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Ask QuestionPosted by Shreya S❤ 5 years, 4 months ago
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Posted by Sneha Sahu 5 years, 4 months ago
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Gaurav Seth 5 years, 4 months ago
Lichens are the composite or dual organisms representing a symbiotic association between a fungus and alga. The fungal partner is called mycobiont whereas algal partner is called phycobiont. Algae prepares food for fungi and fungi provides shelter and absorbs mineral nutrient and water for its partner. Lichens grow on barren rocks, cooled volcanic lava and icy tundra soils. They can tolerate extreme dessication but not the polluted air. Depending upon the shape, the three morphological forms of lichens are :
(a) Crustose lichens : They are thin membranous forms of lichens attached to the substratum in the form of a crust, e.g., Khizocarpon, Haematoma etc.
(b) Foliose lichens : They have flat, lobed and leaf like body attached to the substratum by fungal hyphae called rhizines. e.g., Parmelia.
c) Fruticose lichens : They have branched and small bushy bodies, which is attached to the substratum by discs, e.g., Usnea and Cladonia etc.
Importance of lichens :
(a) Litmus used as pH indicator was prepared from lichen Rocella tinctorea.
(b) Scented incense or perfumes are obtained, from Ramalina and Evernia.
© Lichens acts as pollution indicators.
(d) Certain lichens are source of food for grazing animals.
Posted by Anbu Annadurai 5 years, 4 months ago
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Sriram Nagarajan 5 years, 4 months ago
Yogita Ingle 5 years, 4 months ago
Serum consists of plasma from which fibrinogens have been removed. It contains antibodies to counter act the effect to toxic substances of micro-organisms. It is the plasma without the clotting factors.
Sintu Prajapat 5 years, 4 months ago
Posted by Anbu Annadurai 5 years, 4 months ago
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Gautami Patil 5 years, 4 months ago
Yogita Ingle 5 years, 4 months ago
The heart is roughly cone shaped hollow organ. It is approximately the size of owner’s closed fist and weighs about 250-300 gm in female and 300-350gm in the male. The heart lies in the thoracic cavity in the space between the lungs (mediastinum) anterior to the vertebral column and posterior to the sternum. The heart consists of 4 chambers. At first, the heart is divided into the right and left side by the septum. Each side is further divided into 2 chambers each by the atrioventricular valve. The upper two chambers are called atrium and lower two are called ventricles. Atrium are thin-walled chamber separated by an interauricular septum
The right atrium receives impure blood from the body through the opening via superior and inferior vena cava. Ventricles are a thick-walled chamber. separated by the thick inter-ventricular septum.
Posted by Prerna Goswami 5 years, 4 months ago
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Gaurav Seth 5 years, 4 months ago
The animal kingdom is also classified on the basis of the level of organization other than symmetry, germ layers, and body cavity. Though the animals are multicellular, the level of organization varies from cellular and tissue level.
Cellular level: In this structural organization, each cell of the organism performs all life process e.g., Porifera.
Tissue level: In this structural organization, a tissue is made up of group similar type of cells that perform same functions and group of the same type of tissues forms organs. Such organs perform a specific function for the body.
Posted by Unique #Seraj Ali ??? 5 years, 4 months ago
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Posted by Palak Awasthi 5 years, 4 months ago
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Sriram Nagarajan 5 years, 4 months ago
Gaurav Seth 5 years, 4 months ago
- The name Cnidaria is derived from the cnidoblasts or cnidocytes , which contain the stinging capsules or nematocytes present on the tentacles and the body.
- Cnidarians exhibit tissue level of organisation and are diploblastic, digestion is extracellular and intracellular, and have a central gastro-vascular cavity with a single opening, hypostome.
- Cnidarians like corals have a skeleton composed of calcium carbonate and exhibit two basic body forms called polyp and medusa, polyp is sessile and cylindrical form like Hydra, whereas, the latter is umbrella-shaped and free-swimming like Aurelia.
- Cnidarian which exist in both polyp and medusa forms exhibit alternation of generation called as
- Polyps produce medusae asexually and medusae form the polyps sexually (e.g., Obelia).
- Examples- Physalia (Portuguese man-of-war), Adamsia (Sea anemone).
Posted by Nikhil 526 5 years, 4 months ago
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Sriram Nagarajan 5 years, 4 months ago
Syed Ali Shbeeh 5 years, 4 months ago
Posted by Vaishali ..... 5 years, 4 months ago
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Vaishali ..... 5 years, 4 months ago
Posted by Yadav Krishna 5 years, 4 months ago
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Vaishali ..... 5 years, 4 months ago
Posted by Pavithra Karthikeyan 5 years, 4 months ago
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Gaurav Seth 5 years, 4 months ago
DISORDERS OF RESPIRATORY SYSTEM
- Asthma is a difficulty in breathing causing wheezing due to inflammation of bronchi and bronchioles.
- Emphysema is a chronic disorder in which alveolar walls are damaged due to which respiratory surface is decreased.
- Occupational respiratory disorders include lung damage due to inflammation, which ultimately leads to fibrosis.
Posted by Rajesh Chandra 5 years, 4 months ago
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Gaurav Seth 5 years, 4 months ago
Secondary or intermediate host - An organism in or on which a parasite develops to an adult but not sexually mature stage.
It is an organism that harbors the sexually immature parasite and is required by the parasite to undergo development and complete its life cycle.
Posted by Rajesh Chandra 5 years, 4 months ago
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Gaurav Seth 5 years, 4 months ago
This type of regeneration has little growth and depends upon tissues repatterning. For eg., Hydra grows by loss of cells from its end and by budding. When cut into two, the upper part develops into foot while the lower part develops into the head. The formation of nearby heads is inhibited by the head region.
