Explanations
1. A
All monerans are prokaryotes. Bacteria commonly have
cell walls, but so do other organisms, such as in kingdoms Fungi
and Plantae. Radial cleavage is a characteristic found in kingdom
Animalia, and angiosperms and gymnosperms are distinctions within
the Plantae kingdom.
2. A
Autotrophic (“self-feeding”) organisms produce their
own organic nutrients, using energy from sunlight (photosynthesis)
or chemical energy (chemosynthesis). Heterotrophic (“other-feeding”)
organisms must consume the organic nutrients in other living organisms.
Fungi are heterotrophic organisms.
3. B
Fungi have chitinous cell walls. Spiders are arthropods,
which have chitin incorporated into the exoskeleton. Like all animals,
however, the cells of spiders do not have cell walls. The euglena
and cnidarian do not possess cell walls. Protist molds and bryophytes
both have cell walls made of cellulose.
4. A
Taxonomists use body symmetry (e.g., bilateral vs.
radial), patterns of embryonic development (e.g., spiral vs. radial
cleavage), similarity of molecular clocks (e.g., cytochrome c), and
complexity of tissue organization (particularly development of sensory
organs and nervous tissue). Motility is characteristic of organisms
in various kingdoms and is not used to determine evolutionary relationships
among animals.
5. E
Bryophytes reproduce using single-celled spores rather
than seeds. Spores require a flagellated male gamete to travel through
water for fertilization. Seeds contain both a complete embryo and
a food supply, allowing the embryo to grow independently of outside
food sources when it is smallest and most vulnerable. Also, the
male gamete of seed plants is pollen, which can travel through the
air. The vascular system has allowed plants to grow larger and develop
different parts with specialized functions. Flowers and fruits increase
the efficiency of reproduction by recruiting animals into pollen
and seed distribution. Animals spread pollen and seeds in a more
targeted fashion, and to a wider area, than wind or water usually
do.
6. D
The heterotroph hypothesis suggests that anaerobic
heterotropic organisms may have evolved first, releasing carbon
compounds into the atmosphere and allowing the process of photosynthesis
to evolve. Autotrophs then consumed the carbon dioxide. The oxygen released
as waste facilitated the evolution of aerobic organisms. It would
not make sense that anaerobic and aerobic organisms would evolve
together. The latter would thrive in an oxygen-rich atmosphere,
and the former would rely on other molecules. Autotrophs require
carbon dioxide, which was not available in great quantity in the
ancient atmosphere of the Earth. Chemosynthesis is an autotrophic
process and did not contribute to the evolution of heterotrophs.
7. D
Lamarck argued that gradual changes acquired by individuals
over a lifetime were passed on to offspring. Use enhanced or amplified
a trait while disuse reduced it. Lamarck did not discuss the idea
of recessive inheritance, and natural selection was an element of
Darwinian evolution.
8. A
When a population is unable to interbreed, speciation
occurs. Adaptive radiation is a specific type of speciation, but
it refers to speciation that occurs by means of competition for
a niche, not through geographical isolation. Convergent evolution
occurs when two different species that have some similar
functions develop similar-looking body parts. Natural selection is
always happening; the diversion of the river does not begin natural
selection. Lamarckian evolution never occurs, since it is an incorrect
theory.
9. C
The situation described in the question only covers
one generation of penguins. Evolution and speciation take a lot
more time than one generation to begin to function, but natural selection
occurs within a generation by picking out the most fit individuals.
10. D
Of the organisms in the answer choices, only birds
and reptiles lay hard eggs. Reptiles do not provide parental care
for their young, while birds do.
