All GRE Subject Test: Biology Resources
Example Questions
Example Question #2 : Plant Evolution
Which of the following refers to the principle of alternation of generations in plants?
The differences between a tree and a seed
A life cycle that includes a multicellular haploid stage
The need for external pollinators
Gamete-producing sporophytes
A life cycle which includes a unicellular haploid stage
A life cycle that includes a multicellular haploid stage
Plants have a multicellular haploid stage called the gametophyte. Gametophytes () produce gametes () through mitosis, which combine to produce a zygote (). The zygote grows into a multicellular, diploid sporophyte (), which produces spores () through meiosis. Those spores give rise to multicellular gametophytes.
Example Question #1 : Plantae
Fill in the blanks.
The __________ generation is dominant in the bryophyte life cycles, and the __________ generation is dominant in seedless vascular plants.
sporophyte . . . gametophyte
sporophyte . . . sporophyte
gametophyte . . . sporophyte
gametophyte . . . gametophyte
gametophyte . . . sporophyte
Bryophytes are nonvascular plants, such as mosses. Gametophytes are species that have haploid cells during their mature lives, while sporophytes are predominantly diploid during their adult phases.
Bryophytes have the gametophyte generation as dominant, with the sporophytes relying on the parental gametophyte. Starting with the evolution of seedless vascular plants, the gametophytes become reduced and are no longer the dominant life cycle. By the formation of angiosperms (seed plants), the gametophytes have become dependent on the parental sporophyte.
Example Question #2 : Plant Biology
Which of the following structures would be found in a tracheophyte, but not in a bryophyte?
Cell walls
Chloroplasts
Plasmids
Xylem
Xylem
All plants can be classified as either bryophytes or tracheophytes. Plants that contain transport vessels (xylem and phloem) are tracheophytes, while those without transport vessels are bryophytes. All plants contain cell walls and chloroplasts, but only a tracheophyte would contain xylem. Plasmids are structures that are almost exclusively found in bacteria or protozoans.
Example Question #1 : Evolution
Which of the following is false of the phylum chordata?
They have a coelom
They have a notochord at some point in their development
They are protostomes
They have bilateral symmetry
They are protostomes
All chordates are deuterostomes, not protostomes. During early development, the formation of the blastopore leads to the growth of the digestive tract. In protostomes, the blastopore develops into the mouth, while in deuterostomes it becomes the anus.
All chordates have a notochord during development, which eventually gives rise to the nervous system. Chordates also have a coelom, or fluid filled cavity, somewhere within the body and they all exhibit bilateral symmetry.
Example Question #1 : Speciation And Phylogenetics
Which of the following is not necessary for designation as a chordate?
I. A notochord
II. Vertebrae
III. A post-anal tail
IV. Gill arches
V. A dorsal, tubular nervous system
III
V
II
IV
I
II
Chordates must have, at some point in their embryogenesis, all features except vertebrae. Although the vast majority of chordates are vertebrates, Amphioxus has only a notochord. This primitive organism never develops vertebrae. Man has gill arches, and remnants of these are seen in certain congenital malformations. The notochordal remnants can give rise to the tumor known as a chordoma. The brain has ventricles (it is tubular) and it is certainly dorsal. Finally, human tail persists in about one per million live births.
Example Question #1 : Speciation And Phylogenetics
Which of the following statements about chordates is true?
Their anus forms from the blastopore
They are protostomes
All chordates are vertebrates
They lack a coelom
Their anus forms from the blastopore
The phylum chordata has a few key characteristics. They are deuterostomes, meaning that the anus arises from the blastopore. They have a coelom that arises from the mesoderm during development, and at some point they have a tail, pharyngeal slits, and a notochord.
Vertebrata is a subphylum of chordata, so not all chordates are vertebrates (though all vertebrates are chordates).
Example Question #1 : Identifying Animals
Which of the following organelles is/are mainly present in animal cells?
I. Peroxisome
II. Centrioles
III. Flagella
II only
I and III
III only
I only
II and III
II only
Centrioles are generally only found in animal cells, but have been found in a variety of eukaryotes. There are a small subset of plants that do contain centrioles. Some plant cells have flagella and peroxisomes.
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