Q: Which of the following is not an endocrine gland?

\textbf{Correct option:D} \textbf{Solution:} \textbf{Option (A)} \bullet The endocrine part of the pancreas gland is an aggregation of cells known as islets of Langerhans which consists of four types of cells: alpha cells secretes glucagon, beta cells secretes insulin that regulates sugar metabolism ,delta cells produce somatostatin and f cells secretes pancreatic polypeptide that inhibits growth of tissue, secretion of pancreatic and gastric juice. \textbf{Option (B)} \bullet Adrenal gland is divided into two sections; adrenal cortex secretes aldosterone that helps in salt metabolism, cortisol that regulates sugar homeostasis and sex corticoids such as androgens and estrogens. Adrenal medulla secretes epinephrine and nor epinephrine that is secreted at the time of emergency. \textbf{Option (C)} \bullet Thyroid glands secrete thyroxine and triiodothyronine which increases metabolic rate of the body, prenatal brain development and regulates temperature in the body, another hormone thyrocalcitonin helps with the regulation of calcium metabolism. \textbf{Option (D)} \bullet There are three pairs of salivary glands parotid, sublingual and submandibular which secrete ptyalin (amylase enzyme that helps in initial carbohydrate breakdown . \textbf{Hence, the correct option is (D)}

Q: How many pairs of chromosomes are present in human beings? Out of these, how many are sex chromosomes? How many types of sex chromosomes are found in human beings? "The sex of a newborn child is a matter of chance and none of the parents may be considered responsible for it" Draw a flowchart showing the determination of the sex of a newborn to justify this statement.

\textbf{Solution:} \textbf{Part 1:} \bullet There are 23 pairs of chromosomes in cells of human beings. \textbf{Part 2:} \bullet Out of 23 pairs, 1 pair consists of sex chromosomes and 22 pairs are autosomes. \bullet There are two types of sex chromosomes X and Y chromosomes. \textbf{Part 3:} \bullet In humans, sex is determined on the basis of presence of sex chromosomes, X and Y chromosome. \bullet Male has X and Y chromosomes (XY), while the female has two X chromosomes (XX). \bullet The sperm has an X chromosome or Y chromosome while an egg has only X chromosome. \bullet After fertilization, if a zygote has XY chromosomes then it develops into male child whereas, if a zygote has XX chromosome then it develops into a female child.

Question 1

What are sex hormones? Why are they named so? State their functions.

Accepted Answer

Hormones which are secreted by testis in males and ovaries in females are called Sex Hormones. In males, it is testosterone and in females it is estrogen. They are named so because these hormones are responsible for the male and female secondary sexual characteristics. In females, the primary function of estrogen is the development of secondary sexual characteristics such as the development of breast, maturation of endometrium and regulation of the menstrual cycle. Whereas in males, it is testosterone that plays a key role in the development of male reproductive tissues such as prostate and testes and also promotes secondary sexual characteristics such as increased muscles and bone mass and growth of body hair.

Question 2

What are the secondary sexual characters in male and female?

Accepted Answer

Secondary sexual characters are those characters that are governed by the hormones released at the time of puberty, and usually is around two years earlier in females than man.The secondary sexual characteristics in males are :Hair growth on the face in the form of beard and moustacheThe growth of his testiclesHeavier musculatureAdam's apple developmentLarynx becomes larger results in a deeper voiceSome of the changes appear in females are:Development of breastLighter musculatureShrill and a higher pitch voiceBroadening of hips due to fat deposition

Question 3

Which of the following is not an endocrine gland?

Accepted Answer

extbf{Correct option:D}   	extbf{Solution:} 	extbf{Option (A)} \bullet  The endocrine part of the pancreas gland is an aggregation of cells known as islets of Langerhans which consists of four types of cells: alpha cells secretes glucagon, beta cells secretes insulin  that regulates sugar metabolism ,delta cells produce somatostatin and f cells secretes pancreatic polypeptide that inhibits growth of tissue, secretion of pancreatic and gastric juice. 	extbf{Option (B)} \bullet  Adrenal gland is divided into two sections; adrenal cortex secretes aldosterone that helps in salt metabolism, cortisol that regulates sugar homeostasis and sex corticoids such as androgens and estrogens. Adrenal medulla secretes epinephrine and nor epinephrine that is secreted at the time of emergency. 	extbf{Option (C)} \bullet  Thyroid glands secrete thyroxine and triiodothyronine which increases metabolic rate of the body, prenatal brain development and regulates temperature in the body, another hormone thyrocalcitonin helps with the regulation of calcium metabolism. 	extbf{Option (D)} \bullet  There are three pairs of salivary glands parotid, sublingual and submandibular which secrete ptyalin (amylase enzyme that helps in initial carbohydrate breakdown . 	extbf{Hence, the correct option is (D)}

Question 4

Reproductive age in women starts when their

Accepted Answer

Menstruation is the periodic discharge of blood and mucosal tissue from the inner lining of the uterus through the vagina. It begins with the onset of menarche at or before sexual maturity or puberty and stops at or near menopause.Development of breasts, height and weight increase are secondary sexual characteristics.

