Homeostasis

The body controls its internal environment. One example of this is control of the concentration of the blood.

Give the name for controlling the internal environment.

Give the name for controlling the concentration of the blood.

A person entering a warm environment may become dehydrated as the concentration of the blood changes. Explain how the concentration of their blood is restored.

A person’s response to a changing environment involves communication by nerves and by hormones. State three differences between communication by nerves and communication by hormones.

One of the largest land mammals ever known is an extinct species of rhino that lived in Mongolia. The diagram compares the size of the extinct rhino with an existing rhino.

Using the scale on the diagram, calculate the shoulder height of the extinct (large) rhino. Give your answer in metres.

height of shoulder =_........ metres

Some people think that the large rhino became extinct because of global warming. Suggest how global warming could have made it difficult for the large rhino to maintain a constant body temperature.

Suggest two factors, other than global warming, that may have caused the large rhino to become extinct.

Name the process that maintains a constant internal environment in the body.

The diagram shows a section through human skin.

Explain how part A helps a person to maintain a constant body temperature when they enter a warm place.

Explain how part B helps a person to maintain a constant body temperature when they enter a warm place.

The body controls the water content of the blood.

Name this process.

Name the organ that controls the water content of the blood.

When trees lose leaves, they fall to the ground and form leaf litter. The leaf litter provides food for many animals. The diagram shows a food web that includes leaf litter.

Use information in the food web to complete the table. The first one has been done for you.

The following apparatus is called a Tullgren funnel. It is used to sample the number of animals living in leaf litter. The animals move away from the light and fall into the collecting pot.

A student used a Tullgren funnel to sample the number of millipedes living in leaf litter in two areas of a forest. The student took leaf litter from 5 quadrats in the centre of the forest and from 5 quadrats near the edge of the forest. The table shows the student’s results.

One stimulus that the millipedes respond to in the Tullgren funnel is light. Suggest two other stimuli that might cause millipedes to fall into the collecting pot.

State the difference in the number of millipedes found in the leaf litter samples from the two areas of the forest and suggest two reasons for this difference.

The student collects leaf litter using a quadrat. Draw a quadrat in the space below.

The photograph shows a bird called a parakeet.

Parakeets eat seeds. Parakeets can be eaten by birds of prey called raptors. Use this information to draw a food chain.

Many seeds contain starch. Suggest what happens to starch in the gut of a parakeet.

The graph shows the volume of oxygen used by a resting parakeet compared to a flying parakeet.

Calculate the extra volume of oxygen used in litres per gram per hour when flying compared to the volume used at rest. Show your working.

_........ litres per gram per hour

Like humans, parakeets need to keep their body temperature constant. Suggest how the volume of oxygen used by a parakeet at rest would change if it was moved to a colder environment.