The Hox genes came to regulate each of the following in what sequence, from earliest to most recent?

1. identity and position of paired appendages in protostome embryos

2. formation of water channels in sponges

3. anterior-posterior orientation of segments in protostome embryos

4. positioning of tentacles in cnidarians

5. anterior-posterior orientation in vertebrate embryos

#Question id: 7757

#SCPH06 I Botany

#Question id: 3866

#SCPH01 Biochemistry

Which of the following statements about E. coli RNA polymerase (core enzyme) is false?

#Question id: 10906

#SCPH06 I Botany

The pressure-flow model explains phloem translocation as a flow of solution (bulk flow) driven by an osmotically generated pressure gradient between source and sink.

a) Phloem translocation, both active and passive mechanisms were considered. All theories, both active and passive, assume an energy requirement in both sources and sinks.

b) In sources, energy is necessary to move photosynthate from producing cells into the sieve elements. This movement of photosynthate is called phloem loading.

c) In sinks, energy is essential for some aspects of movement from sieve elements to sink cells, which store or metabolize the sugar. This movement of photosynthate from sieve elements to sink cells is called phloem unloading.

d) The Active mechanisms of phloem transport further assume that energy is required in the sieve elements of the path between sources and sinks simply to maintain structures.

From the given statements find out the correct for pressure-flow model.

#Question id: 8948

#SCPH06 I Botany

#Question id: 11916

#SCPH06 I Botany

Which one of the following  features of an later community?