Question 5

How many pairs of chromosomes are present in human beings? Out of these, how many are sex chromosomes? How many types of sex chromosomes are found in human beings? "The sex of a newborn child is a matter of chance and none of the parents may be considered responsible for it" Draw a flowchart showing the determination of the sex of a newborn to justify this statement.

Accepted Answer

extbf{Solution:} 	extbf{Part 1:} \bullet  There are 23 pairs of chromosomes in cells of human beings. 	extbf{Part 2:} \bullet  Out of 23 pairs, 1 pair consists of sex chromosomes and 22 pairs are autosomes. \bullet  There are two types of sex chromosomes X and Y chromosomes. 	extbf{Part 3:} \bullet   In humans, sex is determined on the basis of presence of sex chromosomes, X and Y chromosome. \bullet  Male has X and Y chromosomes (XY), while the female has two X chromosomes (XX). \bullet  The sperm has an X chromosome or Y chromosome while an egg has only X chromosome. \bullet  After fertilization, if a zygote has XY chromosomes then it develops into male child whereas, if a zygote has XX chromosome then it develops into a female child.

Question 6

Choose the correct option.(a) Adolescents should be careful about what they eat, because(i) proper diet develops their brains.(ii) proper diet is needed for the rapid growth taking place in their body.(iii) adolescents feel hungry all the time.(iv) taste buds are well developed in teenagers.(b) Reproductive age in women starts when their(i) menstruation starts.(ii) breasts start developing.(iii) body weight increases.(iv) height increases.(c) The right meal for adolescents consists of(i) chips, noodles, coke.(ii) chapati, dal, vegetables.(iii) rice, noodles and burger.(iv) vegetable cutlets, chips and lemon drink.

Accepted Answer

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Question 7

Which of the following hormones controls metamorphosis in a frog?

Accepted Answer

Correct option: Correct option: This hormone regulates the metabolism of an organism and is also involved in the process of  metamorphosis showing the developmental changes in the life span of an organism.Hence, the correct answer is option (D)

Question 8

Write notes.(a) Adam's apple.(b) Secondary sexual characters.(c) Sex determination in the unborn baby.

Accepted Answer

(a) Adam's apple: The protruding part of 
the throat formed due to the enlargement of larynx is called as Adam’s apple. This enlargement of larynx or voice box occurs during puberty. Voice becomes hoarse.
(b) Secondary sexual characters:  Characters which usually appear during the phase of puberty are called as secondary sexual characters. These 
are the features that help in distinguishing the male and the 
female body from each other. Characters seen in male: Hoarseness of voice, appearance of beard, broadness of chest, growth of hair in genital areas.Characters seen in female: Start of menstrual cycle, growth of breast, growth of hair in the genital areas.(c) Sex determination in an unborn baby:
 Sex of a unborn baby depends upon the pair of sex chromosomes that are 
present in the cells of the baby. X and Y chromosomes are the sex chromosomes in humans. Ovum always contain X chromosome, male sperm may carry either X chromosome or Y chromosome. Male genetic make-up is 44 autosomes + XY chromosome and female genetic make-up is 44 autosomes  + XX chromosomes.

Question 9

"The sex of a newborn child is a matter of chance and none of the parents may be considered responsible for it." Justify this statement with the help of flow chart showing determination of sex of a newborn.

Accepted Answer

The hemizygous males produce two kinds of gametes, 1/2 gametes with X- and 1/2 with Y-chromosome (22 A + X and 22 A + Y). Fertilization of egg (22 + X) with sperm carrying 22+X chromosomes results in female child (44A + XX). Fertilization of egg (22 + X) with a sperm carrying 22+Y chromosomes results in a male child (44A + XY).  44 + XX (Female) 44 + XY (male)  22+X   22+X   22+X 44 + XX (Girl)44 + XX (Girl)  22+Y44 + XY(boy)44 + XY(boy)

Question 10

Adam's apple is a __________.

Accepted Answer

Adam's apple is the protruding part of the throat which is basically an enlarged voice box. It is larger in adult men.Thus, the correct answer is option (A) 'Large developed voice box in males'.