetic modification (GM) of crops began with the discovery that the soil bacterium Agrobacterium could be used to transfer useful genes from unrelated species into plants. The Bt gene is one of the most commonly inserted. It produces a pesticide toxin that is harmless to humans but is capable of killing insect pests. Many new crop types have been produced. Most of these are modified to be pest, disease or weedkiller resistant, and include wheat, maize, oilseed rape, potatoes, peanuts, tomatoes, peas, sweet peppers, lettuce and onions. Supporters argue that drought resistant or salt resistant varieties can flourish in poor conditions. Insect-repelling crops protect the environment by minimising pesticide use. Golden rice with extra vitamin A or protein-enhanced potatoes can improve nutrition. Critics fear that GM foods could have unforeseen effects. Toxic proteins might be produced or antibiotic-resistance genes may be transferred to human gut bacteria. Modified crops could become weedkiller resistant superweeds. Modified crops could also accidentally breed with wild plants or other crops. This could be serious if, for example, the crops which had been modified to produce medicines bred with food crops. Investigations have shown that accidental gene transfer does occur. One study showed that modified pollen from GM plants was carried by the wind for tens of kilometres. Another study proved that genes have spread from the USA to Mexico.

26 a) What role does the bacterium Agrobacterium play in the genetic modification of crops? () b) Crops can be genetically modified to make them resistant to pests, diseases and weedkillers. Give another example of genetic modification that has been applied to potatoes. () c) Explain why a plant, which is modified to be weedkiller resistant could be: i. Useful to farmers () ii. A problem for farmers () d) Give one example of a potential threat to health by the use of GM crops. () e) What is your opinion on GM crops? Give at least one reason for your answer. ()

27 Human Impact on the Environment Homework 2. When greenfly feed on cotton plants, they release a sticky mixture of sugars onto the leaves. This causes problems in the cotton industry. Researchers tested three wild yeasts to find a strain which could digest and remove the sugars without harming the cotton plants. The results are shown on the chart below. a) Which sugar was completely digested by all the strains of yeast? b) By comparing the results of all three strains of yeast, which sugar was the least well digested?

28 c) Which strain of yeast would be the most useful in solving the problem caused by the greenfly? Give a reason for your answer. Strain Reason 2. Read the following passage and answer the questions based on it. Adapted from GM Organisms by John Pickrell, Genetic modification (GM) of crops began with the discovery that the soil bacterium Agrobacterium could be used to transfer useful genes from unrelated species into plants. The Bt gene is one of the most commonly inserted. It produces a pesticide toxin that is harmless to humans but is capable of killing insect pests. Many new crop types have been produced. Most of these are modified to be pest, disease or weedkiller resistant, and include wheat, maize, oilseed rape, potatoes, peanuts, tomatoes, peas, sweet peppers, lettuce and onions. Supporters argue that drought resistant or salt resistant varieties can flourish in poor conditions. Insect-repelling crops protect the environment by minimising pesticide use. Golden rice with extra vitamin A or

29 protein-enhanced potatoes can improve nutrition. Critics fear that GM foods could have unforeseen effects. Toxic proteins might be produced or antibiotic-resistance genes may be transferred to human gut bacteria. Modified crops could become weedkiller resistant superweeds. Modified crops could also accidentally breed with wild plants or other crops. This could be serious if, for example, the crops which had been modified to produce medicines bred with food crops. Investigations have shown that accidental gene transfer does occur. One study showed that modified pollen from GM plants was carried by the wind for tens of kilometres. Another study proved that genes have spread from the USA to Mexico. a) What role does the bacterium Agrobacterium play in the genetic modification of crops? b) Crops can be genetically modified to make them resistant to pests, diseases and weedkillers. Give another example of genetic modification that has been applied to potatoes.

30 c) Explain why a plant, which is modified to be weedkiller resistant could be: useful to farmers. a problem for farmers.

31 3. Environmental protection analysis was carried out on water samples from three burns. The Mains Burn had the highest ph at 8.0. It also had the highest oxygen saturation at 94% compared to Bell s Burn which had the lowest at 65%. The Hatchery Burn had the lowest value for suspended solids at 4.0 mg/l, with an oxygen saturation of 9.5%. Bell s Burn had a suspended solids reading of 5.6 mg/l and the lowest ph at 7.7 compared to a value of 7.9 for the Hatchery Burn. The highest reading for suspended solids was recorded in the Mains Burn with a value of 6.0 mg/l. Complete the following table with the data in the passage using suitable column headings. 3