STAAR Reporting Category 4

Organisms & environment

Middle School Science

Science STAARTAKS Need to Know

All living things are made up of cells.

Unicellular (Single-celled)- organisms that are made up of only one cell.

Multicellular- organisms made up of many cells. (Some have billions & trillions of cells!)

Teacher Domain

http://www.teachersdomain.org/resource/tdc02.sci.life.stru.singlecell/

Cells Most basic part of a living system

“Cells are Building Blocks”

Cells contain organelles Animal & Plant cells both contain:

nucleus- command center of the cell cell membrane- protective outer layer cytoplasm- gelatin-like substance that fills inside of cell

(contains other organelles that are vital to the processes of life)

mitochondria- to provide power for cell activities

Only plant cells have cell walls for support & chloroplasts to carry out photosynthesis.

Animal Cell

Plant Cell

Contain 2 organelles that animal cells do not have:

*Chloroplasts- use sunlight & CO2 to create food for the plant’s cells

*Cell wall- rigid structure that provides protection and support for plant cell

Three Tab Venn Diagram

Animal Cell Plant Cell

Both

Systems work together to carry out various life functions.

Example:

A track runner has different systems that work together:

-Muscles move the arms & legs. This uses up oxygen, which must be provided through the bloodstream.

-The heart starts beating faster to move more blood to the muscle cells that need oxygen.

-As breathing rate increases, the lungs have to take in oxygen & get rid of carbon dioxide more quickly.

-The brain sends signals to the lungs, heart, & muscles to coordinate all these activities.

Levels of Organization

Feedback mechanism

A response of an organism to a given change, such as temperature or the amount of light.

Example: Sweating

If the body temperature gets too high, sweat glands open up, causing a person to sweat.

The sweat then evaporates, carrying heat energy away from the body. This cools the skin.

When the body temperature returns to normal, another nerve signal is sent out to close the sweat glands.

Cells, Tissues, Organs, Organ Systems

When you breathe, cells in your lungs help move oxygen into your bloodstream. Many of these cells together form an air sac, which is a kind of lung tissue. These & other tissues together form a lung, which is an organ. The mouth, nose, & trachea are other organs that work together with the lungs to help you breathe. These are some of the organs that make up the respiratory system. The respiratory system is just one of the many organ systems in the whole human organism.

Systems in the Human BodyThe human body includes systems such as:

CirculatoryRespiratoryDigestiveExcretoryMuscularSkeletalNervous

Circulatory system Arteries are tubes that

carry blood away from the heart

Veins are tubes that return blood to the heart

Capillaries connect arteries and veins. They are tiny tubes that exchange food, oxygen and wastes between blood and body cells.

Respiratory BREATH IN -- your body gets oxygen from the air. Rib muscles

contract to pull ribs up and out. The DIAPHRAGM muscle contracts to pull down the lungs. Tissue expands to suck in air.

BREATH OUT -- you get rid of other gases that your body does not need. Rib muscles relax. The Diaphragm muscle relaxes. Tissue returns to resting position and forces air out.

Digestive system

Breaks down and absorbs food to provide energy for the body

ExcretoryGets rid of body wastes

and excess fluids

Muscles

Muscle contracts to move bones and body parts

Muscles look either striated or smooth: Striated muscle has stripes or

striations in it.

Smooth muscle does not.

Voluntary or Involuntary Muscles

Voluntary muscles are muscles that you can move whenever you want to.

Involuntary muscles contract and relax automatically inside your body. We can not control our involuntary muscles

Did you know?????

There are more than 600 muscles in your body

That nearly 35-40% of your body mass is muscle

The smallest bones are in your ear. The largest bone, the femur, is found in your thigh

Skeletal system

Function of bones protect internal organs support the body make blood cells store minerals provide for muscle

attachment

Joints

A point where one bone attaches to another bone.

There are two different types of joints in the body:

Movable joints (like ball-and-socket, hinge, gliding and pivot joints)

Immovable joints (like the bones of the skull and pelvis) which allow little or no movement

Integumentary System skin is the largest organ in

the body Two distinct layers occur

in the skin: the dermis and epidermis.

The integumentary system has multiple roles in homeostasis, including protection, temperature regulation, sensory reception, biochemical synthesis, and absorption.

Nervous system

collects, transfers and processes information with brain, spinal cord, peripheral nerves, and nerves

Systems A group of parts that form a complex

whole- work together to achieve goals that the parts could not reach alone.

Parts can interact, be related to one another, or depend on each other.

Example:

Circulatory and Respiratory systems work together

Pocket Book Foldable

Systems with Functions

HomeostasisThe body has ways of adjusting to different conditions. Keeping conditions such as body temperature constant is called equilibrium or homeostasis. Equilibrium occurs when a system is balanced.

AdaptationsWhat if a change is too extreme & an organism can’t maintain equilibrium? The organism may die!!

