Question

29. An investigation was carried out into competition between two species of grass,
Bromus madri-
tensis and B. rigidus. Equal numbers of seeds of B. madritensis were sown in a number of different
pots. In each pot, an equal number of seeds of B. rigidus was then sown a different number of
days after B. madritensis. The results are shown in the graph below.
Given that the total dry mass of plant material was the same in each pot, summarize the main
conclusions that can be drawn from this investigation. Suggest an explanation for the results
when the delay before sowing B. rigidus was 30 days.
100-
80
60-
Percentage
contribution of
B. madritensis
to total dry mass
after 45 days
40
20-
0
0
20
30
10
Delay before planting B. rigidus/days

Answer 1

3,4,5 Triangles are right triangles, Answer Anon
the Paper says 12:16:20 which is proportinate
to said ratio, hence the answer is B

Answer 2

The competition that exists between Bromus madritensis and B. rigidus is for food, sunlight and space.

What is biological competition?

Biological competition refers to the interaction between two or more organisms of the same or different species in which both require a common resource that is in limited in their environment.

The effect of the competition between the two species of grass,

Bromus madritensis and B. rigidus is illustrated I. the graph.

Based on the graph, it can be seen that after a delay of 30 days, Bromus madritensis contributed to almost 100% of the total dry mass of the grass after 45 days.

This suggests that the available space and nutrients have been taken up completely by Bromus madritensis.

Therefore, the competition that exists between Bromus madritensis and B. rigidus is for food, sunlight and space.

Learn more about biological competition at: https://brainly.com/question/9436462

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