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In 5 points, Discuss aquatic, terrestrial and arboreal habitats in relation with adaptation and survival of organisms in these habitats
Under which of the following conditions is the R form of Hb favored?
a.At low O2 partial pressures, as in the lungs.
b.At high O2 partial pressures, as in muscles.
c.At low O2 partial pressures, as in muscles.
d.At high O2 partial pressures, as in the lungs.
e.The R form of Hb does not depend on the presence of O2
Identify and describe two ways that you can reduce the effectiveness of an enzyme
1.Write out the floral formula and description for the Ray floret.
2.Write out the floral formula and description for the Disc floret.
The population of disease doubles every 90 minutes when growing under ideal conditions.
A different starter culture was prepared containing 1 * 10 7 cells.
Sketch a growth curve on a graph (with axes ‘log10 number of cells’ on the y axis and ‘time in hours’ on the x axis) you would expect for the yeast culture over the first 15 hours .
Student prepared to start a culture using 2.5*10-3g yeast cells in 1dm3 nutrient broth.
The average mass of yeast cell is 2*10 -11g.
calculate the number of cells in the starter culture
Give your answer in standard form
A light microscope can be used to observe yeast cells.
State the equipment that would be needed in addition to a microscope to measure the average time diameter of yeast cells.
The student wanted to study the effect of the different sugars in the rate of growth of a yeast population.
They used to colorimeter to measure the absorbance of a culture of yeast cells.
The absorbance of the yeast culture is proportional to the concentration of yeast cells.
As the yeast is multiplied it was necessary to dilute the sample to obtain a reading on the colorimeter.
Describe how the student could 1cm3 cubed pippets and 10cm3 measuring cylinders to dilute the sample so that it was 10,000 times less concentrated .
A student stated:
- The rates of respiration with glucose maltose and sucrose were very similar.
- The yeast could not hydrolyse diasaccharides.
Evaluate the students statements.
Explain why early eukaryotes were able to grow more quickly than cells that did not possess mitochondria.
