Skip to main content

8th science Ch10 Reaching the age of adolescence solved questions

CBSE Science Chapter 10  Reaching the age of adolescence study help by JSUNIL sir
Q1. What is adolescence?

Ans. It is the period of life when the body undergoes changes, leading to reproductive maturity.

Q2. Define puberty.

Ans. The stage when human body becomes sexually mature.

Q3.  What is adam’s apple?

Ans. The growing voice box in boys can be seen as a protruding part of the throat called adam’s apple.

Q4. What are secondary sexual characters?

Ans.These are the features that help to distinguish males from females.

Q5. Define the following terms. (a) Hormone (b) Endocrine glands

Ans. (a) Hormone- they are chemical messengers for various processes and activities in the body
        (b) Endocrine glands- the ductless glands which secrete hormones directly into blood.

Q6. Enlist the changes occurring in males and females during puberty.

Ans.
Type of change
In girls
In boys
Increase in height
Sudden increase
Sudden in crease
Body shape
Waist widens
Shoulders broadens
Voice change
High pitched
Voice becomes deeper
Development of sex organs
Ovaries mature and releases eggs.
Testes matures and produces sperms


Q7. What is the role of hormones in initiating reproductive function?

Ans.1. Hormones from pituitary stimulate testes and ovaries to release testosterone and  estrogen  respectively.

3. These sex hormones reach to target sites via blood.

4. Then stimulate changes in the body at the onset of puberty.

Q8.  Discuss reproductive phase of life in women.

Ans. In females the reproductive phase of life begins at puberty and continues till they reach the age of 45-50 years. The egg begins to mature with the onset of puberty. One mature ovum is released by one of the  ovaries every month. The process is called ovulation. During this period, the walls of the uterus become thick  so as to receive fertilized egg.  Then this egg gets implanted in the uterus resulting in pregnancy.

Q9 Give reasons for the following :

a. Tadpoles growing in iodine deficient water have retarded growth.

Ans. The process of growth and development is regulated by thyroxine hormone which is produced by thyroid gland. Iodine is required for thyroxine production. That is why retarded growth is seen in tadpoles living in iodine deficient water.

b. Voice becomes hoarse in adolescent boys.

Ans. Sometimes the muscles of the growing voice box go out of control and the voice becomes hoarse.

c. Adolescents experience acne and pimples.

Ans. This is dues to increased activity of sebaceous (oil) glands in the skin.

d. Females have no role in determining gender of a child.

Ans. Y- chromosomes that leads to a boy offspring is contributed by male parent. That is thesperms are of two types, having either X or Y chromosome.

10. What are the causes of AIDS?

Ans. The causes of AIDS are:
1. Sharing needle of the syringe            
2. unprotected sex with infected person.        
3. blood transfusion from infected person to healthy one.
4. infected mother can pass HIV through milk to an infant.
8th Chapter: Reaching the Age of Adolescence
Science Mission class8 Chp10 Reaching the Age of Adolescence  
Download solution
CBSE Solved Questions Paper-1
CBSE Solved Questions Paper-2
CBSE Solved Questions Paper- 3
CBSE Solved Questions Paper- 4
VIII  Reproduction in Animals    
Reproduction in Animals  [E-NOTES]
CBSE Test Paper  [solved question]
CBSE Worksheet for practice
Reproduction & Endocrine [solved]

Comments

  1. Chapter 10- Reaching the age of Adolescence
    Answer the following questions
    1. Name the hormone produced when one is very angry or worried.
    2. The chemicals secreted by endocrine gland are called _________.
    3. How many pairs of chromosomes are found in the nuclei of their cell?
    4. Why endocrine glands are termed ductless glands?
    5. Name the disease caused due to lack of insulin producation.
    6. Name the hormone that controls metamorphosis in a frog. Name the mineral required by this hormone.
    7. Name the gland which controls the activity of other endocrine glands.
    8. Name the hormone which maintains the correct salt balance in the blood.
    9. Name three glands which release their secretions through ducks.
    10. Name the hormone produced by thyroid gland and the disease caused due to lack of its producation.
    My jsuniltutorial offers CBSE Board course material free of cost Pls. use it and share to student

    ReplyDelete

Post a Comment

CBSE ADDA :By Jsunil Sir : Your Ultimate Destination for CBSE Exam Preparation and Academic Insights

