20. Which of the following statements is/are correct?
A. Molluscs can live in marine, and freshwater habitats but do not live in terrestrial habitats.
B. Given the following on the organism:
I. An animal
II. Multicellular
III. has tissues
IV. has a digestive tract
V. exhibits bilaterally symmetry as an adult
This organism could be a member of the Phylum Mollusca
C. Molluscs can produce a shell and the presence of a shell at one point in development is a requirement for inclusion into this phylum.
D. Lobsters are members of the phylum Mollusca
E. Molluscs have three main body parts, a muscular foot, a visceral mass, and a head

Option C and E.

Explanation:

Phylum molluscs are invertebrates animals and they are the second largest phylum in the animal kingdom.

Some molluscs live in marine habitats and numerous species live in freshwater and terrestrial habitats.

Molluscs are coelomates and have three distinct features which are mantle( for breathing and excretion) , radula and nervous system. Molluscs have shell and have three main parts which are head, visceral mass and muscular foot. Examples of molluscs are snails, periwinkles, squids, oysters, octopus e.t.c.

"1. it should be, it has been for about 20 years, and it's really not much different in the end than breeding animals to have particular traits. there are always concerns about genetically engineered animals/plants affecting the environment in unexpected negative ways, but i can't think of an example where the fears didn't turn out to be baseless.  

first, as you point out, it would be a great advance in pharmacology, to be able to tailor drugs and their doses to me. the pros involve better medical treatment. the cons involve privacy issues like insurance companies denying coverage to people with genetic risk factors. looking at dna markers wouldn't affect the frequency of genetic diseases, but it would allow detection of them earlier. and ok, actually i suppose that if people used this information to avoid having children with genetic diseases, some might decrease in frequency."

yes it is weird but true