SOME IMPORTANT QUESTIONS (X) ..!!!!!

                                                   MCQ's 

           1) Four stages of binary fission in amoeba are shown below. This stage at which nuclear fission and 

              cytokineses are observed is ,stage   

 

(a) I                 (b) II                             (c) III                     (d) IV

2) To determine the percentage of water absorbed by the raisins, before final weighing of raisins after  being kept dipped in water for about two hours, extra water from the soaked raisins is removed by:

(a) dry cotton                 (b) filter paper            (c) hot air blower                     (d) silken cloth

1. 
   
   3) Out of the four slides I,II,III,IV whose details are shown below, which one would you focus under the microscope for observing budding in yeast?
   
   (a) I                          (b) II                       ( c) III                                   (d) IV
   
   
   4) The process represented in diagram below is the:
   
   (a) formation of spores in Amoeba
   (b) formation of bud taking place in Amoeba
   (c) identical gametes being formed in Amoeba
   (d) formation of daughter cells in Amoeba.
   
   
   5) A student soaked 5 grams of raisins in 25 mL of distilled water in each of two beakers A and B.  Beaker A was maintained at 25°C and beaker B at 50 °C. After one hour, the student observed that the water absorbed but the raisins was:
   (a) same in case of A and B                               (b) less in case of A than in B
   (c) exactly double in A, of that in B                    (d)exactly four times in A, of that in B
   
   
   6)A student was given two slides, one of the budding in yeast and the other of binary fission in amoeba. He was asked to identify any one difference in the nucleus of the two. He observed both the slides and identified correctly____
   (a) presence of two distinct nuclei in amoeba, one in yeast and two in bud.
   (b) presence of one nucleus in amoeba, two in yeast and one in its bud
   (c) presence of single nucleus each in amoeba and yeast cell and none in the attached bud.
   (d) presence of two nuclei in the centrally constricted amoeba, one in yeast cell and one in its bud.
   
   
                                  QUESTION/ANSWERS 
   Ques1: Select the biodegradable wastes from the following:
               DDT, Crop's residue, Leather and glass
   Ans: Crop's residue and leather 

 Ques2: In a food chain consisting snake, insect, grass and frog, assign an appropriate trophic level   to  frog.  Ans: Grass--> insect--> frog-->snake (Third Trophic Level)

  Ques3: Name those parts of a flower which serve the same function as the following do in animal:

                    (i) Testis (ii) Ovary (iii) Eggs (iv) Sperms  

                           Testis = Anther

                           Ovary = Ovary 

                           Eggs = Oules 

                           Sperms = Pollen ( Pollen Grains)  

  Ques4: What are fossil fuels? How are they formed?

   Ans:  Write the definition and formation of fossil fuels.

  

 Ques5: What is ozone? How does it protect the organisms on the Earth?

 Ans: Ozone is O_3. It forms a protective blanket over the earth's atmosphere and it's depletion causes harmful effects on humans. It absorbs the UV radiations coming from sun.

      

Ques6: What are sexually transmitted diseases? Name an STD which damages the immune system of  the human body?

Ans: Sexually transmitted diseases are diseases that spread through sexual contact.

               AIDS is the STD which damages the immune system of  the human body.

      

Ques7: Distinguish between analogous organs and homologous organs. Identify the analogous organs and homologous organs among the following:

Wings of an insect, wings of a bat, forelimbs of a frog, forelimbs of a human.

Ans: Homologous - organs having similar origin and structural plan but perform different functions.

        Analogous - organs having dissimilar origin and structural plan but perform same functions.

        Homologous organs: Forelimbs of frog and human

        Analogous organs: Wings of insect and bat.

Ques8:Study the given data and answer the questions that follow:

1	2	3
Parental plant cross fertilized and seeds collected	F1 Generation offsprings.	F2 Generation offspring after self pollination of F1 hybrid.

Male parent- Round Green seeds Female parent-Wrinkled Yellow seeds

All seeds- Round yellow

314-Round yellow 110-Round green 102-Wrinkled yellow 32-Wrinkled green

(a) What is the term given in this type of cross?

(b) What does the data in column 2 indicate?

State how did you arrive at this conclusion.

 Ans:  (a) Dihybrid Cross

          (b) Round shape and yellow colour in pea plants are dominant triats.

Ques9: What is the importance of DNA copying in reproduction? Why is variation beneficial to the species but not necessary for the individual? Explain.

Ans: DNA copying is essential part of reproduction because it ensures that same blue print of body design is maintained. Variation of the species is beneficial for adaptation and better survival. It may result in formation of blue species.

Ques10:(a) What is the role of seminal vesicles and the prostate gland?

              (b) What are the three categories of contraception methods? Write briefly about each.

Ans: (a)  Seminal vesicles-secrete the white substance which acts as lubricant , nutritive and    transport it. 

              Prostate gland- its secretion provides the medium for sperms to move.

        (b) 3 categories for contraception:

             Mechanical Barrier, Harmonal or Chemical Method , Surgical method.

Ques11: Draw longitudinal section of a flower and label on it following:

1. Ovary (ii) Style (ii) Stigma (iv) Anther

Why is vegetative propagation practised for growing some plants? Give two examples of plants grown by this method.

Ans:

 Vegetative propagation is used for growing some plants which do not produce viable seeds.

(give any two examples)