Living members of the lineage ____ are the ray-finned fishes, with fins supported by thin and flexible bony rays. This lineage includes over 95 percent of the living species of fishes.
a. Petromyzontoidea
b. Chondrichthyes
c. Actinopterygii
d. Myxinoidea
e. Sarcopterygii
C
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Which chromosomal mutation will cause Williams syndrome?
A. duplication B. deletion C. trisomy D. translocation E. inversion
It has been predicted that genes may be involved in smoking initiation and/or current smoking behavior
Previously, large twin and family studies have provided evidence of this and an estimate of heritability (genetic contribution) of 37-55% for initiation and 46-59% for current smoking, depending on gender. A large group of researchers from several institutions composed a pathway- or-systems-based series of studies including SNP analysis, cellular location and protein interaction, replication with other samples, statistical analysis, and bioinformatics. What is a likely result? A) The study is unlikely to produce meaningful results because it is too diffuse in its methods. B) The samples used also correlate with behaviors like depression, often associated with smoking, and they may be finding depression-associated genes. C) Two specific genes, one for a transporter protein and one for an opioid receptor, are clearly shown to be causative in all members of each sample. D) A group of genes that tend to code for proteins with similar biological function have been identified to contribute significantly. E) Genome-wide association studies are of no practical use in studying human behaviors.
The cytoskeleton has several primary functions. The first and most obvious is that it acts as an interior skeleton that supports the rest of the cell. What is another function of the cytoskeleton?
A) It provides a communication network whereby chemo-electrical signals can be sent from one area of the cell to another. B) It creates a durable outer covering to increase the strength and rigidity of the cell. C) It provides a series of tracks along which vesicles can move throughout the cell. D) It connects one cell to another.
Adult tunicates have lost two embryonic features: the tail and the ________
Fill in the blank(s) with correct word