Class 10 Chapter 02 Acid Bases and Salts NCERT Activity Explanation

NCERT Activity Chapter 02 Acid Bases and Salt Class 10 Chemistry Activity 2.1 Indicator Acid Base Red litmus No Change Blue Blue Litmus Red No change Phenolphthalein Colourless Pink Methyl Orange Pink   Yellow Indictors are substance which change colour in acidic or basic media. Activity 2.2 There are some substances whose odour changes in in acidic or basic media. These are called olfactory indicators. Like onion vanilla, onion and clove. These changes smell in basic solution. Activity 2.3 Take about 5 mL of dilute sulphuric acid in a test tube and add few pieces of zinc granules to it. => You will observe bubbles of hydrogen gas on the surface of zinc granules. Zn + H2SO4 --> ZnSO4 + H2 => Pass the Hydrogen gas through the soap solution. Bubbles formed in the soap solution as Hydrogen gas it does not get dissolved in it

Living science ratna sagar class 6 solutions

Ratna sagar living science 6 answers by jsunil. Class6 Living science solution Term-1 Living Science Solution chapter-1 Source of food Download File Living Science Solution chapter-2 Component of food Download File Living Science Solution chapter-3 Fibre to fabric Download File Living Science Sol ch-4 Sorting of material into group Download File Living Science Soln ch-5 Separation of substance Download File Living Science Solution chapter-6 Change around Us Download File Living Science Solution ch-7 Living and Non Living Download File Living Science Solution ch-8 Getting to Know Plants Download File Living Science Sol ch-9 The Body and Its movements Download File Visit given link for full answer Class6 Living science solution Term-II

Class 10 Metal and Non MetalsChapter 03 NCERT Activity Solutions

X Class 10 NCERT Activity Explanation Class 10 Metals and Non Metals Activity 3.1 Page No. 37 Take samples of iron, copper, aluminium and magnesium. Note the appearance of each sample. They have a shining surface. Clean the surface of each sample by rubbing them with sand paper and note their appearance again. They become more shiny. => Freshly cut Metal have shiny surface Activity 3.2 Page No. 37 Take small pieces of iron, copper, aluminium, and magnesium. Try to cut these metals with a sharp knife and note your observations. They are very hard to cut. Hold a piece of sodium metal with a pair of tongs and try to cut it with a knife. Sodium can be cut easily with knife. Hence K and Na are soft metal cut with knife Activity 3.3 Page No. 38 Take pieces of iron, zinc, lead and copper try to strike it four or five times with a hammer. These metals are beaten into thin sheet on hammering. This property of metal is called malleability and metals are called malleable. Activity 3.4 Page

CBSE I NCERT 10th Numerical Problem solved Reflection and reflection of light

Q. 1. A concave mirror of focal length 20cm is placed 50 cm from a wall. How far from the wall an object be placed to form its real image on the wall?  Solution: V= -50 cm F= -20cm From mirror formula 1/u = 1/f – 1/v = -1/20+ 1/50 = - 3/100  U = - 33.3 cm Therefore, the distance of the object from the wall x =  50 – u X = 50 – 33.3 = 16.7 cm. Q.2. An object is placed at a distance of 40cm from a concave mirror of focal length 15cm. If the object is displaced through a distance of 20 cm towards the mirror, By how much distance is the image displaced? Answer: Here f = - 15 cm, u = - 40 cm Now 1/f = 1/u + 1/v Then 1/v = 1/f – 1/u Or V= uf/u-f =( - 40 x -15)/25 = -24 cm Then object is displaced towards the mirror let u1 be the distance object from the Mirror in its new position. Then u1 = -(40-20) = -20cm If the image is formed at a distance u1 from the mirror then v1 = u1f/u1-f = -20X-15/-20+15 = -60 cm. = - 20 x-15/-20+15 = -60 cm. Therefor

Electricity numerical for class 10 CBSE Trend Setter 50 Problems

1. The current passing through a room heater has been halved. What will happen to the heat produced by it? 2. An electric iron of resistance 20 ohm draws a current of 5 amperes. Calculate the heat produced in 30 seconds. 3. An electric heater of resistance 8 ohm takes a current of 15 A from the mains supply line. Calculate the rate at which heat is developed in the heater. 4. A resistance of 40 ohms and one of 60 ohms are arranged in series across 220 volt supply. Find the heat in joules produced by this combination in half a minute. 5. A resistance of 25 ohm is connected to a 12 V battery. Calculate the heat energy in joules generated per minute. 6. 100 joules of heat is produced per second in a 4 ohm resistor. What is the potential difference across the resistor? 7. An electric iron is connected to the mains power supply of 220 V. When the electric iron is adjusted at minimum heating’ it consumes a power of 360 W but at ‘maximum heating’ it takes a power of 840 W. Ca