Welcoem to posts!!
in the future - u will be able to do some more stuff here,,,!! like pat catgirl- i mean um yeah... for now u can only see others's posts :c
GENERAL POLL
Do you think the latest video ' LIFE CYCLE OF GYMNOSPERMS' will be able to cross 100k views?
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And the second video to cross 100k+ views. None other than Life Cycle of Bryophytes. Thank you all for making it possible.
I hope this video is informative enough to clear all your doubts related to this topic.
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Animated videos for Physics? 1000 votes and I'll definitely consider !!!
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GENERAL CHARACTERS
* Gymnosperm is the group of Tall trees, the tallest being Sequoia reaching upto 120m in height.
* Gymnosperms are the first seed forming plant group i.e. First Tracheophytes.
* HABIT
* Gymnosperms mostly produces tall or medium size trees while a few species are found as woody shrubs.
* HABITAT
* Mostly found in temperate areas having high altitudes, some are found in tropical or sub-tropical regions.
* LIFE CYCLE
* Shows Diplontic life cycle
* BODY STRUCTURE
* The main body is the diploid Sporophyte which is well differentiated into roots, stem and leaves.
* STEM
* Woody i.e. Secondary growth is present
* Branched - Pinus, Cedrus
* Unbranched - Cycas
* ROOTS
* Tap roots.
* Pinus - Symbiotic (Mycorrhizal) association with Fungi
* Cycas - Coralloid roots - Symbiotic association with BGA (Anabaena cycadae)
* LEAVES
* Either Simple (Pinus) or Palmately compound (Cycas)
* Leaves are modified to withstand extreme conditions as
* Thin, needle like to reduce surface area
* REPRODUCTION
* Asexual reproduction and Vegetative propagation are absent in Gymnosperms.
* Sexual reproduction occurs by formation of gametes and spores.
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BREAD
* One of the common household product prepared by using microbes.
* The dough used for making bread is fermented using baker's yeast.
* Baker's yeast is a Fungi belonging to the class Ascomycetes and its scientific name is Saccharomyeces cerevisiae.
* Bread appears porous due to the formation of CO2 during Alcoholic fermentation by Saccharomyeces.
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SMOOTH MUSCLES
• Muscle fibres are spindle shaped or fusiform.
• Smooth muscles are unbranched.
• Striations are absent and hence they are called Smooth muscles.
• Smooth muscles are involuntary.
• Muscle contractions are slow.
• These muscles do not develop fatigue.
• Location: Present in viseral organs like gut, blood vessels and urinary bladder.
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CARDIAC MUSCLES
• Muscle fibres are cylindrical and branched.
• Intercalated discs are present at the junctions of cell.
• Striations are present but very faint.
• Cells are uninucleate.
• Cardiac muscles are involuntary.
• Performs slow and rhythmic contractions.
• Cardiac muscles never develop fatigue.
• Location: Myocardium of the heart.
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STRIATED MUSCLES
• Also known as Skeletal Muscles.
• Muscles fibres are cylindrical and unbranched.
• The fibres of skeletal muscles are arranged in bundles.
• Alternate light and dark bands called Striations are present.
• Fibres are multinucleate.
• Contractions are fast.
• Skeletal muscles are voluntary.
• Skeletal muscles get fatigued.
• Location: Most of the skeletal muscles are attached to the skeleton except the diaphragm and tongue muscles.
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GLANDS
* Glands are epithelial in origin
* Development of glands can occur from any of the 3 germ layers i.e Ectoderm, Mesoderm or Endoderm.
* Glands can be divided into different types based on number of cells, secretion and site of release.
APOCRINE GLANDS
* The secretion of first accumulates in the apical part of the cells and is later pinch off in the form of a vesicle.
* The size of the cell decreases due to secretion
* The cell regrows and again accumulates the secretions
* Examples: Sweat glands of armpits and thigh pits, Mammary glands
MEROCRINE GLANDS
* The secretions diffuses out of the cell
* The cells are not damaged during secretion
* Merocrine glands are also called Eccrine glands
* Examples: Salivary glands and sweat glands
HOLOCRINE GLANDS
* The entire cell disintegrates and releases the secretion out
* The secretions released are oily
* Example: Sebaceous glands
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* Cheese is one of the oldest food items obtained using microbes.
* There are wide range of cheese consumed in different parts of the world.
* Different varieties of cheese are known by their characteristic texture, flavour and taste.
* The specificity of cheese varieties comes from the microbes used during its preparation.
* Swiss cheese is prepared using a bacteria called Propionibacterium sharmanii and is characterized by presence of large holes.
* Roquefort cheese is prepared using a fungus called Penicillium roquefortii.
* Cheese can be prepared using cow milk, buffallo milk or even sheep milk.
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