DNA a double-helix like structure, containing multiple nucleotide sequences consisting of a phosphate group, a sugar group, a nitrogenous base, and a hydrogen bond between two nucleotides. The hydrogen bond is weak so the double-helix can "unzip" and make RNA. I hope this helps!
<span>Styrene, or C6H5-CH=CH2, can form even lengthy chains, via free radical polymerization. This involves the breakage of the double bond that allows the addition of another molecule of styrene. Repetition allows the addition of another, and yet another, styrene molecule. The process can be controlled to limit the number of additions.
Another addition polymerization involves carbocations. Double- or triple-bonded compounds interact with acids to form positively charged carbocations. These can combine with additional molecules to form lengthier carbocations capable of further repeating the process.</span>
In order for a cell to differentiate into its specialized form and function, it need only manipulate those genes (and thus those proteins) that will be expressed, and not those that will remain silent. The primary mechanism by which genes are turned “on” or “off” is through transcription factors.
I am 50% sure the answer to your question is no
Answer:
Cycads /ˈsaɪkædz/ are seed plants that typically have a stout and woody (ligneous) trunk with a crown of large, hard, stiff, evergreen and (usually) pinnate leaves. The species are dioecious, therefore the individual plants of a species are either male or female. Cycads vary in size from having trunks only a few centimeters to several meters tall. They typically grow very slowly[3] and live very long, with some specimens known to be as much as 1,000 years old.[citation needed] Because of their superficial resemblance, they are sometimes mistaken for palms or ferns, but they are not closely related to either group.
Cycads are gymnosperms (naked seeded), meaning their unfertilized seeds are open to the air to be directly fertilized by pollination, as contrasted with angiosperms, which have enclosed seeds with more complex fertilization arrangements. Cycads have very specialized pollinators, usually a specific species of beetle. Both male and female cycads bear cones (strobili), somewhat similar to conifer cones.
Cycads have been reported to fix nitrogen in association with various cyanobacteria living in the roots (the "coralloid" roots).[4] These photosynthetic bacteria produce a neurotoxin called BMAA that is found in the seeds of cycads. This neurotoxin may enter a human food chain as the cycad seeds may be eaten directly as a source of flour by humans or by wild or feral animals such as bats, and humans may eat these animals. It is hypothesized that this is a source of some neurological diseases in humans.[5][6]
Cycads all over the world are in decline, with four species on the brink of extinction and seven species having fewer than 100 plants left in the wild.[7] The plant has a very long fossil history, with evidence that they existed in greater abundance and in greater diversity before the Jurassic and late Triassic mass extinction events.
Explanation:
~Dr.Smiley~
(Jane)
