Population and the Environment Bio 2 By Paulina Bui

Identifying Living Things

Identify the characteristics of life.

•have cells

•use energy

•reproduce

•respond to environment

•grow and develop

Check the items that are living.

•a horse

•a mushroom

•bacteria

Environmental Factors

•Biotic- of or relating to an environmental factor that is living or came from something that was once living

•Abiotic- of or relating to an environmental factor that is not living and has never lived

Ecosystems

•Ecosystem- all the biotic and abiotic factors in a particular area

Biotic factors in a forest ecosystem:

•Plants

•Animals

•Bacteria

•Fungi

•Dead or decaying organisms

Abiotic factors in a forest ecosystem:

•Rocks

•Dirt

•Water

•Fire

•Climate

Habitat and Niche

•A habitat is an organism's physical environment.

•A niche is the role an organism plays in the environment in which it lives.

Habitat and Niche

Habitat determines niche.

•An organism's adaptions to its habitat determine its niche.

1. Adaptation- an inherited trait that increases an organism survival in its environment

•A change in habitat can result in a change in niche.

•Competitive exclusion principle states that two species cannot occupy the same niche in the same habitat.

Identifying an Organism's Niche

•An organism's niche is determined by its habitat, which is its physical environment.

•Adaptation, inherited traits that increase an organism's chance of survival, also determine an organism niche.

Real World Connection: Observation and Interference

Observation

•Recognizing and noting with your senses

Inference

•Logical interpretation made from observation

Ways of Interacting

•Interactions with biotic factors

1. Members of their own population

2. Other populations

•Interactions with abiotic factors

1. Climate

2. Water

3. Landscape

•Interactions can be positive, leading to population growth

Positve Interaction

•Favorable climate

•Increase in food source

•Increase in nest sites or shelter

•Decrease in predators

Negative Interaction

•Unfavorable climate

•Decrease in food source

•Increase in predators

•Natural disaster

•Human activitiy

Population Affect Their Environment

They change:

•the size of other populations

•the landscape

•water availability

Interactions Can Be Cyclical

Predator-prey relationships- an interaction between two species that controls the population size of both species

Real World Connection: Human Activities and Populations

Human activity can have a negative effect on populations.

There is debate over the effects of some human activities.

•Damming

•Climate change

•Reintroduction of predators

Identify the following as biotic or abiotic

•Sunlight and heat: abiotic

•Insects: biotic

•Rotting log: biotic

•Bacteria: biotic

•Water: abiotic

•Rocks: abiotic