A
What is a Gene?
a. a type of protein
b. a segment of DNA on a chromosome
c. a whole chromosome
d. a nitrogen base
b. a segment of DNA on a chromosome
DNA has a shape best described as a:
a. single strand
b. ladder
c. double helix
d. circle
c. double helix
which of the following is not a component of a nucleotide?
a. nitrogen base
b. sugar
c. phosphate group
d. amino acid
d. amino acid
how many nitrogen bases are found in DNA?
a. 2
b. 3
c. 4
d. 5
what are fossils?
a. remains of living organisms
b. remains or evidence of once-living organisms
c. rock formations created by water erosion
d. mineral deposits found in caves
b. remains or evidence of once-living organisms
which of the following is not a type of fossil formation?
a. mineralization
b. crystallization
c. carbonization
d. molds and casts
b. crystallization
variations are:
a. differences among individuals of a species
b. identical traits
c. learned behaviors
d. environmental changes
a. differences among individuals of a species
Darwin made key observations on the:
a. Hawaiian islands
b. Galapagos islands
c. Caribbean islands
d. Madagascar
b. Galapagos islands
in the process of mineralization, what happens to the original tissue of the organism?
a. it is completely preserved in its original form
b. it is replaced by rock-forming minerals
c. it is compressed into a thin carbon film
d. it is dissolved, leaving only an impression
b. it is replaced by rock-forming minerals
DNA contains instructions for making:
a. lipids
b. carbohydrates
c. proteins
d. vitamins
c. proteins
which nitrogen base pairs with adenine?
Thymine
the process of copying DNA is called:
Replication
which type of RNA carries the genetic code from DNA to ribosome?
mRNA
which type of fossil provides evidence of an organism's activity rather than its body?
trace fossils
in undisturbed rock formations, how are the rock layers arranged according to age?
bottom layers are the oldest, top layers are youngest
transcription occurs in the:
how many nitrogen bases are needed to form a codon?
3
artificial selection differs from natural selection because:
humans perform the selection
what is the term that describes blending with surroundings?
camouflage
what is mass extinction?
when many species become extinct within a few million years or less
what is the difference between relative-age dating and absolute-age dating?
absolute-age dating determines a rock's age in years, while relative-age dating determines order
mutations in which cells can be inherited?
sperm or egg cells
Recombinant DNA is made by:
inserting DNA from one organism into another
what are transitional fossils?
a fossil that has characteristics of both ancestral organisms and organisms that evolved later
name a sudden environmental change that could cause extinction
volcano, meteorite..