Unit 1
define scientific theory
an explanation for observable phenomena
What are the basic structural units of all living organisms
cells
define gene
a section of DNA that affects traits
define evolution
the change in heritable traits that occurs in populations over time.
Physical traits that increase an organism’s fitness are called _[blank]_.
physical adaptations
describe a similarity between scientific laws and scientific theories
Both can change in light of new evidence
define cell theory
a theory that describes cells and how they operate
Long strands of _[blank 1]_ that contain _[blank 2]_ are found within _[blank 3]_ .
blank 1- DNA
blank 2- genes
blank 3- chromosomes
Where does natural selection occur?
in areas that are close to human settlements
in natural areas, unaffected by human actions
happens when a plant cannot maintain homeostasis.
Its cells will decrease function, and it will eventually die.
Viktor made a discovery that he wants to share with his class. In his garden, he found that certain layers of material absorb more moisture than others and allow for better plant growth.
To help explain this to his class, Viktor makes a _[blank 1]_ model of the soil layers out of different types of materials, so that the students in his class can examine it and pass it around. He also creates a _[blank 2]_ model that has pictures showing the relationship between layers in the soil and the amount of water absorbed.
blank 1- physical
blank 2- conceptual
Which scientist discovered that new cells only come from existing cells?
Louis Pasteur
define alleles
One of the two copies of genetic code that form a gene.
How are the ages of extinct organisms determined?
by studying the concentration of radioactive atoms in their fossil.
Which functions are involved in maintaining homeostasis in plants?