GRE Subject Test: Biology : Animalia

Study concepts, example questions & explanations for GRE Subject Test: Biology

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Example Questions

Example Question #2 : Evolution

Which of the following is false of the phylum chordata?

Possible Answers:

They are protostomes

They have a notochord at some point in their development

They have a coelom

They have bilateral symmetry

Correct answer:

They are protostomes

Explanation:

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 : Evolution

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

Possible Answers:

III

IV

V

II

I

Correct answer:

II

Explanation:

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 : Animalia

Which of the following statements about chordates is true?

Possible Answers:

All chordates are vertebrates

Their anus forms from the blastopore

They are protostomes

They lack a coelom 

Correct answer:

Their anus forms from the blastopore

Explanation:

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 : Animalia

Which of the following organelles is/are mainly present in animal cells?

I. Peroxisome

II. Centrioles

III. Flagella

Possible Answers:

I only

II only

II and III

III only

I and III

Correct answer:

II only

Explanation:

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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