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๐™ˆ๐™ค๐™ง๐™ฅ๐™๐™ค๐™ก๐™ค๐™œ๐™ฎ || The Leaf || Parts of a ๐™‡๐™š๐™–๐™› ||

                      ๐™ˆ๐™ค๐™ง๐™ฅ๐™๐™ค๐™ก๐™ค๐™œ๐™ฎ The Leaf:- The leaf is a lateral, generally Battened structure borne on the stem. It develops at the node and bears a bud in its axil. The axillary bud later develops into a branch. Leaves originate from shoot apical meristems and are arranged in an acropetal order. They are the most important vegetative organs for photosynthesis. Parts of a ๐™‡๐™š๐™–๐™›:- The leaves also consist of two lateral outgrowths called stipules at their bases. A typical leaf has three main parts. i. Leaf ๐˜ฝ๐™–๐™จ๐™š (Hypopodium) The leaf is attached to the stem by the leaf base. Monocots, the leaf base is said to be sheathing as it expands and partially and wholly surrounds the stem. In dicots, the leaf base bears two lateral outgrowths called stipules. In some leguminous plants, the leaf base may become swollen which is called the pulvinus. Leaves with stipules are called stipulate and those without them are termed as ?...

๐™ˆ๐™ค๐™ง๐™ฅ๐™๐™ค๐™ก๐™ค๐™œ๐™ฎ || ๐˜ฝ๐™ช๐™ก๐™—๐™ž๐™ก๐™จ ||

                   ๐™ˆ๐™ค๐™ง๐™ฅ๐™๐™ค๐™ก๐™ค๐™œ๐™ฎ ⚜Phylloclade ⚜These are green, flattened structures bearing several nodes and internodes. The true leaves are reduced to spines or scales. They show unlimited growth. Some phylloclades also store food and water. The phylloclades are examples of some xerophytic plants, e.g., Opuntia (nagaphani), Casuarina, Euphorbia. Cladodes (Cladophylls) . ⚜They are green photosynthetic stems generally one inter node long. These develop by the modification of only stem branches of limited growth and are green (photosynthetic). The true leaves of the plant are reduced to scales or spines, e.g., Ruscus, Asparagus. ⚜๐˜ฝ๐™ช๐™ก๐™—๐™ž๐™ก๐™จ These are modified vegetative or floral buds arising in the axil of scale or foliage leaves. The bulbil helps in vegetative propagation, e.g., Lilium, Agave, Dioscorea (wild yam), Oxa๐™ก๐™ž๐™จ.

Very Important Points of NCERT ❤️ || Biology ||

 ๐Ÿ’ฅVery Important Points of NCERT ❤️:   ๐ŸŒŸ1. Genetic map discovered by Alfred Sturtevent.  ๐ŸŒŸ 2. Henking trace a specific nuclear structure (X-body) all through spermatogenesis in a few insects (1891).  ๐ŸŒŸ3. Down’s syndrome was first described by Langdon Down (1866)  ๐ŸŒŸ4. DNA (Nuclein) was first identified by Friedrich Meischer (1869).  ๐ŸŒŸ 5. X-ray diffraction data produced by Wilkins & Franklin.  ๐ŸŒŸ 6. Transforming principle was given by Griffith (1928).  ๐ŸŒŸ 7. Biochemical characterisation of transforming principle was given by  Avery, MacLeod & Mc Carty.  ๐ŸŒŸ 8. Unequivoal proof that DNA is the genetic material came from the  experiements of Hershey & Chase (1952).  ๐ŸŒŸ 9. Replication scheme was given by Watson & Crick.  ๐ŸŒŸ 10. Central dogma of biology was given by Crick.  ๐ŸŒŸ 11. The experimental proof that DNA replicates semiconservatively was  given in prokaryotes by Meselson & Stahl (1...

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