Membrane -bound organelles are absent in
Streptococcus is a spherical, gram positive bacterium, Membrane bound organelles are absent in prokaryotes.
Fungi (e.g, Saccharomyces) represents a group of eukaryotic, non-photosynthetic heterotropic organisms. Algae(e.g.Chlamydomonas) is a group of chlorophyll bearing, autotrophic, thalloid plants.
Plasmodium is a genus of protists. Infection by these organsims is know as malaria.
Which one of the following has its own DNA?
In mitchondria, the inner membrane space is filled with a matrix which contains dense granules along with ribosomes and mitchondrial DNA.The mitochondrial DNA is circular in nature. There number varies from 2-6.Besides DNA, a mitochondrion has RNA and its ribosomes also. Thus, a complete protein synthesizing machinery is present in mitcochondria, which suggeststhe semi -autonomuous nature of mitochondria Dictyosome, lysosome and peroxisome do not have their own DNA.
Which one of the following structures between two adjacent cells is an effective transport pathway?
The primary cell wall contains many small openings or pores situated in the primary pit fields.The cytoplasm of adjacent cells communicates through the pores by means of cytoplasmic bridges called plasmodesmata. The plasmodesmata permit circulations of fluid and passage of solutes between cells.
The chief water conducting elements of xylem in gymnosperms are
The tracheids are elongated, angular dead cells with hard lignified wide lumen and narrow end walls. The walls of tracheids posses different types of thickenings and the unthickened areas of its wall allow the rapid movement of water from one tracheid to another. Tracheids are the characteristic cells types of xylem tissue in gymnosperms and pteridophytes, where they are chief elements of water conduction.
In unilocular ovary with a single ovule, the placentation is
In basal placentation, the ovary is bicarpellary, syncarpous and unilocular and a single ovule is borne at the base of ovary, eg, marigold.
In marginal placentation, the ovary is simple unilocular and the ovules are arranged along the margin of ovary eg, pea.
The kind of epithelium which forms the inner walls of blood vessels is
ciliated columnar epithelium
which one of the following is not a micronutrient?
The essential elements, which are required by plants in comparatively large amounts are called as macro elements, e.g, C,H, O, N, P,K,Ca,S,Mg,Fe. The elements, which are required in very small amount by the plants are called micro elements, e.g, Zn, Mn, B, Cu, Mo and Cl
An element playing important role in nitrogen fixation is
Molybdenum is absorbed as molybdate by plants. It is involved in nitrogen metabolism including nitrogen fixation. It is a component of enzyme nitrogenase and acts as an enzyme activator. Its deficiency cause chlorosis and necrosis, whiptail of cauliflower and premature leaf fall.
Copper is absorbed by the plant in ionic form. Its deficiency causes necrosis, die back in Citrus, reclamation in legumes.
Manganese is absorbed by the plants as a bivalent ion. It acts as the enzyme activator. Its deficiency causes interveinal chlorosis as well as yellowing of starch and their subsequent degenerate.
Zinc is needed for biosynthesis of IAA and also acts as the enzyme activator. Its deficiency causes chlorosis, little leaf, rosette, the white bud of maize and mottling of leaves.
Single -celled eukaryotes are included in
Kingdom - Protista includes all unicellular eukaryotic organisms like flagellates, diatoms, dinoflagellate, slime mould, Sarcodina, etc.
Fungi represent a group of eukaryotic achlorophyllous, non - photosynthetic heterotrophic organisms of diverse forms, sizes, physiology and mode of reproduction. The members of Archaea (Archaebacteria) are prokaryotes and include the extreme halophiles, the thermoacidophiles and the methanogens.
Monera is the kingdome, that in older classifications contain all prokaryotes.
One example of animals having a single opening to the outside that serves both as mouth as well as anus is
Fasciola hepatica (sheep liver fluke) belongs to phylum - Platyhelminthes. These worms have an incomplete alimentary canal, there is a single opening for both ingestion and egestion. This is also called as blind sac body pain.