Which of the following is considered the key innovation that started chordates along the evolutionary path that led to vertebrates?

A. A skin covering the entire body to prevent desiccation
B. An internal endoskeleton
C. A flexible rod to which muscles are attached, which allowed lateral movement of the back
D. Amniotic egg
E. A hard shell encasing the body


Answer: C

Biology & Microbiology

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Some strategies for protecting endangered species include the use of DNA profiling to identify illegally traded animal parts and assisted reproduction techniques to help boost population numbers. These techniques are examples of _____

a. biotechnology b. gene pooling c. biosynthetics d. environmental forensics e. DNA cloning

Biology & Microbiology

An advantage of all molecular assays is:

a. the ability to test for C. trachomatis from the same specimen at the same time. b. the ability to use these tests for assessing the successfulness of treatment. c. their role as evidence in medicolegal cases. d. the ability to detect the capsular antigen in body fluids.

Biology & Microbiology

The members of this subphylum have a three-part body plan: a head, thorax, and abdomen. Among

other structures, their head has one pair of antennae and a pair of mandibles, and their thorax has three pairs of walking legs and often one or two pairs of wings.

a. Myriapoda b. Trilobita c. Chelicerata d. Hexapoda e. Crustacea

Biology & Microbiology

The length of day is ____ apt to change and the sunlight is ____ near the equator

a. less; strongest b. less; weakest c. more; strongest d. more; weakest e. equally; constant

Biology & Microbiology