Organisms and Their Environment
96 questions· page 1 of 10
The total mass of plastics produced globally in the year 2020 was 367 million tonnes.
It is estimated that 3% of all plastics produced globally each year enters the ocean as plastic pollution.
Calculate the total mass of plastic pollution that is estimated to have entered the ocean during the year 2020.
______
Some packaging is made from biodegradable carbohydrates.
Microorganisms break down larger carbohydrate molecules into smaller molecules.
Identify this process and name one type of microorganism that is involved.
Most plastics that enter ecosystems as pollution are non-biodegradable.
Describe the harmful effects of non-biodegradable plastics on both aquatic and terrestrial ecosystems.
Woodland ecosystems are often managed by humans.
If trees in a woodland are chopped down, they can then be:
- burned
- removed and made into objects
- left in the ecosystem.
Compare the effects of these three different forms of management on the woodland ecosystem itself and more widely on the planet.
______
The number of individuals in a population can vary with time.
Table 8.1 shows how the global populations of humans and tigers are estimated to have changed between 1970 and 2000.
Table 8.1
| year | estimated global population: humans | estimated global population: tigers |
|---|---|---|
| 1970 | 3.6 billion | 35 000 |
| 2000 | 6.0 billion | 5 000 |
Suggest factors that may be causing these changes in the two populations and how the changes may be linked.
In 2010 the population of tigers had dropped to an estimated 3200.
Thirteen countries in which tigers live signed an agreement to double their tiger populations by 2022.
Explain why it is important to increase tiger populations and suggest ways of doing this.
The total mass of carbon dioxide released for each food in the study included the mass released
- during production of the food by farming
- after the food left the farm and before it was eaten.
Suggest and explain how human activity may result in the release of carbon dioxide after food has left the farm on which it was produced.
A farmer decides to change production from lamb to beans.
Calculate the percentage change in carbon dioxide released per kg of food produced.
______ %
An increasing number of people in some countries choose to eat a diet consisting only of plants.
Use the results in the table and your scientific knowledge to explain how this choice of diet may benefit the environment.
Organisms in a food web can be classified into different trophic levels based on their feeding relationships.
Explain the feeding relationships of named organisms at different trophic levels in this food web.
Describe how energy flows into and through a food web. Explain how this will determine the biomass of organisms at different trophic levels.
During this period of 18 years, the total amount of electricity produced each year by the 32 countries increased.
Suggest one change in the processes used by these countries to produce electricity that may account for the trends shown in the graph.
Pollution of the air by each of the gases named in the graph leads to harmful effects on ecosystems.
Suggest and explain the positive effects on ecosystems of the trends shown in the graph.
The population of one species of fish decreased from 1385 to 28 over this period.
Calculate the percentage decrease in the population of this species of fish.
______ %
The scientists who carried out the surveys suggested that the fish population might recover if conservation actions are taken.
Suggest one possible conservation action that could be recommended by the scientists and describe how they could find out whether this action is successful.