A geneticist is trying to recreate a strand of DNA from a crime scene investigation. The strand of DNA recovered from the scene was 1800 bases long. The geneticist has determined that the strand contained 425 thymine nucleotides. Based on this information, identify the number of cytosine nucleotides

475

Explanation:

The strand is only made up of Adenine, Thymine, Cytosine and Guanine. There will be the same number of Adenine as there are Thymine and the same number of Cytosine as there are Guanine.

We know there are 425 Thymine. This means there are also 425 Adenine. Therefore, you would subtract 850 (425x2) from 1800 to find the amount of Cytosine and Guanine left, which is 950.

Out of the 950, half will be Cytosine and half Guanine. 950/2 is 475.

organisms that lack symmetry are called asymmetrical and belong to phylum porifera/sponges.

organisms with specialized stinging cells belong to phylum cnidaria. stinging cells are called cnidoblast cells.

cnidarians show two morphological forms : polyp (sessile) and medusa (mobile)

filter feeding is observed in porifera members.  

alternation of generation is observed in coelenterata or cnidaria. there is alternation of asexual polyp form and sexual medusoid form. it is also referred as metagenesis.