FUNDAMENTAL UNIT OF LIFE (PART II)

CLASS IX

Continuing with previous lecture on Cell: Fundamental Unit of Life for Class IX

This one covers #CellMembrane to develop a basis for study of transport across cell membrane.

Please follow carefully.

This video is followed by 4 more to develop an understanding of the types of transport across cell membrane.

Next we'll be doing some questions on the topics covered till now.

Understand, enquire & apply.

REPRODUCTION IN ORGANISMS PART II

In continuation with our previous discussion about introduction of first chapter, I'm uploading the second part.
In this part we'll be discussing Asexual reproduction: Modes & Significance.
Go through the video and try solving the assignments in between as well as at the end.

Class IX: Fundamental Unit Of Life (Part 1)

Welcome to Class 9.

Here is a lecture VDO for Chapter 5 of NCERT Class 9 Science Books.

Listen carefully and make notes based on the slides.

Happy Learning

Ask questions, clear doubts. Stay in touch

Reproduction In Organisms VDO Lecture

Covid 19 has put on hold many things. The one thing it need not derail is learning.

So here I'm uploading lecture for the first topic of #ClassXII Biology Lesson 1, Reproduction In Organisms.

Stay Connected & Keep Learning

RNA Interference

RNA interference in Unit IV of class 12 Biology is a concept that students find as difficult to grasp as teachers find it difficult to simplify. 
Though the basic concept is quite simple yet it becomes complex since some of the steps are beyond the grade level, and hence conveniently skipped in NCERT text books. with key steps missing you simply cannot grasp the concept.
So here is an easy to understand ppt, explaining the basic concept as well as required background knowledge.
Students can revisit these concepts.
Ask questions where you get stuck. consult your teachers. you may post queries here as well.
So here is the link for the ppt:
RNAi

and a few images

Meloidegyne incognita

Infected Root

Short Test ECOSYSTEM

Ecosystem

Try solving in 20 minutes

1. State the difference between the first trophic levels of detritus food chain and grazing food chain.
2. 8How does primary succession start in water and lead to the climax community? Explain.
3. Why are the pyramids referred to as 'upright' or 'inverted'? Give two examples of inverted pyramids.
4. Why are energy pyramid always erect?
5. Write the equation that helps in deriving the net primary productivity of an ecosystem. Differentiate between primary & secondary productivity.
6. Explain the simplified model of carbon cycle in nature.

Practice Paper: class XII

Lesson Covered:

Strategies for Improvement in Food Production
Microbes in Human Welfare
Biotechnology: Principles & Applications

Time: 1 ½ hour                                                                                                                       MM 40

Instructions:

Q 1-5 (1 mark), 6-10 (2 marks), 11-15 (3 marks), 16-17(5 marks)

1.       Name the first transgenic cow developed and state the improvement in the quality of the product produced by it.

2.       Name the vector used for transferring nematode specific gene in tobacco plant.

3.       What is SCP? Name the organism used for production of SCP.

4.       A resistant variety of Abelmoschus esculentus show resistance against a virus. Name the virus and plant variety.

5.       “A person is suffering with high blood cholesterol.” Which kind of bioactive molecule you will suggest to reduce his cholesterol level?

6.       A banana herb is virus infected. Name the method that will help in obtaining healthy banana plants from this diseases plant.

7.       Name the insect pest killed by the product of cryIAb gene. Explain how this gene makes the plant resistant to the insect pest.

8.       What is activated sludge? Where is it produced? Why is it named so?

9.       What is inbreeding depression. How can it be overcome?

10.   How are sugarcane varieties with high yield, thick stem, high sugar formed that can be grown in North India?

11.   Explain the term MOET. Which hormone is used for this method. Give the key steps of MOET.

12.   What are palindromes? Where are they used?

13.   What was Cohen & Boyer’s contribution to field of Biotechnology? Show diagrammatically.

14.   What is PCR? Where is it used. Represent the key steps diagrammatically.

15.   Draw a well labelled diagram of a cloning vector showing:

Ori, rop, atleast two restriction sites & 2 antibiotic markers. Give function of each.

16.   (a)Write any one drawback of selection of recombinant due to inactivation of antibiotic. Explain how recombinants and non-recombinants are differentiated on the basis of colour production in the presence of a chromogenic substrate?

     (b)Explain why DNA is not able to pass through cell membrane? Which methods are available to make the plant cell competent to take up DNA from surrounding medium?

17.   Given below is the   sketch of one method used to separate DNA fragments:

                

(a) Give the term caption for above diagram.

