Life Science
Natural Selection
Sometimes the differences in characteristics between individuals of the same species provide advantages in surviving, finding mates, and reproducing.
Variation of Inherited Traits
Different organisms vary in how they look and function because they have different inherited information.
Animal Structure and Function
Plants and animals have both internal and external structures that serve various functions in growth, survival, behavior, and reproduction.
Food Webs
The food of almost any kind of animal can be traced back to plants. Organisms are related in food webs in which some animals eat plants for food and other animals eat the animals that eat plants. Some organisms, such as fungi and bacteria, break down dead organisms (both plants or plants parts and animals) and therefore operate as “decomposers.” Decomposition eventually restores (recycles) some materials back to the soil.
Species Extinction
Some kinds of plants and animals that once lived on Earth are no longer found anywhere.
Information Processing
Different sense receptors are specialized for particular kinds of information, which may be then processed by the animal’s brain. Animals are able to use their perceptions and memories to guide their actions.
Food and Animal Needs
Food provides animals with the materials they need for body repair and growth and the energy they need to maintain body warmth and for motion.
Organism Traits and Inheritance
Many characteristics of organisms are inherited from their parents.
Plant Structure and Function
Plants and animals have both internal and external structures that serve various functions in growth, survival, behavior, and reproduction.
Adaptation
For any particular environment, some kinds of organisms survive well, some survive less well, and some cannot survive at all.
Adapt Island!
Variation of Traits due to Environmental Factors
The environment also affects the traits that an organism develops.
Growth and Development of Organisms
Reproduction is essential to the continued existence of every kind of organism. Plants and animals have unique and diverse life cycles.
Fossil Evidence
Fossils provide evidence about the types of organisms that lived long ago and also about the nature of their environments.
Ecosystem Stability
Organisms can survive only in environments in which their particular needs are met. A healthy ecosystem is one in which multiple species of different types are each able to meet their needs in a relatively stable web of life. Newly introduced species can damage the balance of an ecosystem.
Invasive Frogs
Biodiversity and Humans
Populations live in a variety of habitats, and change in those habitats affects the organisms living there.
Ecosystem Dynamics, Functioning, and Resilience
When the environment changes in ways that affect a place’s physical characteristics, temperature, or availability of resources, some organisms survive and reproduce, others move to new locations, yet others move into the transformed environment, and some die.
Cycles of Matter and Energy Transfer in Ecosystems
Matter cycles between the air and soil and among plants, animals, and microbes as these organisms live and die. Organisms obtain gases, and water, from the environment, and release waste matter (gas, liquid, or solid) back into the environment.
Biosphere Architect
Social Interactions and Group Behavior
Being part of a group helps animals obtain food, defend themselves, and cope with changes. Groups may serve different functions and vary dramatically in size.
Animal Group
Organism Traits and Environment
Other characteristics result from individuals’ interactions with the environment, which can range from diet to learning. Many characteristics involve both inheritance and environment.
Plant Growth
Plants acquire their material for growth chiefly from air and water.