Science Lesson 4 Flashcards
organism
living thing that can carry out life processes by itself
Organisms made up of just one cell that perform all of the functions necessary for life
unicellular organism
Do unicellular organisms have different levels of organization?
no
What are the advantages of being unicellular organism?
need fewer resources and can live in harsh conditions *(eg. hot springs & very salty water)
What is the disadvantage to being a unicellular organism?
the entire organism dies if the one cell dies
What are the different levels of organization that multiccellular organisms are grouped into?
tissues
organs
organ systems
How do multicellular organisms reproduce?
sexual reproduction–>single cell that then divides
Describe some characteristics of multicellular organisms.
larger size
longer life span
can survive even if one cell dies
Disadvantages of being multicellular?
- need more resources than unicellular org
- cells are specialized for certain jobs so they must depend on each other to perform all of the functions
Tissues
a group of similar cells that perform a common function
What are the four basic types of tissue?
nervous
epithelial
connective
muscle
This tissue type functions as a messaging system within the body
Nervous tissue
This tissue is protective and forms boundaries, such as skin
Epithelial tissue
This type of tissue holds parts of the body together and provides support and nourishment to organs (eg. bones & blood)
Connective tissue
this type of tissue helps produce movement
muscle tissue
A structure made up of a collection of tissues that carries out a specialized function
organ
group of organs that work together to perform body functions
organ system
Give examples of organ systems
circulatory system
digestive system
the arrangement of parts in an organism or an object
structure
the structure of a cell, tissues, or organ determines the ________________.
function
the activity of each part in an organisim
function
the lungs are made up of millions of tiny air sacs called ______________
alveoli
How does the structure of the alveoli relate to the function in lungs?
large number of alveoli increases the surface area of the lungs to let enough oxygen and CO2 move b/w the lungs and the blood
What do all complex organisms need to survive?
receive nutrients
exchange CO2 & oxygen
have waste products taken away
This system delivers nutrients to the body cells and carries away wastes
circulatory system
This system carries oxygen to cell and removes carbon dioxide
circulatory system
This system in most animals breaks down food mechanically & chemicallly
Digestive system
Taking on oxygen is a function of which system
Respiratory system
Explain how the digestive, nervous and respiratory systems are related.
The digestive system breaks down nutrients and it enters into the circulatory system. The circulatory system also takes oxygen from the lungs after the respiratory system exchanges the oxygen. The circulatory system carries the oxygen to other organs
Describe how waste is taken care of by the body.
Sweat evaporates from the skin.
Solid wastes and some water move out as part of the digestive system
CO2 & some water are breathed out through the respiratory system
In humans, largest amount of excess water & wastes are carried by the blood to the kidneys where wastes are filtered out of the blood through tubules in the kidneys and excreted as urine.
