Answer all questions in the spaces provided. The drawings show three cells. Two of the cells are from multicellular organisms and one is a single-celled organism.
The three organisms belong to different kingdoms. 30 pm 60 pm 1 pm cell A cell B cell C Name the kingdom to which each organism belongs. In each case, give one feature of the cell, visible in the drawing, which is characteristic of the kingdom and which helps to distinguish it from cells of organisms belonging to the other two kingdoms. Kingdom Feature (6 marks) 6 2Division of the nucleus by meiosis produces haploid cells from a diploid cell. Nuclei produced by mitosis have the same number of chromosomes as the parent nucleus.
What is the biological importance of reducing the chromosome number when the cell divides by meiosis? (2 marks) The table gives one difference between meiosis and mitosis. Complete the table by giving three further differences. Meiosis Mitosis Reduces the chromosome number Maintains the same chromosome number as in the parent nucleus 3 4 (3 marks) 5 Turn over Phytoplankton are microscopic photosynthesising organisms which live in water.In favourable environmental conditions they have a very high rate of reproduction. They are eaten by microscopic animals called zooplankton.
In an investigation, samples of water were removed from a lake at intervals over a twelve-month period and the biomasses of these organisms were determined. The results are shown in the graph. Phytoplankton Biomass Zooplankton Jan Feb Mar Apr May Jun Aug Sep Oct Nov Dec Month The diagram shows the relationship between the biomass of the phytoplankton and the biomass of the zooplankton for one of the months during this investigation.Zooplankton Phytoplankton Use the graph to give one month in which this relationship would have been found. (1 mark) 5 Explain why the biomass of the primary consumers is less than the biomass of the producers in most communities.
(3 marks) Explain why the biomass of the phytoplankton in the lake could be less than that of the zooplankton, as shown in the diagram
