The model is called a double helix because two long strands twist around each other like a twisted ladder. The rails of the ladder are made of alternating sugar and phosphate molecules. The steps of the ladder are made of two bases joined together with either two or three weak hydrogen bonds.
Answer:
the answer is C hope this helped.
Explanation:
Answer:
B
Explanation:
Ferns are in the group pteridophytes. These plants have a vascular system – which also means they have true roots, stem, and leaves-, however, they produce through spores (not seeds like higher plants-gymnosperms and angiosperms). Other than ferns, other plants in the group are horsetails and club-mosses. Unlike in higher plants, where the gametophyte is the dominant phase of the life cycle, the sporophyte is the dominant phase in pteridophytes and other lower plants.
The answer is h It can be split into thin, flat layers. This foliated rock slate is made up of parallel plates, giving it the ability to break into smooth, even and thin layers which are along its cleavage. This characteristic makes slate most suitable for roofing shingles, flooring and flagging.