CALORIFIC VALUES AND PEM

 






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WHAT ARE THE EVIDENCES FOR EVOLUTION? NEET (part-1)

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Nephron Vs Nephridium (Meta-nephidia & Proto-nephridia)

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  Nephrons  Each kidney has nearly one million complex tubular structures called nephrons (Figure 19.3), which are the functional units. Each nephron has two parts – the glomerulus and the renal tubule. Glomerulus is a tuft of capillaries formed bythe afferent arteriole – a fine branch of renal artery. Blood from the glomerulus is carried away by an efferent arteriole   The nephridium (plural nephridia) is an invertebrate organ, found in pairs and performing a function similar to the vertebrate kidney. Nephridia remove metabolic wastes from an animal's body. In addition to two basic categories ( metanephridia and protonephridia ), other types may exist. Metanephridia A metanephridium (meta = "after") is a type of excretory gland found in many types of invertebrates such as annelids, arthropods and mollusca. (In mollusca, it is known as the Bojanus organ.) A metanephridium typically consists of a ciliated funnel opening into the body cavity, or coelom connected to a duct...
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HUMAN REPRODUCTION

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 As you are aware, humans are sexually reproducing and viviparous.  The reproductive events in humans include  formation of gametes ( gametogenesis ), i.e., sperms in males and ovum in females,  transfer of sperms into the female genital tract ( insemination ) and  fusion of male and female gametes ( fertilisation ) leading to formation of zygote.  This is followed by formation and development of blastocyst and its attachment to the uterine wall ( implantation ),  embryonic development ( gestation ) and  delivery of the baby ( parturition ).  You have learnt that these reproductive events occur after puberty .  There are remarkable differences between the reproductive events in the male and in the female, for example, sperm formation continues even in old men, but formation of ovum ceases in women around the age of fifty years. 3.1 THE MALE REPRODUCTIVE SYSTEM   The male reproductive system is located in the pelvis region (Figure 3....
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