Placenta is the structure formed
O2 released in the process of photosynthesis comes from
Plants hormone that induces cell division is
Neurospora is used as genetic material because
Phloem is a tissue found in
N2 content is kept constant in the biosphere due to
out of proteins, lipids and carbohydrates present in a cell membrane, what is true?
Potato is a modified form (outgrowth) of
Of the following taxonomic categories which is the most inclusive (i.e. is the highest in hierarchy)?
Prothrombin which helps in clotting of blood is released by
Myopia is connected with
Most of the red, blue and purple colours of plants are due to a pigment called
Plants developing in dry conditions are
Plants growing on sand are called as
Our skin, when exposed to excess sunlight, becomes dark. This is because our skin pigments called
Ramapithecus and Cro-Magnon man are considered
Normal adult human male has
Plants wilt due to excess of
Poison glands of snakes are homologous to
Radical vascular bundles are those in which
With the help of examples, explain the various types of vascular bundles.
In angiosperms the vascular bundles are mainly of three types (i) radial (ii) conjoint (iii) concentric.
(i) Radial : Presence of radial vascular bundles is the characteristic feature of roots. Those vascular bundles in which xylem and phloem are present on different radii are known as radial vascular bundles. In between xylem and phloem bundles parenchymatous cells are present.
(ii) Conjoint : In these vascular bundles xylem and phloem are present on the same radii. Conjoint vascular bundles may be collateral (phloem is present only outer to xylem) or bicollateral (phloem is present on both sides of xylem). If cambium is present between xylem and phloem then the vascular bundle is known as open, otherwise it is called closed.
(iii) Concentric : Those vascular bundles in which one type of vascular tissue is surrounded by another type are known as concentric vascular bundles. These bundles may be amphivasal or leptocentric(phloem is completely surrounded by xylem) or amphicribal or hardocentric (xylem is completely surrounded by phloem). Amphivasal bundles are found in Dracaena and Yucca. Amphicribal bundles are found in stamens of many dicots etc.
Radical vascular bundles are those in which xylem and phloem occur on the different radii.
Plant bends towards the source of light on account of the movement of curvature known as
Monotremes are unique mammals because they
Plant have ____ while animals lack it.
Osmosis is the flow of solution from higher concentration to a solution of lower concentration through a semi permeable membrane. What is incorrect in this statement?
Ptyalin is an enzyme produced in the