Which gas was least abundant in Earth's early atmosphere, prior to 2 billion years ago?
We are living during the _________ era.
Which of the following is the correct sequence of these events in the origin of life?
I. formation of protocells
II. synthesis of organic monomers
III. synthesis of organic polymers
IV. formation of DNA-based genetic systems
A) III, II, I, IV
B) I, II, III, IV
C) IV, III, I, II
D) II, III, I, IV
E) I, III, II, IV
If the half-life of carbon-14 is about 5,700 years, then a fossil that has one-sixteenth of the carbon-14 to carbon-12 should be about how many years old?
The scientific discipline concerned with naming organisms is called:
Know the order of the taxonomic levels:
Kingdom, Phylum, Class, Order, Family, Genus, Species
Organisms A, B, and C belong to the same class but to different orders. Organisms D, E, and F belong to the same order bu to different families. Which of the following pairs of organisms would be expected to show the greatest degree of structural homology?
A) D and F
B) C and F
C) A and C
D) B and D
E) A and B
If humans and pandas belong to the same class, then they must also belong to the same:
Which of the following pairs are the best examples of homologous structures?
A) bat forelimb and bird wing
B) bat wing and human arm
C) owl wing and hornet wing
D) porcupine quill and cactus spine
E) Australian mole and North American mole
The ostrich and the emu look very similar and live in similar habitats, however they are not very closely related. This is an example of:
A) divergent evolution
C) sympatric speciation
D) convergent evolution
E) adaptive radiation
Which statement represents the best explanation for the observation that the nuclear DNA of wolves and domestic dogs has a very high degree of identity?
A) dogs and wolves shared a common ancestor very recently
B) dogs and wolves are both members of the family Canidae
C) dogs and wolves belong to the same order
D) dogs and wolves have very similar morphologies
E) convergent evolution has occurred.
If you were using cladistics to build a phylogenetic tree of cats, which of the following would be the best outgroup?
C) domestic cat
Based on this tree, which of the following statements is not correct?
A) Salamanders are a sister group to the group containing lizards goats, and humans
B) the group highlighted by shading is paraphyletic
C) lizards are more closely related to salamanders than lizards are to humans.
D) The lineage to salamanders was the first to diverge from the other lineages.
The animals and plants of India show large differences from species in nearby Southeast Asia. Why might this be true?
India was a separate continent until relatively recently
Which of these is the most common compound in the cell walls of gram-positive bacteria?
Prokaryotes are classified into:
Kingdom Bacteria and Kingdom Archaea
Penicillin is an antibiotic that inhibits enzymes from catalyzing the synthesis of peptidoglycan, so which prokaryotes should be most vulnerable to inhibition by penicillin?
B) gram-positive bacteria
C) endospore-bearing bacteria