Ways by which housefly contaminate our food

Ways by which housefly contaminate our food
 1.the body of housefly especially its spiny legs pick up filth containing germs from dirty places.when such a fly sit on our food,it leave the germs on food and contaminate it.
2.housefly pour saliva on food.the saliva may have germs which contaminate our food.
3.housefly deposits its excreta while it sit or feeds on food.the excreta may have germs which contaminate our food

BY: ASHWANI KUMAR. BIO TEACHER PHAGWARA 9646388266

ADVANTAGE OF PROPAGATION OF ROSE BY BUDDING AND CUTTING

Advantage of propagation of rose  by cutting:
 1.It is an easy and quick method
2.it gives flowers similar to parent plant.
advantage of propagation of rose by budding:
1. in this method plant already have well established stem and roots therefore new branches grow faster  and flower soon.
 2.Same plant can be made to produce different coloured roses.Suppose buds  from yellow and white rose plant are grafted on red rose stem.in this case same plant will produce red yellow and white roses on different branches.

BY : ASHWANI KUMAR.BIO TEACHER AT VIGYAN TUTORIALS PATEL NAGAR PHAGWARA.9646388266

PRACTICE PAPER BIOLOGY +1

Time 3hrs
mm70
General instructions :- 1.all questions are compulsory.
2 the question paper consists of five sections A,B,C,D and E.sectionA consists of 5 questions of 1 mark each.sectionb is of 5 questions of 3 marks each,section C is of 1  questions of 3 marks whereas section D is of d questions of 5 marks each.section E is OTBA of 10marks (2 questions of 5 marks each) .
3.question number 20 is value based question.4.there is no overall choice.however,an internal choice has been provided in one question of 2 marks,one question of 3 marks and all the three questions of 5 marks weightage. A student has to attempt only one of the alternatives in such questions. 5.wherever necessary the diagrams drawn should be neat and properly labelled
                                                                    Section A
1.the cell wall of cells of a plant tissue shows the presence of hemicellulose and pectin.name the tissue.
2.name the scientist who proposed binomial nomenclature for organisms
3.the flow of impulses in a nerve is unidirectiona.give one reason.
4.state the function of heterocyst in nostoc
5.how is RNA differ from DNA in terms of nitrogenous base?
                                                                      section B
6.give the schematic representation of the steps of glycolysis/
7.what is the source of vasopressin hormone? Where is it stored?name the target organ of this hormone.state its function
8 given below are the pairs animals and their phylum from which they belong.which out of these is not a matching pair and why ?
 Unio -mollusca,culex - arthropoda ,pheretima - aschelminthes,fasciola - platyhelminthes
9.write names of four classes of fungi and the nature of mycelia present in them or both gymnosperms and angiosperms bear seeds,yet they are classified separatetely.give reason.
10.bile lacks enzymes yet it is essential for digestion.why?
                                                                    section c
11.what is symbiotic nitrogen fixation? Explain the role of leghaemoglobin and enzyme nitrogenase in atmospheric fixation
Answer the following :
1.name the stress hormone found in plants.2.write cause of bakane disease of rice.
13. A transverse section of a stem of a tree shows concentric rings.how are these rings formed? State the significance of ther rings
14. Describe the following as asked against each. 1.gizzard in cockroach : function 2.open vascular system : one example 3.heart name of tissue
15. Draw the basic structure of neural synapse and label the following parts in it : pre synaptic membrane, post synaptic membrane ,synaptic vesicles,neurotransmitter,

receptors,synaptic cleft

16.explain the mechanism of muscle contraction

17.why is mitosis called equational division? State any four points of difference between mitosis and meiosis.

18. Classify the plastids on the basis of type of pigments present in them and give their functions or give the scientific terms for the following processes a.loss of water from leaves through stomata in the form of water vapours.c.water absorbed by solids causing them to enormously increases in volume.

19.explain the mechanism of ascent of sap

.20.mohit, a 15 years old student thinks that smoking makes him more energetic.hence he tries to smoke when he is with his peer group.his friend rahul advises him to avoid smoking. A.which respiratory disorder is caused by cigarette smoking? B.Give adverse effect of this disorder.c.write any two values used by rahul in counselling his friend.

21.how are proteins formed? Describe the primary,secondary and tertiary structure of proteins/

                                                                  or 

a. Which cell organelle is also called as power house of cell. b.describe its structure with labelled diagram.c.how do these cell organelles reproduce?

22. A.what is photophosphorylation?

 B.where do this mechanism occur in plant cells ? 

C.explain the process of cyclic photophosphorylation 

                                                                or

A. Where does electron transport system operative in mitochondria? Explain the system giving the role of oxygen. 

B.what is oxidative phosphorylation ? 

