Grade 7 Focus:  Life Science

Cell Biology:

1.     All living organisms are composed of cells, from one to many trillion, whose details are visible only through a microscope. As a basis for understanding this concept, students know:

 

      a.   cells function similarly in all living organisms.

b. cell parts (e.g. cell membrane, cytoplasm, nucleus, mitochondria, endoplasmic   reticullum, ribosomes, vacuole, chloroplasts, cell wall) and their functions

      c.   the characteristics that distinguish plant cells from animal cells.

the nucleus contains the genetic information, chromosomes in plant and animal cells.

d.     mitochondria release energy and chloroplasts capture sunlight for photosynthesis.

e.     cells divide through the process of mitosis, which results in two daughter cells with identical sets of chromosomes,

f.      as multicellular organisms develop, their cells differentiate.

 

Structure and Function in Living Systems

2. The anatomy and physiology of plants and animals illustrate the complementary nature of structure and function. As a basis for understanding this concept, students know:

 

a.     plants and animals have levels of organization for structure and function, including cells, tissues, organs, organ systems, and the whole organism.

b.     organ systems function because of the contributions of individual organs, tissues, and cells. The failure of any part can affect the entire system.

c.     the primary purposes of the human body systems: digestive, respiratory, skeletal, muscular, circulatory, nervous, reproductive, excretory and endocrine.

d.     the structures and processes by which plants reproduce, transport materials, and generate energy through photosynthesis.

 

Diversity of Life

3.   Organisms are classified based on evolutionary characteristics. As a basis for understanding this concept, students know:

 

a.     the seven levels of classification.

b.     the kingdoms and the key characteristics of each kingdom.

c.     that viruses are not classified in any of the kingdoms due to their characteristics.

 

Genetics

4.  A typical cell of any organism contains genetic instructions that specify its traits. As a basis for understanding this concept, students know:

 

a.     the differences between the life cycles and reproduction of sexual and asexual organisms.

b.     meiosis is the process by which sex cells containing half the number of chromosomes are produced.

c.     sexual reproduction produces offspring that inherit half their genes from each parent.

d.     an inherited trait can be determined by one or more genes.

e.     plant and animal cells contain many thousands of different genes, and typically have two copies of every gene. The two copies (or alleles) of the gene may or many not be identical. The alleles may be dominant or recessive, which determines the phenotype and genotype.

f.      DNA is the genetic material of living organisms and is located in the chromosomes of each cell.

 

Evolution

5.  Biological evolution accounts for the diversity of species developed through gradual processes over many generations. As a basis for understanding this concept, students know:

 

a .  both genetic variation and environmental factors are causes of evolution and diversity of organisms.

b.  the reasoning used by Darwin in making his conclusion that natural selection is the mechanism of evolution.

c.  how evidence from geology, fossils, and comparative anatomy provide a basis for the theory of evolution.

d.  how to construct a simple branching diagram to classify living groups of organisms by shared derived characteristics.

e.  extinction of a species occurs when the environment changes and the adaptive characteristics of a species are insufficient for its survival.

 

Earth and Life History

6.  Evidence from rocks allows us to understand the evolution of life on Earth. As the basis for understanding this concept, students know:

 

a.     Earth processes today are similar to those that occurred in the past; and slow geologic processes have large cumulative effects over long periods of time.

b.     the history of life on Earth has been disrupted by major catastrophic events (e.g., major volcanic eruptions, the impact of an asteroid).

c.     the rock cycle includes the formation of new sediment and rocks. Rocks are often found in layers with the oldest generally on the bottom.

d.     evidence from geologic layers and radioactive dating indicate the Earth is approximately 4.6 billion years old and that life has existed for more than 3 billion ears.

e.     fossils provide evidence of how life and environmental conditions have changed over time.

f.      how movements of the EarthÕs continental and oceanic plates through time have affected the past and present distribution of organisms.

g.     how to explain significant developments and extinctions of plant and animal life on the geologic time scale.

 

Physical Principles in Living Systems

7.  Physical principles underlie biological structures and functions. As a basis for understanding this concept, students know:

 

a.     visible light is a small band within a very broad electromagnetic spectrum.

b.     for an object to be seen, light reflected from it must enter the eye.

c.     light travels in straight lines except when the medium it travels through changes (e.g., light traveling through air, water, and glass)/..

d.     how simple lenses are used in a magnifying glass, the eye, camera, telescope and microscope.

e.     white light is a mixture of many wavelengths (colors) and tat retinal cells react differently to various wavelengths.

f.      light interacts with matter by transmission, absorption, or scattering. Matter may be transparent, translucent, or opaque.

g.     the angle of reflection of a light beam is equal to the angle of incidence.

h.     the properties of sound waves (e.g., frequency, pitch)

i.      how the ear processes sound waves and transmits that information to the brain.

 

Scientific Method: Investigation and Experimentation

8.  Scientific progress is made by asking meaningful questions and conducting careful investigations.  As a basis for understanding this concept, students should develop their own questions and perform investigations. Students will:

 

a.     make observations, develop a testable question and form a hypothesis.

b.     develop and conduct a controlled experiment with a single independent variable.

c.     select and use appropriate tools and technology (e.g., balances, spring scales, microscopes, binoculars, calculators and computers) to perform tests.

d.     collect and record data using the metric system

e.     communicate the logical connection among science concepts, hypothesis, tests conducted, data collected, and conclusions drawn from the scientific evidence.

f.      construct scale models, maps and appropriately labeled diagrams to communicate scientific knowledge (e.g., motion of EarthÕs plates, cell structure)

g.     communicate the steps and results from an investigation in written reports and verbal presentations.

h.     utilize a variety of print and electronic resources (e.g., the World Wide Web) to collect information as evidence as part of a research project.