11. (a) (i) Why are plants known as producers? (ii) What is the main source of energy for living things? (iii) What term is given to a diagram showing a number of interlinked food chains? (b) Over the years many new plant and animal species have spread to Ireland - Leaving Cert Biology - Question 11 - 2017

The main source of energy for living things is the Sun. It provides the necessary energy for photosynthesis in plants, which in turn supports the entire food web.

The term given to a diagram showing a number of interlinked food chains is 'food web.' It illustrates how various organisms in an ecosystem are interconnected through multiple feeding relationships.

The plant spreading along the river banks is the giant hogweed. Its invasive growth can significantly alter the local ecosystem.

The giant hogweed can cause skin damage by producing a toxic sap that, when exposed to sunlight, can lead to severe skin burns and blisters.

The term 'species' refers to a group of organisms that can interbreed to produce fertile offspring. Members of a species share common characteristics and genetic material.

Zebra mussels originated from the Black Sea region. They have since spread to various waterways, including those in Ireland.

The species attacking the earthworms are the New Zealand flatworms. These flatworms feed on native earthworms, disrupting their populations.

Earthworms are important in the soil for several reasons:

1. They improve soil drainage and aeration by burrowing through it, allowing air and water to penetrate more easily.
2. Earthworms contribute to soil fertility by breaking down organic matter and facilitating nutrient cycling.

One resident animal that is not native to Ireland is the pig, which has been domesticated and brought to Ireland by humans.

The ecosystem could be a grassland, forest, or freshwater habitat, depending on the specific study context.

One plant from that ecosystem could be the oak tree, and one animal could be the red fox.

A quantitative survey is a method used to count or estimate the number of organisms present in a specific area or ecosystem. It involves systematic sampling techniques to ensure accuracy.

To carry out a quantitative survey, I used the quadrat method. I randomly placed quadrats in the study area and counted the number of individuals of the chosen plant or animal species within those quadrats. I then extrapolated the data to estimate the overall population size in the entire area.