Which hypothesis for the abiotic formation of organic molecules suggests that early Earth's atmosphere was a neutral atmosphere?

Amino acids were found near volcanic eruption sites.
The energy for this synthesis could have come from lightning and UV radiation.
Some evidence suggests that the early atmosphere was made up primarily of nitrogen and carbon dioxide.
Organic compounds were first produced in deep-sea hydrothermal vents.

Some evidence suggests that the early atmosphere was made up primarily of nitrogen and carbon dioxide.

If the half-life of carbon-14 is about 5,730 years, then a fossil that has 1/16 of the normal proportion of carbon-14 to carbon-12 should be about how many years old?

11,200
2,800
16,800
22,900

22,900

What is thought to be the correct sequence of these events, from earliest to most recent, in the evolution of life on Earth?
1. origin of mitochondria
2. origin of multicellular eukaryotes
3. origin of chloroplasts
4. origin of cyanobacteria
5. origin of fungal-plant symbioses

4, 1, 3, 2, 5
4, 3, 2, 1, 5
4, 1, 2, 3, 5
4, 3, 1, 5, 2

4, 1, 3, 2, 5 (A)

An early consequence of the release of oxygen gas by plant and bacterial photosynthesis was to _____.

cause iron in ocean water and terrestrial rocks to rust (oxidize)
change the atmosphere from oxidizing to reducing
make it easier to maintain reduced molecules
prevent the formation of an ozone layer

cause iron in ocean water and terrestrial rocks to rust (oxidize)

What is true of the Cambrian explosion?

Only the fossils of microorganisms are found in geological strata older than the Cambrian explosion.
There are fossils of animals in geological strata that are older than the Cambrian explosion.
The Cambrian explosion is evidence for the instantaneous creation of life on Earth.
The Cambrian explosion marks the appearance of filter-feeding animals in the fossil record.

There are fossils of animals in geological strata that are older than the Cambrian explosion.

Which of the following characteristics are expected in the first animals to have colonized land?

I) They were probably herbivores (ate photosynthesizers).
II) Animals had four appendages.
III) Animals had the ability to resist dehydration.
IV) Animals had lobe-finned fishes as ancestors.
V) Invertebrates

I, III and V
I, II, III and IV
III and V
III only

I, III and V

Hox genes are thought to play an important role in the development of different morphologies because _____.

they provide positional information in the embryo
they paved the way for the development of multicellular organisms
they affect the timing of reproductive development in the organism
they affect the order of genes on certain chromosomes
they affect the timing of development in the embryo

they provide positional information in the embryo

The duplication of homeotic (Hox) genes has been significant in the evolution of animals because it _____.

allowed animals to survive on significantly fewer calories
caused the extinction of major groups
reduced morphological diversity into simpler forms of life
permitted the evolution of novel forms

permitted the evolution of novel forms

A swim bladder is a gas-filled sac that helps fish maintain buoyancy. The evolution of the swim bladder from lungs of an ancestral fish is an example of _____.

adaptive radiation
exaptation
paedomorphosis
changes in Hox gene expression

exaptation

If one organ is an exaptation of another organ, then these two organs _____.

are found in the same species
are undergoing convergent evolution
are homologous
have the same function

are homologous

Adaptive radiations can be a direct consequence of four of the following five factors. Select the exception.

an adaptive radiation in a group of organisms (such as plants) that another group uses as food
evolutionary innovation
vacant ecological niches
colonization of an isolated region that contains suitable habitat and few competitor species
genetic drift

genetic drift