However, most organisms are adapted to the environments where they live. Their body systems & behaviors adjust or change to allow them to survive in the new environment.

Extinction

The loss of an entire species is called extinction.

Example:

If an organism doesn’t have adaptations that allow it to live in a colder climate, then it must move to a warmer environment or it will die. This can affect single organisms as well as whole populations.

Genetic traits

Genes- a segment of DNA on a chromosome that contains information for specific genetic traits. Genes are passed from parents to offspring.

Genetic trait- a characteristic passed on from a parent to offspring.

Genetic traits that help organisms to survive in their environment are called adaptations. Adaptations can be either physical characteristics or behaviors.

Reasons for Adaptation

How are genes passed from parents to offspring?

During reproduction, the parents’ genes in the sex cells (egg & sperm) will create the new organism. This is called sexual reproduction.

In sexual reproduction, both parents pass the genes for traits on to their offspring. Half the genes come from the male and half come from the female.

Sexual reproduction results in genetic diversity due to the large number of gene combinations that may occur.

Dichotomous Keys

A dichotomous key is a tool that helps identify organisms. A dichotomous key consists of several pairs of statements. Based on observations about an organism, the user begins by choosing a statement from the first pair. Each statement leads either to the name of an organism or to another pair of statements. By working through several pairs, you can identify an organism.

Dichotomous Keys 1. a. Edge of wings black-Go to 2. b. Edge of wings not black-Go to 3.

2.

a. Upper wing with black veins-Danaus plexippus

b. Upper wing without black veins-Danaus gillippus

3.

c. Wings blue with white edges-Cupido comyntas

d. Wings black with white edges-Phocides palemon

Classification

Autotroph: An organism that produces its own food. EX: Plants, Algae, Archaebacteria, Phytoplanktons

Heterotroph: An organism that feeds on other organisms. EX: Animals, Protista, Fungi, Bacteria

Classification

Domain: Kingdom Phylum Class Order Family Genus Species

Classification

Classification

The living things are grouped in to three domains which are Archae (primitive, unicellular, prokaryotic, some autotrophs & some heterotrophs, some live in harsh conditions); Bacteria (unicellular prokaryotes, most are heterotrophs, typical bacteria); & Eukarya

Ecosystem – includes the living & nonliving parts of an environment.

Nonliving- water, soil, light, air

Living- plants, animals & other living organisms (makes up the community)

Community – a group of different types or populations or plants, animals, & other organisms living & interacting with one another in an environment.

Each population in a community lives in a particular part of that environment called a habitat.

A habitat is the specific place in which an organism makes its home. As you move up the diagram,

each level is more complex.

Each part of the community has its own function, but together they form the entire pond ecosystem.

Organisms are connected by the energy that flows through the pond community. Both plants & animals require energy.

This flow begins with the plants using energy from the sun and continues through all the organisms in an ecosystem.

Plants change radiant energy from the sun into chemical energy.

Carbon dioxide and water are converted into sugar and oxygen.(Sugar is very important in an ecosystem- it’s food for plants & for other organisms. When plants are eaten, the energy in the plant matter is passed on to other organisms in the food chain.)

Radiant Energy Chemical Energy

TEK 7.5 A recognize that radiant energy from the Sun is transformed into chemical

energy through the process of photosynthesis

Photosynthesis http://www.teachersdomain.org/asset/

tdc02_vid_photosynth/ http://vimeo.com/1616717

Chemical energy passes from plants to animals through a food chain

Producers- (plants) organisms that make their own food

Primary consumers- animals that get their energy from eating plants

Secondary (second-order) consumers- animals that eat primary consumer animals.

Animals can be both a primary & secondary consumer.

Types of consumers

Herbivores- animals that eat only plants

Carnivores- animals that eat only other animals

Omnivores- animals that eat both plants & other animals

Decomposers

Organisms that feed on dead plants & animals. This releases the chemical energy and nutrients in the dead plants and animals back into the environment.

Decomposers play an important role in recycling nutrients & energy.

Food Chain- shows the flow of energy from one organism to another to yet another.

Food Web A complex system of energy flow through overlapping food chains.

Energy passes in many different directions through all the organisms.

Food Web Lab Activity

Succession

Succession can happen in any environment where change occurs.

Other examples: a plowed farm field, a burned forest, or a grassland that gradually receives less rainfall.

Rebuilding of populations in a community or ecosystem that has been changed.

Succession

Primary Succession: It can take place on a newly formed volcanic island or in an area newly exposed by a melting glacier.

Pioneer species in primary succession are Lichens & Mosses

Secondary Succesion: It takes place where organisms already live or it takes place after an existing ecosystem has been disturbed.

Ecological Succession

http://www.youtube.com/watch?v=AWwe0udewD8

http://www.youtube.com/watch?v=dhYArqKVF9Q&feature=related