What is 'Water Diabetis' and how it is caused?

Water Diabetis is technically known as Diabetis insipidus (insipid means tasteless). This defect in a person is caused due to hypo or under secretion of ADH or Vasopressin hormone released by Posterior lobe of pituitary gland. Normal secretion of this hormone will help the kidney tubules to retain correct amount of water and the urination process is normal. Due to under secretion of this hormone, kidney tubules collect excess water from the blood . So the patient show frequent and copious  urination which leads to more loss of water along with the urination. The patient of this defect feels thirsty and dehydrated.

Why millions of sperms produced in male even though one sperm is enough to fertilize an egg?

Large number of sperms have to travel a long distance from the region of cervix to oviduct or fallopian tube before they meet the egg in the female genital tract. The life span of a sperm is about 24-48 hours after their deposition at cervix in the vaginal canal. During the course of their travel to reach the egg in oviduct many of the sperms die on their way.  During their travel they have to over come the acidic conditions of female genital tract to reach and surround the egg. So, a few of the sperms only successfully reach the egg and out of which one of the active sperm  only fertilize the egg.   

In rare cases, why we see some women are with beard and some men are with breasts ?

This condition can be seen due to overgrowth of Adrenal cortex in male and female .  Adrenal cortex is the outer region of Adrenal gland which secrete sex corticoid hormones (both male and female hormones in an individual). These hormones are similar to male and female hormones secreted by Testis and ovaries. Due to overgrowth of Adrenal cortex in female, male hormones produced in excess will influence the development of mustache, beard  and deep voice in her. Such condition which is caused through overgrowth of Adrenal cortex in females is known as Adrenal virilism (Latin: virilism=maleness). In the case of male, if overgrowth of Adrenal cortex occur, female hormones produced in excess will cause the development of feminine features like development of breast in man.

Why Simple Goiter is more prevalent in hilly plains and cannot be found in coastal areas?

Simple goiter is caused due to under secretion or hypo secretion of  Thyroxin hormone by Thyroid gland. The mineral iodine is essential for the synthesis of Thyroxin by our thyroid gland. In hilly plains, the iodine content will be washed away through leaching from slopes of the hills during precipitation of rains. Due this vegetables and grains obtained from the crops lack iodine which cause goiter disease. But in coastal regions, the sea food contain iodine in sufficient quantity and so this problem cannot be seen in these places.  

Testis are originally abdominal in a baby while it is in the mother's womb but become extra abdominal just before the time of birth?

Up to seven months of the baby development in the mother's womb, testis are present inside the abdomen. But just before the time of birth, testis descend down into scrotal sacs which lie externally below the abdomen. The reason for this is, testis cannot produce motile sperms if they are subjected to our normal body temperature. To reduce their temperature to 2 to 3 degrees centigrade below our body temperature, they were kept away from our body in scrotal sacs.

Why insulin hormone cannot be given orally but has to be given intravenously?  

Insulin hormone is a protein. So if a protein is taken orally, it will be digested and broken down into simple units like a normal protein. The chemical nature of this hormone will be lost before it reaches the target organ to do its activity. Hence this hormone should not be taken orally. If insulin hormone is given intravenously, it travel along with blood circulation and reach the target organ without loosing its chemical structure to start its function.

Is Sunflower an Inflorescence or a simple flower?

Sunflower is an inflorescence. Even though the flower appears to be a single flower but it formed of so many floral units or small flowers called 'florets'.  The florets present in Sunflower are of two kinds- (a) Disc florets present at the center of the flower and (b) Ray florets present at the periphery of the flower. The disc florets are bisexual in nature whereas ray florets are unisexual or female or sometimes neutral in nature. In this inflorescence the peduncle is highly condensed to form a disc shaped receptacle on which the florets are arranged  in a centripetal (develops from periphery to inwards)  fashion. This type of inflorescence is known as Heterogamous Head or Capitulum or Anthodium inflorescence. This inflorescence is most commonly found in Asteraceae family. The scientific name of Sunflower is Helianthus annus.