In dicotyledonous stems of temperate trees, during secondary growth, vascular cambial ring(narrow layer of thin-walled cells) produces secondary phloem towards outer side and secondary xylem or wood towards inner side. So, the correct option is ‘vascular cambium’.
In old trees , the greater part of the secondary xylem is dark brown due to the deposition of the organic compounds like resins , gums , oils aromatic substance and tannins in the innermost layers of the stem . These substances make it hard, durable and resistant towards the attack of microorganisms and insects. This region comprises dead elements with highly lignified walls and it is known as the... more HEARTWOOD. The HEARTWOOD doesn't conduct water but it gives mechanical support to the stem.
The cardiac skeleton provides the rigidity to prevent the dilatation of valves and outflow tracts , give attachment to valves leaflets and myocardium and electrically isolates the atria from the ventricle. The presence of OS CORDIS is a regular finding in the large ruminants such as in cattles, like ox, buffaloes, sheeps and etc but it is not reported in other mammals. In cattles the OS CORDIS is... more located near the junction of interatrial and interventricular septa and extends anteriomedially into the right atrioventricular ring..... So , we can say that OS CORDIS is found in the cattles.
Multiple alleles refer to the presence of more than two alternate forms of a gene which should be accommodated on two loci on a homologous pair. This is facilitated by the presence of more than one allele on the same locus of a chromosome provided one allele is present at a locus at a time. Thus, the correct answer is option D.
Tender coconut water is a clear liquid found inside of the young tender coconut. During the nuclear phase of the development, it provides as a termination for the endosperm of the coconut. In the nuclear endosperm formation, free-nuclear divisions are repeatedly done; if a cell wall is developed it will form after free-nuclear divisions. Commonly referred to as liquid endosperm. Coconut water from... more a tender coconut is an example of this process i.e, free nuclear endosperm.
PCR and RFLP are the methods used for genetic fingerprinting. DNA fragmentation plays an important part in forensics, especially that of DNA profiling. Restriction fragment length polymorphism (RFLP) analyses the variable lengths of DNA fragments which are formed from the digestion of a DNA sample with a restriction endonuclease. They are then hybridized with DNA probes that bind to a complementar... morey DNA sequence in the sample. In polymerase chain reaction (PCR), This sample DNA is amplified from a single copy to millions of copies of DNA. It used to amplify a specific region of a DNA strand.
Correct option (a) These are parenchyma cells with thickened lignified walls Explanation Sclereids are broad sclerenchyma cells which may be oval, spherical, cylindrical, or stellate ln structure. Sclereids develop from sclerenchyma cells, occur singly or in groups to provide stiffness. These may be of different types, such as brachysclereids (stone cells) found in grit of pear, apple, macrosclere... moreids.
Megasporangium" is a technical term given to an ovule, which contains nucellus, integuments and funiculus through which it is adhered to the placenta. In simple words, megasporangium along with its protective coverings, the integuments, is called ovule. Integuments cover an opening called micropyle, through which pollen tube enters the ovule during fertilisation. Thus, ovule is an integumented deh... moreiscent megasporangium with single megaspore. So, the correct answer is C.
Riccia belongs to the genus liverworts. The gametophytic plant body of Riccia is a branched dorsiventral thallus. The sex organs antheridia and archegonia are embedded in the thallus. The antheridium is embedded in an antheridial chamber that opens on the dorsal side of the thallus. The archegonium is linked to the thallus by a stalk. Thus the correct answer is option C.
Both radio and light waves are EM waves, just in different frequency ranges. The wavelength of visible light is typically around the 600 nm range, which is 6/1000 of a millimeter (very small!). Radio waves on the other hand, often wave wavelengths of a few yards long. For a wave to diffract around an object, the size of the object must be on the same order of the wavelength of the wave.hence, opti... moreon B is right ans
The crofter was old man without wife and child, he was happy to get someone to talk in his lonlyness, to be relieved of his boredom and monotony. This is the reason he was so talkative and friendly with peddler
Mo is required in the synthesis of nitrogenase and nitrate reductase and is present in the form of molybdoflavoprotein in these enzymes. These enzymes are crucial for fixing atmospheric nitrogen to the usable forms in plants. Hence, B is the correct answer.