thebiotutor.com 1 AB variety of living organisms Time: 46 minutes Total marks available: 46 Total marks achieved: Andy Todd

Transcription

1 thebiotutor.com 1 AB variety of living organisms Time: 46 minutes Total marks available: 46 Total marks achieved:

2 Q1. (a) The table shows four different groups of organisms. Complete the table to give an example for each group. (4) (b) Different groups have different features. Complete the table below to show if the feature is present in all, some or none of each group. Some of the table has been completed for you. (3) (c) (i) Give one way in which the structure of a virus differs from a bacterium. (1)

3 (ii) Bacteria and viruses can act as pathogens. Give an example of a disease caused by a virus. (1) (Total for question = 9 marks)

4 Q2. All organisms share common basic characteristics. Some of these are given below with a simple description. (a) Complete the table by adding the missing characteristics and the missing descriptions. (4) (b) Organisms can be classified into different groups depending on their structure. State two ways in which (i) a typical plant cell differs from a typical animal cell (ii) a bacterium differs from a virus (2) (2) (Total for question = 8 marks)

5 Q3. (a) Complete the table to show the characteristic features of the three groups of organisms. Use a tick if the group has the characteristic and a cross if the group does not have the characteristic. The first box has been done for you. (4) (b) The table below shows some characteristics shared by most animals. Complete the table by giving the missing characteristics and examples. (4) (c) Another characteristic shown by animals is the ability to respond to their surroundings.

6 For example, a person may withdraw their hand from a hot object. Describe the sequence of events that cause this response. (5) (Total for question = 13 marks)

7 Q4. (a) Although plants and animals have many different features, they also have some features in common. The table lists some features. In each box, place a tick if the feature is present or a cross if the feature is absent. One has been done for you. (4) (b) Organisms that cause disease are known as pathogens. Give two groups of organisms that include pathogens. (2) (Total for question = 6 marks)

8 Q5. The following organisms can be classified into major groups. (a) From the list above give the name of (i) a bacterium... (ii) a fungus... (iii) a flowering plant... (iv) an animal... (4) (b) Viruses are not included in most classification systems. (i) Give three ways in which viruses differ from other living organisms. (ii) Give one example of a disease caused by a virus, name the organism it infects and describe its effect on the organism. Disease... Organism infected... Effect (3) (3) (Total for question = 10 marks)

9 Q1. In part (a) this question examined knowledge about different groups of organisms and was well answered by most students. The most common responses were names that appear in the specification such as humans, Mucor, Lactobacillus and Amoeba, but there were many other acceptable alternatives. The names of diseases were not accepted. Part (b) was clearly more challenging with only the very best students gaining all three marks. In part (c)(i), most students were aware of a difference between the structure of viruses and bacteria. The most common answer made reference to the protein coat. Some students believe that a difference is the lack of a nucleus but this is also true of bacteria so was not credited. In part (ii), many students lost credit by giving the name of a virus, frequently HIV, rather than a disease caused by a virus.

10 Q2. This question part a) required candidates to complete a table on the characteristics of living organisms. Many candidates gained full marks for this item. Part b) required them to identify how a typical pant cell differs in structure from a typical animal cell and how a bacterium differs in structure from a virus. Most candidates could give two ways that a plant cell differs from an animal cell but they did less well on how a bacterium differs in structure from a virus. Q3. Part (b) asked candidates to complete a table to show the features of bacteria fungi and viruses. Most scored well on this item and on (b) which required linking characteristics of life with examples. In part (c) candidates had the opportunity to describe the events in the withdrawal reflex. Most who had learnt the components scored well. Q4. This question required candidates to recognise features of plants and animals and many were able to gain full marks. The second part of this question asked for two groups of organisms that include pathogens and most could give these. Some candidates gave an example of a pathogen and thus were not credited. Q5. Part (a) required candidates to select examples of major groups of organisms from the list provided. Most were able to do this but some wrongly selected Amoeba as an animal and Mucor as a bacterium. In (b), many candidates were able to give three ways in which viruses differed from other living organisms. Common answers referred to lack of respiration, movement, sensitivity or excretion as well as being smaller and only reproducing inside other organisms and having a protein coat. In (c), most could name a viral disease and give the organism it infects along with its effects. Some answers did not give the organism infected, stating "the immune system" but not giving the organism.

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12 Q2.

13 Q3.

14 Q4. Q5.

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