Biology Standard level PaPer 1 Monday 17 May 2010 (afternoon) 45 minutes INSTRUCTIONS TO CANDIDATES
• Do not open this examination paper until instructed to do so. • Answer all the questions. • For each question, choose the answer you consider to be the best and indicate your choice on
the answer sheet provided.
15 pages ©International Baccalaureate Organization 2010
– 2 – 1. What does a small standard deviation signify? A. B. C. D. The data is not correlated. The data is widely spread around the mean.
The data shows a close relationship between two variables. The data is clustered closely to the mean value.
In a cell, what is the effect of a largesurface area to volume ratio? A. B. C. D. Slower rate of exchange of waste materials Faster heat loss Faster rate of mitosis Slower intake of food
How can cells in a multicellular organism differentiate? A. B. C. D. They express some of their genes but not others. They all have a different genetic composition. Different cells contain a different set of chromosomes. Differentcells do not have some of the genes.
– 3 – 4. The diagram below shows a bacterium.
What structure does the part labelled X identify? A. B. C. D. Nucleus Nucleoid Nucleolus Nuclear membrane
What do prokaryotic cells have that eukaryotic cells do not? A. B. C. D. Mitochondria 70S ribosomes HistonesInternal membranes
– 4 – 6. What happens during the G2 stage of interphase? A. B. C. D. Homologous chromosomes pair Synthesis of proteins Homologous chromosomes separate Replication of DNA
What is a role of sulfur in living organisms? A. B. C. D. Formation of proteins Formation of carbohydrates Formation ofteeth Transmission of nerve impulses
– 5 – 8. Which molecules form the nucleotide marked in the diagram? 5’ end A T
T 3’ end
A Structure of DNA 5’ end
A. B. C. D.
phosphate, deoxyribose and nitrogenous base phosphorus, ribose and nitrogenous base phosphorus, deoxyribose and guanosinephosphate, ribose and guanine
– 6 – 9. Which enzyme catalyzes the elongation of the leading strand?
Synthesis of leading strand 5’ 3’ Synthesis of lagging strand
[Source: image from W K Purves, et al., (2003) Life: The Science of Biology, 4, Sinauer Associates (www.sinauer.com) and W H Freeman(www.whfreeman.com)]
A. B. C. D.
RNA polymerase Helicase DNA polymerase Ligase
10. Which of the following is a function of cellulose in plants? A. B. C. D. Storage of fat Formation of mitochondria Storage of energy Formation of cell walls
11. Which of the following is the best definition of cell respiration? A. B. C. D. A process needed to use energy, inthe form of ATP, to produce organic compounds A process used to provide oxygen to the atmosphere A controlled release of energy, in the form of ATP, from organic compounds in cells A controlled release of energy in the production of food from organic compounds
– 7 –
12. The graph below shows the effect of temperature on the separation of thestrands in DNA to form single strands. The temperature at which 50 % of the DNA is single-stranded is called the melting temperature (TM ). 100 90 80 70 60 50 40 30 20 10 0 –10
% single-stranded DNA
50 60 70 80 Temperature / °C
What do the results show? A. B. C. D. When the temperature reaches 85 °C there are no more...
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