B3 Life on Earth Lesson 1: Species and Adaptation
Objectives • MUSTexplain how species are adapted to their environments and give examples • SHOULD explain that species compete for resources • COULD predict the effect on species of disturbance to a food web
Key Words • You need to be able to define the following: • Adaptation • Species • Habitat • Competition • Food web • Interdependence
Textbook Answers 1) A group of organisms that can breed together to produce fertile offspring. 2) It has gills for gaseous exchange; these can exchange gases across their surface underwater; it has fins to keep it upright when swimming; it has a mouth position that suits its way of feeding; a swim bladder that allows it to maintain a variety of depths in the water. 3) Space (particularly space in the light spots where there is a gap in the canopy above); light; nutrients (the competition for nutrients would be between their root systems).
Textbook Answers 4) There might be more heather for the sheep and rabbits to feed on, but the populations of shrews and lizards would decrease. The population of insect-eating birds would decrease because their food source has gone; the population of owls and merlins might also be impacted because one of their groups of prey species (the insect-eating birds) was depleted. 6) The way that all the species in the habitat depend on one another for survival; if the number of one species dropped or increased rapidly, this would have a knock-on effect on all other species in the food web (with examples).
Worksheet Answers Activity 1 (Low demand) • Polar bear: In order – cold, thick fur, insulate, blubber, black, snow, claws, nostrils • Water lily: In order – supported, surface, waxy cuticle, absorb sunlight, wind, water movement,