EduNinjaThe Hawaiian happy-face spider, Theridion grallator, is found on several of the Hawaiian islands. Some of the spiders have a very distinctive pattern on their bodies as shown in Fig. 1.3.
Fig. 1.3
Scientists think that the pattern on the bodies of the spiders is an adaptive feature. Explain the term adaptive feature with reference to this pattern.
Fig. 2.1 shows an Arctic wolf, Canis lupus. These wolves are one of the few mammals adapted to the extreme cold of the tundra in the Canadian Arctic and in Alaska.
Fig. 2.1
Arctic wolves show many adaptive features to a cold environment.
Explain what is meant by the term adaptive feature.
Mangrove trees are hydrophytes because they grow in water.
Fig. 2.1 shows a young mangrove tree.
Fig. 2.1
An adaptive feature is a feature that increases the fitness of an organism.
Define the term fitness.
Mangrove trees have many aerial roots and floating seeds.
Suggest how these adaptive features allow mangrove trees to survive in water. many aerial roots
floating seeds
Which feature is a leaf adaptation for living in the desert?
large size
many stomata
rolled along its length
thin waxy cuticle
Samphire is a plant that grows in coastal areas. It has adaptations that enable it to live in areas with high salt concentration in the soil and strong winds.
Which adaptations would samphire possess to minimise water loss from root cells by osmosis and leaves by evaporation?
salt concentration
in root cells
leaf surface area
high
high
high
low
low
high
low
low
Cheetahs, Acinonyx jubatus, are carnivores found in the dry grasslands and woodlands of southern Africa. Cheetahs hunt for food during the day. They eat deer and antelope.
The cheetah is the fastest mammal on land but can only run at high speed (sprint) over a short distance. Its hunting strategy is to creep up on prey and then sprint to catch them.
Fig. 3.1 is a photograph of a cheetah in its natural habitat.
Fig. 3.1
Suggest how these adaptive features enable cheetahs to survive in their natural environment. fur colouring
streamlined body shape
Researchers investigated the effect of adding cattle manure (cattle faeces) to fields where snap bean plants, Phaseolus vulgaris, were grown. Cattle manure contains some protein.
Snap bean plants are legumes which have root nodules that contain nitrogen-fixing bacteria.
Fig. 4.1 shows some root nodules.
Fig. 4.1
Suggest the advantage to farmers of having snap bean plants that have a large number of root nodules.
Hydrophytes are plants that show many adaptive features for life in aquatic habitats.
Fig. 4.1 shows several species of hydrophyte growing in freshwater.
Fig. 4.1
A student investigated the density of stomata on the leaves of two different species of freshwater hydrophyte.
Table 4.1 shows the results.
Table 4.1
Suggest reasons for the difference between the results for the two species.
The large air spaces are an adaptation of water lily leaves. Suggest why.
Hydrophytes are adapted to aquatic habitats.
State the name used for plants that are adapted to dry habitats.
Explain what is meant by the term adaptive feature.
Which feature helps a xerophyte survive in its environment?
flat leaves with a large surface area
no cuticle
short roots
sunken stomata
Xerophytes grow in habitats with low rainfall and soils that often have high concentrations of salts. Fig. 4.1 shows the xerophyte Yucca treculeana growing on salt flats.
Fig. 4.1
Explain how xerophytes, such as Y. treculeana, are adapted to absorb sufficient water in the conditions in which they live.
Explain how xerophytes are adapted to reduce water loss to the atmosphere.
Xerophytes often have many defence mechanisms that reduce or prevent herbivores eating them.
Suggest how xerophytes protect themselves against herbivores.