Tut 1 - Cell Ultrastructure (Teacher)

St Andrew’s Junior College Cell Ultrastructure 2021 H1 Biology 1 Full Name: Civics group: 21S Index no.: Date: Core Idea 1: The Cell and Biomolecules of Life Tutorial 1 Cell Ultrastructure MCQ ANSWERS 1 2 3 4 5 6 7 8 9 10 D C B B A B A C C C 11 12 13 14 15 16 B D A A B A 1 Which size ranges can be viewed using a light microscope? A 4 only B 1 and 2 only C 2 and 3 only D 3 and 4 only 2 The diagram shows a chloroplast drawn from an electronmicrograph. The length of the chloroplast from X to Y is 5000 nm. What is the magnification of the drawing of the chloroplast? A x100 B X1000 C X10 000 D X100 000 Refer to diagram on lecture notes pg 6 Working: Magnification = image / actual = 5.7 cm / 5000 nm = 5.7 x 10-2 m / 5000 x 10-9 m = 1.14 x 104 ~ x 10 000 Unit is in nm, hence indicate actual size of chloroplast.

St Andrew’s Junior College Cell Ultrastructure 2021 H1 Biology 2 3 The electronmicrograph is of a chloroplast. The length of the chloroplast image along the line shown is 90 mm. The magnification of the organelle is x300,000. What is the actual length of the chloroplast? A 0.3 µm B 3.0 µm C 30 µm D 300 µm 4 You are told that the cells on a microscope slide are plant, animal, or bacterial. You look at them through a microscope and see cell walls and membrane-bound organelles. You conclude that the cells are A Bacteria cells B Plant cells C Bacteria and plant cells D Bacteria, plant, and animal cells Working: Actual size = image / magnification = 90 mm / 300,000 = 90,000 µm / 300,000 = 0.3 µm mm is x10-3 m, µm is x10-6 m indicate either Plant cells (cellulose cell wall) or bacterial cell (peptidoglycan cell wall) - from Qn cannot tell what type of material the cell wall is made up of without the use of specific dye staining - Presence of cell wall eliminate animal cell (which has no cell wall) from answer. confirmed Plant cells (prokaryotes e.g. bacteria lack membrane-bound organelles)

St Andrew’s Junior College Cell Ultrastructure 2021 H1 Biology 3 5 Which features enable an organism to be identified as a prokaryote? 1 cell wall →both eukaryote (plant cells) & prokaryote (bacteria) have cell wall 2 circular DNA → only prokaryote (bacteria) has circular DNA; eukaryote has linear DNA 3 nucleus → only in eukaryotic cell; prokaryote does not have membrane-bound nucleus but has nucleoid – region where the DNA / genetic material is located. 4 ribosomes → both prokaryote and eukaryote have ribosome but it is 70S ribosomes in prokaryote, 80S ribosomes in eukaryote A 2 only B 3 only C 1 and 4 only D 2 and 4 only 6 A scientist carried out an experiment to separate the organelles in an animal cell by mass. The scientist mixed the cells with a buffer solution which had the same water potential as the cells. He then broke the cells open with a blender to release the o