Which of the following situations constitute growth • The increase in size of the protoplasm of a plant cell placed in water • A teenaged human gains 2 kg in 4 months • A plant gains weight immediately after a heavy shower of rain • A plant increases in height by 2 cm in 2 years • A copper sulphate crystal increases in size • A dehydrated camel gains weight and increases in volume after taking a long drink of water
Distinguish between Growth and Development • After fertilization of an egg, what is the first process which occurs? • Do all the cells remain alike after division? • Make a list of the processes which contribute to growth and development of a multicellular organism. • State briefly what occurs during each process. - HW
Measuring Growth - considerations • Advantages and disadvantages of the methods listed – HW due 4 Feb 2013 • Growth measurements must be made at suitable intervals of time over a known period. • What would be a suitable interval for each of the dimensions mentioned in the table?
GROUP WORK • In pairs answer the following questions: • What is the importance of including units used? • List the limitations of the method you are investigating. • Record your results in a table/graph if necessary
Class tasks • Measuring length/height: find the average height/foot size, middle finger length etc. for the class. • Measure surface area: measure the surface area of the palm of your hand. • Fresh mass: measure the mass of potted plant in the school yard
Next Class! • Using the graph drawn answer the following questions: • What was the girl’s weight at age 10? • What was her weight at age 15? • What is the time interval between 10 and 15? • How much weight did the girl put on in this time interval? • Therefore what was her average rate of growth between age 10 and age 15? • What was the growth rate of the girl in the first year of her life after birth? • What was the growth rate of the girl for the period before birth?
Planning and Design Lab • Investigate the effect of water availability on growth rate of germinating seedlings