Posted by Rajesh Chandra 5 years, 4 months ago
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Gaurav Seth 5 years, 4 months ago
Answer: Metagenesis is the phenomenon in which one generation of certain plants and animals reproduce asexually, followed by the sexually reproducing generation. ... Coelenterates exhibits metagenesis (e.g., Obelia) where polyp form alternates with medusa in its life cycle.
Posted by Rajesh Chandra 5 years, 4 months ago
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Meghna Thapar 5 years, 4 months ago
The nervous system has two main parts: The central nervous system is made up of the brain and spinal cord. The peripheral nervous system is made up of nerves that branch off from the spinal cord and extend to all parts of the body. The diffuse nervous system is the most primitive nervous system. In diffuse systems nerve cells are distributed throughout the organism, usually beneath the outer epidermal layer.
Posted by Rahul Sehgal 5 years, 4 months ago
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Posted by Anjana Jangid 5 years, 4 months ago
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Aditi Rao 5 years, 4 months ago
Aditi Rao 5 years, 4 months ago
Posted by Rahul Sehgal 5 years, 4 months ago
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Posted by Rahul Sehgal 5 years, 4 months ago
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Meghna Thapar 5 years, 4 months ago
The leaves of ferns are often called fronds. Fronds are usually composed of a leafy blade and petiole (leaf stalk). Leaf shape, size, texture and degree of complexity vary considerably from species to species. A fern leaf or frond. They have vascular tissue with leaf blades and a stalk, which runs from the base of the frond to the tip. Their primary roles are in photosynthesis and reproduction as well as providing many other uses for ferns.
Posted by Mitranshu Panigrahi 5 years, 4 months ago
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Meghna Thapar 5 years, 4 months ago
A flagellum (/fləˈdʒɛləm/; plural: flagella) is a lash-like appendage that protrudes from the cell body of certain bacteria and eukaryotic cells termed as flagellates. A flagellate can have one or several flagella. Flagella are key structures concerned with bacterial motility. Nevertheless, bacteria that lack flagella may still be motile. A type of gliding motility can be achieved by the flexible movement of the whole cell. This is mainly observed on solid media, whereas flagellar motion is common to liquid environments. The primary purpose of cilia in mammalian cells is to move fluid, mucous, or cells over their surface. Cilia and flagella have the same internal structure. The major difference is in their length. Cilia and flagella move because of the interactions of a set of microtubules inside.
Posted by Sanjay Kumar 5 years, 4 months ago
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Gaurav Seth 5 years, 4 months ago
.Four Kingdom Classification System
The four kingdom classification system included Monera in addition to Protista, Plantae and Animalia. Studies with electron microscope made it clear that bacteria and related organisms have a different nuclear structure as compared to others. They are* prokaryotes, thus kingdom-Monera was created by Copeland (1956). Fungi continued to remain with Plantae in this system.
Posted by Ritika Pal 5 years, 4 months ago
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Gaurav Seth 5 years, 4 months ago
The ordering of organisms into groups on the basis of non-evolutionary features (e.g. the grouping together of plants according to the number and situation of their stamens, styles, and stigmas rather than their evolutionary relationships). An artificial system of classification is based upon one or a few easily observable characteristics, and is devised and used for a limited purpose where convenience and speed are important. It conveys little information.
Posted by Tarun Kumar 5 years, 4 months ago
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Posted by Aditi Rao 5 years, 4 months ago
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Yogita Ingle 5 years, 4 months ago
- Racemose: In racemose types of inflorescence the main axis grows continuously and flowers are present laterally on the floral axis. Flowers are present in an acropetal manner
- Cymose: In the cymose type of inflorescence the main axis does not grow continuously. A flower is present terminally on the main axis. The flowers are borne in a basipetal order. The main axis has limited growth
Posted by Aditi Rao 5 years, 4 months ago
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Yogita Ingle 5 years, 4 months ago
A flower arises in the axil of a leaf like structure called bract. Flowers with bracts are called bracteate and those without bracts are called ebracteate. The terminal part of the axis of the flower is the receptacle or thalamus. The receptacle contains sepals, petals, stamens and carpels.
Posted by Exquisite Lo.. 5 years, 4 months ago
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Gaurav Seth 5 years, 4 months ago
A person lying in comma neither responds to environmental stimuli nor has self-consciousness. He/she is supported by machines to carry out the vital life processes and he/she is brain-dead. Some of these patients never come back to normal life. Such persons can neither be considered as living nor non-living.
Posted by Jasmeen Kaur 5 years, 4 months ago
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Yogita Ingle 5 years, 4 months ago
Chemotaxonomy is the identification and classification of organisms based on similarities and differences in biochemical composition. Cytotaxonomy can also be defined as the classification of organisms based on differences at the biochemical level especially in the amino acid sequences of common protein.
Akash Pandey 5 years, 4 months ago
Posted by Boparai Boparai 5 years, 4 months ago
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Jasmeen Kaur 5 years, 4 months ago
Posted by Boparai Boparai 5 years, 4 months ago
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Gaurav Seth 5 years, 4 months ago
Protection, anchorage and absorption for alga
Lichen is a symbiotic association between blue-green algae and fungus. In this, blue-green algae provide food and nutrition obtained by photosynthesis. In turn, fungus provides protection, anchorage and absorption of water and nutrition from soil for algae.
Posted by Boparai Boparai 5 years, 4 months ago
- 1 answers
Bhargavee Tripathi 5 years, 4 months ago
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Anjali Yadav 5 years, 4 months ago
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