Grade 10 Term 2 Criterion A : Hormones and Homeostasis and Ecology

Ecology

the study of interactions between organisms and their environment

Organism

A single living thing

Population

A group of organisms of the same species living in the same area at the same time.

Community

A group of populations living and interacting with each other in an area

Ecosystem

A community and its abiotic environment

Biome

Large regions with similar climate, soil, and life forms.

Biosphere

The sum of all ecosystems on Earth.

What does ecology helps us understand

how different organisms interact and depend on each other.

Biotic Factors

living components of an ecosystem

Abiotic Factors

non-living components of an ecosystem

Energy Flow

the transfer of energy through trophic levels in a food chain or food web.

Producers

Organisms that produce their own energy (plants)

Consumers

Organisms that obtain energy by eating other organisms

Primary Consumers

Obtain energy by eating producers (Herbivores)

Secondary Consumers

Obtain energy by eating other animals (Carnivores)

Tertiary Consumers

Obtain energy by eating secondary consumers

Decomposers

Organisms that obtain energy from waste products (feces, dead bodies) of other organisms (Funghi, Bacteria)

Detritivores

eat dead things (Earth worms)

Nutrient cycling

the movement and recycling of essential nutrients (such as carbon) in ecosystems.

Why is energy transfer inefficent?

the amount of energy transferred, decreases for each trophic level.

True or False : Their are more producers than consumers

True

How is energy lost

• heat

• excretion

• not being digested

Autotrophy

Organisms that produce their own food from organic molecules (photoautrphy/chemoautotrophy)

Heterotrophy

Organisms that derive energy from other living organisms

Saprotrophs

Absorb dead things by excreting enzymes.

Ecological Productivity

Rate of generation of biomass in an ecosystem

Biomass

Mass of tissue

Eutrophication

the process in which a water body becomes overly enriched with nutrients, leading to the plentiful growth of simple plant life.

Percentage Increase Formula

Homeostasis

maintaining an constant optimum internal temperature for cells to function.

What is the role of sensory receptors

constantly feed the brain information about conditions around the body.

Negative Feedback

A change sets off a response that cancels out the change.

Hypothalamus

Temperature control center

Convection

Transfer of heat to and from the body

Radiation

Transfer of heat in the form of rays

Conduction

Transfer of heat by direct contact with another object

To cool down you….

Sweat

To warm up you…

Shiver or body hair stands up

Inslulin

released when blood sugar is too high, stimulates the removal of glucose from blood

Glucagon

released when blood sugar is too low, stimulates the release of glucose into the blood.

Glucose

Simple sugar

Glycogen

storage form of carbohydrates

Which hormone turn glycogen into glucose

Glucagon

Where do Endocrine glands secrete hormones

Into the blood stream

As the level of hormone in the blood stream rises ….

The production of that hormone is switched off

Hormone

chemical messenger that travels via the blood stream

Endocrine system message speed + duration of effect

messages are slow but the length of the effect is long (until hormone is broken down)

Nervous system message speed + duration of effect

messages are very fast (milliseconds) but the length of the effect is short (until the nerve impulse stops)