The effect of temperature on development of organisms (13)

Question 1

Describe an experiment that could be carried out to investigate effect of temperature on growth of duckweed (plants):

Answer 1

1)Use 5 different temperatures (20,23,26,29,32) controlling with a water bath
2)Same age and source of duckweeds, as well as volume and concentration of solution they’re kept in
3)Measure length of roots 3 days after being placed in set temperature, do the same 7 days after
4)Repeat 3 times for each temperature for reliability
5)Divide change in length by time to measure growth

Question 2

Control variables (for brine shrimp):

Answer 2

-Number of brine shrimp eggs
-Light intensity
-Volume of water and sea salt used
-Time the brine shrimp are left there for
-Age and species

Question 3

Devise an investigation to see effect of temperature on hatching of brine shrimp:

Answer 3

1)Set up water baths at temperatures 10,15,20,25,30, repeat 3 times at each one for reliability
2)Ensure variables like age/species of brine shrimp, light intensity, volume of water and sea salt used is controlled, as well as time organisms are left there for (e.g. 24 hours)
3)Pick up approximately 40 eggs and place them in water, use magnifying glass to count
4)The next day count the number of hatched larvae in each of the beakers, shine a light at the beaker and the larvae will swim towards the light
5)Record the number of larvae that have successfully hatched for each temperature

Question 4

Ethical considerations:

Answer 4

.Must return shrimp to their natural habitat after use
.Don’t use excessive temperature and light intensity
.Storing them in conditions that replicate their natural environment