23.how do arteries and veins differ in regard to 1.presence of semilunar valves 2.presence of blood. B.explain the different segments in a standard  ECG

 

                                                                or.
A.explain the role of loop of henle in urine formation in humans.
 B. Draw the labelled diagram of nephron /
                                                        section E (OTBA)
24. The stress  of modern day living is causing an enormous burden on health care globally.comment upon the problem arising due to this stress and suggest possible solutions
25.can one lead a healthy life without compromising his contribution towards growth and development of the organization and the nation at large ? Explain.

BY: ASHWANI KUMAR @VIGYAN TUTOTIARLS. PATEL NAGAR OPP ANOOP  HOSPITAL PHAGWARA 9646388266

INTERESTING FACTS IN BIOLOGY

1.Mature red blood cells of all mammals lack nuclei,with the exception of those in the camel
2.most roots are positively geotropic but roots of mangrove plants grow away from gravity
the aquatic larval stage of American salamander can reproduce inspite of retaining its larval form
3 DNA is the hereditary material with the exception of some viruses such as tobacco mosaic virus TMV
 4. A human being is clinically dead when there is no pulse that is no heart beat and his pupils are fixed and dilated ( no reaction to light).clinical death is not the same as biological death. Almost all the body cells remain alive for several hours after clinical death.this is why tissues and organs to be used for transplantation are removed within a few minutes after death
5.ciliates hitherto thought tobe immortal due their capacity for binary fission, are now found to age and die ,after a certain number of fissions
6. an amoeba divides into two cells, which in turn divide into two each and so on.when does an amoeba dhe? Bacteria divide every 15 to 20 minutes,the original losing its identity.when there is overcrowding ,bacterial cells die as a result of their own secretions. We can call this natural death
7/resurrection plants : some species of moss Selaginella grow on exposed rocks and have ability to survive dessication.when placed in water they revive and are hence called resurrection plants. Myrothamnus and craterostigma grow in highly arid regions of south Africa.dark brown dried up plants when receive rain the plants revive,their leaves  become green and functional .in extreme dessication these plants appear dead but come to life when water is available.
By: ashwani kumar @vigyan tutorials. phagwara. 9646388266

ALEXANDER FLEMING & DISCOVERY OF PENICILLIN

Alexander Fleming (1881-1955) was studying the bacterium Staphylococcus that causes throat infection.he was growing this organism in petri plates on agar medium.it is a common observation that such culture media often get contaminated with other microbes.fleming observed contamination of a blue -green mould Penicillium notatum, in one of his culture plates.normally contaminated cultures are discarded but fleming retained this particular plate.it looked different ,as the normal cloudy aqearance resulting from bacterial growth was absent.the presence of a clear area round the mould indicated that bacterial growth had been inhibited.many other bacteriologists had also made the observation that moulds inhibit bacterial growth.but fleming wanted to know why.further investigation led to the discovery that toxic substance produced by the mould inhibited bacterial growth.fleming named this substance penicillin (1928-29).he made the cautious statement that penicillin might prove to be an effective antiseptic agent against  penicilin sensitive microbes.subsequently tests showed that penicillin was not toxic to human beings and thus it became one of the most useful antibiotics.during world war 2, penicillin proved to be of tremendous value in controlling infections among wounded soldiers.

by: ashwani kumar @Vigyan Tutorials ,patel nagar. opp anoop hospital, phagwara

INTERESTING FACTS IN BIOLOGY

1.Eucalyptus regnans is the world's tallest tree with recorded height of 375 ft .this is closely followed by californian coast redwood - Sequoia sernpervirens which is 366 ft tall2.blue whale is the largest animal ever existed on earth.it can reach to length of 30m
3.in plant Amorphophallus which is found in Sumatra the inflorescence ( flower bearing axis) can be 5.5 m long.
4.smallest plant is wolffia arrhiza.it resembles small green dots or grains floating in water
5.Rafflesia is world's largest flower with diameter of about one meter and 2.5 cm thick petals
6.an insect called cicada has life span of about 17 years.it emerges from ground and remaim awake for about  weeks and then dies/
7Acetabularia is a single celled alga with length of about 6-10cm
8 the male baya or weaver bird makes beauiful nest with grasses.the females visit the nest of different male birds and select only that male whose nest they like the most.sometimes to impress females the male birds decorate their nests with colourful petals/
9.total length of blood vessels in our body is about 96000km
10.who have more body hair- human or ape? Its human.human have more body hair than apes but human hair are shorter and softer
11.internal area of human lungs is about 93suare m etre which is about  40 times the area of human body/fastest nerve impulse can travel at speed of about 532kph.

By: Ashwani Kumar @Vigyan Tutorials.patel nagar.phagwara.9646388266

03 : CARBON CYCLE