CBSE ADDA

(I) answer the following questions in one word 1. What is the age of puberty in girl? Ans: 10 – 12 years 2. Which gland secretes Corticoid hormones? Ans: Adrenal Glands 3. What types of fertilization takes place in Man? Ans: Internal Fertilization 4. What is the other name of Endocrine garland? Ans; Ductless gland 5. What is the term used for development of Ovum without fertilization? Ans: Parthenogenesis 6. Name the hormones secreted by pineal glands? Ans: Melatonin 7. Which gland is called master glands? Ans: Pituitary Gland 8. When chromosome is not sex chromosomes, what is it called? Ans: autosomes 9. Name the term used for having X and Y chromosomes. Ans: Sperm gamete 10. Name the hormones secreted by testes? Ans: Testosterone (II) Answer the following questions in brief 1. Why does our body changes when we reach to teens? Ans: when we reach to teens, Endocrine system of or body regulate the release of hormo

1. Which animal tissue is commonly known as packaging tissue? [1] Ans: Areolar Tissue 2. What do you mean by photoperiod? Name two processes that are dependent on photoperiod.[2] Ans: Photoperiod is related to exposure of plants to the duration of sunlight. Germination, growth and flowering (any two) in case of plants are dependent on Photoperiod. 3. What will happen if:  i) the skin epithelium is not stratified.  ii) Stratified squamous epithelium lines blood vessels. [2] Ans: i) There will be no protection to the inner layers and wear and tear will be more.        ii) The exchange of substances through selectively permeable surface cannot take place. 4. Name the target organ/organ system of AIDS virus. What is the cause of death in case of people suffering from AIDS? [2] Ans: Lymph nodes/Immune System. In absence of a strong Immune system ,minor infections can turn in to serious problems. 5.To increase productivity per unit area ,the farmers grow two differe

Chapter – 3 ATOMS AND MOLECULES  1.  An old man and a scientist were talking about a deserted house. The old man was sure that it was haunted by ghosts, but the scientist discarded the view saying no one had ever seen a ghost. The old man was annoyed and challenged the scientist about existence of atoms, sub-atomic particles which also could not be seen. · Name the three sub-atomic particles and their discoverers. · Whose viewpoint do you support and why? 2.  An activity was conducted in a classroom where students held placards with symbols and valency of the elements separately. Each student held two placards, one with the symbol in the right hand and other with the valency in the left hand. · Which placards will be required for formation of sodium chloride ( both symbol as well as valency). · Which qualities are required in the student to perform such a group activity? 3.  Two class IX students, Kaveri and Nalin, were asked to take 5.3 g of sodium carbonate and 6g

CBSE-CH: Floatation GRAVITATION]                              Q1.While passing nearby a pond, some students saw a drowning man screaming forhelp. They alerted another passerby, who immediately threw an inflated rubber tube in the pond. The man was saved.· Why the passerby did use inflated rubber tube to save the  drowning man? ·Write the principle involved here.· Which qualities shown by the students and the passerby do you identify that helped in saving the drowning man? Q2.You received  an e-mail from  a friend living in  a coastal town. He shared an experience with you that recently, while swimming on the coastline of the sea in common swimming attire, he thought of going deeper inside the sea. He was asked to abstain from delving deeper into the sea by the rescue personnel. Respond  to the following questions using the information provided above.Why the rescue personnel asked your friend not to swim deeper inside the sea? · What values were exhibited by the rescue personne