Answer:
Sigma factors bind to the promoter region of a particular gene and facilitating the binding of RNA Polymerase to the promoter region (formation of the RNA polymerase holoenzyme complex) in order initiate transcription of the gene.
Put simply - Helps RNA Polymerase do it's job.
Gravitational.....................
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
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Determine whether the following symbols are universal or contextual. In "The Nightingale and the Rose,"
Oscar Wilde uses a red rose as a symbol for love. In To Kill a Mockingbird, Harper Lee uses a mockingbird as a symbol for innocence.
In A Little Princess, Frances Hodgson Burnett uses hot buns as a symbol for the connection between the main character and a poor street child.
In "The Water of Life," the Brothers Grimm use water as a symbol for life.