(b) At which end would be loaded the samples and why?

(c) Analyse the reason for different positions taken up by the DNA bands.

(d)Elaborate the step he would have followed to visualize DNA bands.

(e) Name the gel used in this technique.

VALUE POINTS: CLASS IX MIDTERM

Sequel to previous post.

marking scheme/value points for the sample paper uploaded earlier:

Q.1   A. Lysosome, B. Golgi Complex, C. Plastid / Mitochondria (any 2) ½×1

Q.2  Exosmosis                                                                                            1

Q.3  Conduction & Xylem                                                                           ½×1

Q.4  Striated/Skeletal Muscle                                                                    1

Q.5  In AIDS patients immune system is not working or weakened.    1

Q.6  Mycelium, Large number of spores                                                   ½×1

Q.7  A. Symptoms, b. acute & chronic, c. bacteria, infectious & defieicency ½×6

Q.8  Fungi, to kill bacteria

Q.9  A. Fungi (heterotrophic, cell wall chitin), Plantae (autotrophic, cell wall cytoplasm)              1×3

B. Monocot (single cotyledon, fibrous root, parallel venation), dicot ( 2 cotyledons, tap root, reticulate venation) – any 2           

C. Porifera (cell level of organisation, non motile), Coelentrata (tissue level of organisation, motile)

D. Piesces (aquatic, streamlined body, fins, gills), amphibians (both terrestrial & aquatic, not streamlined body, legs, lungs as well as gills) – any 2

OR

Whittaker’s 5 kingdom classification                                                                                                       3

Q.10                      3 differences between Prokaryotic & eukaryotic cells & diagram of both.                       5

OR

Parenchyma, Collenchyma & Sclerenchyma (2 differences & diagram)

Q.11                      Glycerine – to prevent from drying; Safranin – to stain                                                    1+1

Q.12                      Cockroach (jointed legs, segmented body, chitinous exoskeleton) – (any 2)    1+2

CLASS 9 MIDTERM QUESTION PAPER

Q.1  Name the cell organelle that:                         1/2×2                                                                                                       

a.       Protects cells from infections & toxins.

b.       Synthesizes complex sugars from glucose.  OR

c.       Contains DNA (other than nucleus)

Q.2   While cooking vegetables adding of salt causes the vegetables to release water, thus allowing vegetables to be cooked. Which process is responsible for release of water due to addition of salt?                      1

Q.3   A white flower was kept in red coloured water overnight. By morning the flower turned red. Which process & which tissue is responsible for the red colour of flower?                                                      1

Q.4   An athlete increases his speed as he closes on to the finishing line. Which muscles help him increase his running speed?                                                                                                                                         1

Q.5  Mucor infection in lungs leads to nasal congestion, wheezing throat irritation or coughing in healthy individuals. However, in AIDS patients it can be fatal. Why?                                                                          1

Q.6   2 characteristic behavioural features of fungi are: they are heterotrophic & they are non motile. What special structural characteristics have they developed to                                                                          1/2×2

a.       Obtain food

b.       Ensure survival

Q.7    Fill in the blanks:                                                                                                                                1/2×6

a.       Signs of disease such as fever, vomiting are known as its __________________

b.       Diseases that last for a short period are known as _____________, and those that persist for long periods are known as ________________

c.       Tuberculosis effects our lungs and is caused due to a ___________ while common cold causes cough is caused due to virus.

d.       Diseases caused due to microbes are known as ______________ disease, while diseases caused due to lack of essential nutrients in body are known as __________________ disease.

Q.8  Which organisms are the source of antibiotics? What is their use?                                                    1+1

Q.9  Differentiate (2 differences) between any 3 of the following groups of organisms:                               1×3

a.       Fungi & Plantae

b.       Monocotyledon & Dicotyledon

c.       Porifera & Coelentrata

d.       Pisces & Amphibia

OR

 What is the most popular method of classification of living organisms? Show with the help of flow chart? Name the scientist responsible for this classification.                                                                                  3

Q.10          You are asked to study cells from curd & plant leaf. What differences would you observe in the cells from these two sources (3 differences). Explain with the help of diagrams.                                       5

OR

Tabulate 2 differences between the three types of permanent tissues. Draw diagrams to show each type.

Section B

Q.11          Onion peel cells are kept in glycerine and treated with safranin before viewing under a microscope. Why are glycerine & safranin used?                                                                                                1

Q.12          Identify the organism & give its 2 distinctive features.                                 1+2