Lancelet is a chordate but not a vertebrate because it lacks a backbone
Explanation:
The subphyla of the phylum Chordata are - Vertebrata, Urochordata and cephalochordate
Those chordates with a structural backbone belong to Vertebrata.
Urochordates and cephalochordates lack a backbone and hence are termed invertebrate chordates.
Lancelet is an invertebrate chordate of the subphylum – Cephalochordata.
The lancelets consist of a notochord that extends right from the head till the tail at the dorsal surface. The notochord acts like the backbone and provides support and a semi-flexible structure to aid in the movement of the organism.
They lack a developed nervous system like vertebrates but only has a dorsal nerve tube
.
Answer:
true
Explanation:
because land environment is different from water environment .
Hope it help you
The correct answer is: (a) RNA polymerase (along with its sigma subunit) can initiate transcription on its own.
More differences between prokaryotic and eukaryotic transcription:
• In prokaryotes transcription occurs in the cytoplasm (unlike in eukaryotes in nucleus) and it is simultaneous with translation,
• In prokaryotes there is only one type of RNA polymerase (in eukaryotes there are three types of them).
• There is no sigma subunit in eukaryotes, the initiation of transcription begins thanks to initiation factors.
• Promoter region in prokaryotes contains pribnow box, while in eukaryotes it contains TATA and CAT box.
