Summative assessment for Unit Growth, development and motion Name: _________________________________ Date: ____________ 11.2.3.2 describe how the scientific understanding of aging develops as new data emerges 11.1.6.1 explain the mechanism of muscle contraction by the sliding filament theory 11.1.6.2 establish a relationship between the structure, location and general properties of fast and slow muscle fibres 1. (i) Which of the following changes are common to aging? a. Slower reaction time for complex tasks b. Declines in manual dexterity c. A smaller range of motion d. All of the above [1] (ii) Stem cell therapy is based on the ability to reprogram cell growth. Assuming each theory has merit, which of the following “Theories of aging” can be controlled by stem cell therapy? a. simple deterioration (wear and tear theories) b. non-programmed ageing (non-adaptive or passive ageing) c. programmed ageing (also known as adaptive ageing, active ageing, or ageing-by-design) d. Ageing Genes Theory [1] 2. (i) The figures below labeled A, B, and C represent 3 different types of muscle fibers. The darker areas represent red area while the lighter ones represent white areas. A B C Which of the following statements is correct regarding the figures. a. A is a fast twitch type, contains a high number of mitochondria and is used for long distance running b. B is an intermediate type of muscle fiber, has low amount of mitochondria and is ideal for long and fast burst of speeds. c. C is a fast slow twitch type of fiber that contains a low amount of mitochondria, is high in glycogen and is good for short and rapid bursts of speed. d. A and B are both non rapid twitch fibers, have relatively high numbers of mitochondria and good blood supply. [1] (ii) The table compares three types of muscle tissue. Fill the blanks with the appropriate information. Cardiac Cell structure Type of muscle Smooth no striations Appearance in the light microscope Organisation of contractile proteins inside the cell multinucleate organized into parallel bundles of myofibrils Shape of cells long, unbranched cylinder Control Distribution in the body Striated neurogenic heart [3] 3. Figure 3.1 shows part of a myofibril form skeletal muscle. Fig. 3.1 (i) Describe one feature that is visible in the diagram, which show that the myofibril is contracted. ............................................................................................................................................................... ............................................................................................................................................................... [1] (ii) The sliding filament theory gives a plausible explanation for how muscle contraction occurs. Describe how the following structures/substances contribute to muscle contraction a. Troponin ............................................................................................................................................................... ............................................................................................................................................................... [1] b. Myosin head ............................................................................................................................................................... ............................................................................................................................................................... [1] d. Actin fibril ............................................................................................................................................................... ............................................................................................................................................................... [1] e. ATP ............................................................................................................................................................... ............................................................................................................................................................... [1] e.Tropomyosin ............................................................................................................................................................... ............................................................................................................................................................... [1] (iii) Interneuronal synapses are those found between neurones, such as those in a reflex arc. Describe the similarities and differences between the structure and function of interneuronal synapses and neuromuscular junction. …………………………………………………………………………………………………………… …………………………………………………………………………………………………………… …………………………………………………………………………………………………………… …………………………………………………………………………………………………………… …………………………………………………………………………………………………………… ……………………………………………………………………………………………………….. [3]
