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Seeds may be classified as either endospermic or non-endospermic, based on whether food is stored in endosperm or cotyledon tissue - Leaving Cert Biology - Question 15 - 2015
Question 15
Seeds may be classified as either endospermic or non-endospermic, based on whether food is stored in endosperm or cotyledon tissue. Seeds may also be either monocoty... show full transcript
Worked Solution & Example Answer:Seeds may be classified as either endospermic or non-endospermic, based on whether food is stored in endosperm or cotyledon tissue - Leaving Cert Biology - Question 15 - 2015
Step 1
Suggest why the measurement of dry mass is preferred in these investigations.
Answer
The measurement of dry mass is preferred because it provides a more accurate representation of the actual biomass of the tissue, eliminating the variability caused by water content. By measuring dry mass, researchers can more reliably compare the growth rates and nutritional status of seeds under investigation.
Step 2
Explain why the dry mass of the endosperm tissue decreases over the three weeks.
Answer
The dry mass of the endosperm tissue decreases over the three weeks due to its depletion as food reserves are utilized to support the growing embryo. As the embryo develops, it draws upon these stored nutrients for energy and building materials, leading to a decrease in the mass of the endosperm.
Step 3
Step 4
Would you expect the total dry mass of the seed (embryo plus endosperm) to have remained the same up to A? Explain your answer.
Answer
No, I would not expect the total dry mass of the seed to remain the same up to A. As the embryo grows, it consumes the nutrients stored in the endosperm, leading to a reduction in the total mass. The dry mass decreases due to the respiration processes occurring in the embryo, which uses food reserves while the endosperm mass also diminishes.