Download Case 21 Assessment for Living Organisms and Genetics

Case 21 Assessment for Living Organisms and Genetics
Items 4, 9, 10, 18, 26, and 32 include questions related to single-celled (unicellular) organisms or
comparisons between plant and animals cells.
Essential Standard 5.L.1 reads, “Understand how structures and systems of organisms (to include the
human body) perform functions necessary for life.”
Clarifying Objective 5.L.1.1reads, “ Explain why some organisms are capable of surviving as a single cell
while others require many cells that are specialized to survive.”
Unpacked Content for 5.L.1.1 states, “Students know that unicellular organisms consist of a single cell
and perform all life processes within a single cell. Students know that multicellular organisms are
organisms that consist of more than one cell and have differentiated cells that perform specialized
functions in the organism. Students know that many organisms –including humans- are multicellular.
Students know that in complex multicellular organisms, only the surface cells that are in contact with
the external environment are able to exchange substances with it. Cells within the organism are too far
away from the environment for direct exchange. This is the reason multicellular organisms have
developed transport systems.”
Based on the Unpacked Content, students should have an awareness that some organisms exist as a
single cell, however, study is directed to multicellular organisms, namely the human body.
Consider the following assessment example provided by DPI:
5.L.1.1 Sam is studying a sample of lake water using a microscope. He finds an organism moving
around in the water and he thinks it might be a multicelled organism. Which of the following
characteristics of the organism make it MOST likely to be a multicelled organism?
a. moving body parts
b. a beating heart
c. what appears to be a body covering
d. hair-like structures on its surface
The best answer is choice B.
The concept of cells is introductory in 5th grade. Upper elementary students are just beginning to learn
about cells as the basic unit of structure. Middle school students will expand their knowledge about cells
to include materials made by cells and materials that are inside of cells. They also recognize that
structures such as tissues and organs are part of a hierarchy traced back to the cell.
Looking ahead to 7th grade Essential Standards will help add clarity to 5th grade expectations as well as
assessment parameters:
Essential Standard 7.L.1 reads, “Understand the processes, structures and functions of living
organisms that enable them to survive, reproduce, and carry out the basic functions of life.”
WCPSS Elementary Science – November 2012
Clarifying Objective 7.L.1.1 reads, “Compare the structures and life functions of single-celled organisms
that carry out all the basic functions of life including:
Euglena
Amoeba
Paramecium
Volvox”
7.L.1.1 Unpacked Content states, “Within cells, many of the basic functions of organisms – such as
extracting energy from food, getting rid of waste, movement and secreting waste- are carried out. The
way in which cells function is similar in all living organisms. Even the simplest organisms have parts
which enable them to move, take in food, reproduce and to detect the environment they are in. Euglena
- moves by a flagellum, known for a unique feature – an eye spot, some contain chlorophyll and are
common in fresh water. The amoeba moves by cytoplasmic streaming, surrounds food, and engulfs it
using pseudopds. Paramecium is the most complex and specialized of the protists. It moves by cilia.
Volvox is a colony of ciliates, some containing chlorophyll.”
While Clarifying Objective 7.L.1.2 reads, “Compare the structures and functions of plant and animal cells,
including major organelles (cell membrane, cell wall, nucleus, chloroplasts, mitochondria, and
vacuoles).”
Unpacked Content for 7.L.1.2 states, “ All living things are composed of cells, from just one to many
millions, whose details usually are visible only through a microscope. A cell is the smallest part of any
living thing. There are many parts of a cell. Each part of a cell completes a certain function for the cell.
These parts are found in plant and animal cells:
Cell membrane – forms the outer boundary of the cell and allows only certain materials to move
into or out of the cell
Cytoplasm – a gel-like material inside the cell; it contains water and nutrients for the cell
Nucleus – directs the activity of a cell; it contains chromosomes with the DNA
Nuclear membrane – separates the nucleus from the cytoplasm
Mitochondria – break down food and release energy to the cell
Vacuoles – are storage areas for the cell
Some organelles are found only in plant cells. These organelles are:
Cell wall – provides structure to the plant cell
Chloroplasts – contain chlorophyll that makes food for the plant cell”
After reviewing 5th grade and 7th grade Essential Standards, Clarifying Objectives, and Unpacked
Content, it is not necessary for 5th grade students to identify single-celled (unicellular) organisms,
compare plant and animal cells, or identify and describe the functions of organelles present in cells.
WCPSS Elementary Science – November 2012
While reviewing data from the 5th grade Living Organisms and Genetics Assessment prepared by Case
21, the Elementary Science Department recommends disregarding items 4, 9, 10, 18, 26, and 32.
WCPSS Elementary Science – November 2012