Yeah yeah so :D,
Large polar molecules can only cross the membrane with the help of protein named channel protein and carrier protein.
So, this both proteins act like a gate, the large molecules enter the protein and the protein let the large molecules in to the membrane. (see the picture so that you can understand more, its carrier protein)
the only difference between channel protein and carrier protein is, channel proteins has fixed shape while carrier protein can flip.
Answer:
<h2>letter A</h2>Explanation:Whittaker placed bacteria in their own kingdom, Monera, because of fundamental organizational differences between prokaryotic bacterial cells, which lack membrane-enclosed nuclei and organelles , and the eukaryotic cells of other organisms that possess internal membranes. Plantae, Fungi, and Animalia consist of complex, multicellular eukaryotic organisms that differ from each other in details of cell structure and in how they secure and process energy. Protista is a collection of single-celled eukaryotic organisms and simple multicellular forms, some animal-like, some plantlike.
<h2>letter b</h2>Molecular evidence, particularly from ribosomal ribonucleic acid (RNA), suggests that the five-kingdom scheme is also too simple. Some biologists believe that Protista should be partitioned into three or more kingdoms. Similarly, kingdom Monera contains two very biochemically distinct groups of prokaryotes: archaebacteria, and eubacteria. A proposed system acknowledges this ancient evolutionary split by creating a higher level of classification, domain, above kingdom. This system distinguishes three domains: Archaea, Eubacteria, and Eukarya (containing protists, plants, fungi, and animals).
