joint types- video

Plant growth regulators

Plant Growth Regulators by Nidhi gupta on Scribd

Meiosis animation

Mitosis animation

Cell cycle animation

Holiday Homework Assignment

DAV Public School, Kailash Hills

Holiday Homework (2017-18)

                                                                Class XI (Biology)

Based on your understanding of  The Living World, attempt the following questions:

Q1.What changes are needed to convert a prokaryotic cell into a eukaryotic cell?    

2. Give one distinct characteristic which separates human being from all other living organisms.

3. Ravi is a biology student. He visited a zoological park with his younger brother and in front of the lion enclosure they observed an information board with Panthera leo written on it. His brother was confused what it meant. What would Ravi explain to him?      

4. The common name of pea is simpler than its botanical name Pisum sativum. Why then is the simpler common name not used instead of the complex scientific name in biology? 

5. Suppose you accidentally find an old preserved permanent slide without a label. In your effort to identify it you placed the slide under microscope and observe the following features: 

a.Unicellular   b)well defined nucleus     c) biflagellate –one flagellum lying longitudinally and the other transversely.

What would you identify it as? Can you name the kingdom it belongs to?   

6. A virus is considered as a living organism and an obligate parasite when inside a host cell. But virus is not classified along with bacteria or fungi. What are the characteristics of virus that are similar to nonliving objects?                                                                               

7. Why is the spread of living pteridophytes limited and restricted to narrow geographical regions?                                                                              

8. Aniket visited Deer Park and found the lake there had green coloured water. What could be the green colour of water due to?                  

9. On rainy days you find green carpet like structure on the walls. Which plant group does it belong to? What are such plants commonly known as?                                            

10. Lichen is usually cited as an example of symbiosis in plants where an algal and fungal species live together for their mutual benefit. Which of the following will happen if algal and fungal partners are separated from one another?

a)      Both will survive normally and independent of each other.

b)      Both will die

c)      Algal component will survive while fungal component will die

d)     Fungal component will survive while algal component will die.

Based on your answer how do you justify this assosciation as symbiosis?                 

11. What is the importance of pneumatic bones and air sacs in Aves?                            

12. To which Phylum of Sand dollars, sea cucumbers and sea lilies belong to? What kind of symmetry do the adult representatives of this phylum have? Also mention what is specific     about their body cavity?                                                                                                             

13. Ksitij was watching discovery channel and he came to know about an animal which has a prominent head bearing large eyes and foot is modified partly into funnel and partly into 8-10 sucker bearing arms that surround the mouth. Identify the phylum to which this animal belongs and also one characteristic feature of the phylum.                                              

14. There is a group of animals commonly called as ‘animals with jointed feet’.They have bilateral symmetry, are triploblastic, have open circulatory system and malphigian tubules as excretory organs. Identify the phylum. Give an example of their fossil member representative.  

15. The young one of an animal looks different from the adult member. The body of both the young one and the adult can be divided in two equal halves. In young ones we can label the two halves as left and right one but we cannot do so in adult form.

a) Identify the phylum.

b) What kind of development is being shown?

c) What kind the symmetry is possessed by young one and the adult?                        

16. Hitesh’s mother purchased a plant from the gardener. The plant leaves had parallel venation, and the flowers of the plant were having beautiful purple petals. Harish observed each flower had precisely six petals without any mistake. He was surprised by the precision in nature and also was able to identify the group the plant belonged to? What conclusions could Hitesh have drawn about the plant classification and how?                                                         

Support material class Xi

Class xi biology support material

This book contains notes in nut shell. It is developed by Delhi government teachers under Department of Education.
  (It has some typing errors..You may correct the errors in this support material and may use it as helping notes)

You MUST study NCERT textbook thoroughly .