During gastrulation in sea urchins, which forms first, the mouth or the anus?

What will be an ideal response?


the anus

Biology & Microbiology

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The deposits of the following phytoplankton are used commercially in polishes and filtering devices:

a. dinoflagellates. b. foraminiferans. c. coccolithophores. d. diatoms. e. radiolarians.

Biology & Microbiology

The reactions of fermentation function to produce ________ molecules for further use in glycolysis.

A. NADH B. glucose C. ATP D. NAD+ E. pyruvic acid

Biology & Microbiology

A DNA library is

A. a line of bacteria that contains a DNA fragment of interest. B. a collection of recombinant vectors containing DNA fragments of a given organism. C. a series of restriction enzymes that can be used to produce a variety of sizes of DNA fragments. D. a collection of books about clones. E. a collection of recombinant plasmids containing a particular gene from many different organisms.

Biology & Microbiology

In a survivorship curve, a type III species, like most insects and plants, is a species that has

A. a strong possibility of becoming extinct in a relatively short period of time. B. an equal probability of dying at any age. C. an extremely long life span. D. the highest probability of dying at a very young age. E. the highest probability of dying as it reaches its maximum life span.

Biology & Microbiology