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What are antibodies and antigens??

Posted by Harshvardhan Sharma 7 years, 2 months ago

1 answers

Yogita Ingle 7 years, 2 months ago

Antigens are substances that stimulate the immune system to produce antibodies. Each antigen has a distinct surface feature or epitope. Thus there is a resultant effect of a specific response. Antigens could be anything like a pathogen or bacteria or fungi or even virus. They cause diseases or allergic reactions.
An antibody is an immunoglobulin. It is a Y shaped molecule which is basically a protein that is produced by the B cells of the immune system. Antibodies are produced in response to the exposure to antigens.

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How ovary fertilise by sperm

Posted by Alexa Runaleas 7 years, 2 months ago

CBSE > Class 12 > Biology

2 answers

Anjali Yadav 7 years, 2 months ago

Firstly your question is not appropriate Ovum is fertilised by sperm Answer=sperm on interaction with cells of corona radiata it release enzyme hyalohynase by Acrosome and induce some changes that prevent polyspermy Single sperm fuse with ovum and form zygote

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Harshvardhan Sharma 7 years, 2 months ago

The process of fertilization involves a sperm fusing with an ovum. The most common sequence begins with ejaculation during copulation, follows with ovulation, and finishes with fertilization. Various exceptions to this sequence are possible, including artificial insemination, in vitro fertilization, external ejaculation without copulation, or copulation shortly after ovulation.Upon encountering the secondary oocyte, the acrosome of the sperm produces enzymes which allow it to burrow through the outer jelly coat of the egg. The sperm plasma, then fuses with the egg's plasma membrane, the sperm head disconnects from its flagellum and the egg travels down the Fallopian tube to reach the uterus.

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2019 Practical And Board Examintions Time Table

Posted by Siranjeevi Kumar 7 years, 2 months ago

CBSE > Class 12 > Biology

1 answers

Alexa Runaleas 7 years, 2 months ago

Really you dont know

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Give significance of transgenic plants and animals?

Posted by Aziz Ekbal 7 years, 2 months ago

CBSE > Class 12 > Biology

1 answers

Hy Shona 7 years, 2 months ago

They help us to study about diseseas,some disorders and thus we van find the treatment for it.

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New ncert published hui h na to usme jo kuch new print hua h wo send ker dijye

Posted by Shubham Verma 7 years, 2 months ago

CBSE > Class 12 > Biology

1 answers

Hy Shona 7 years, 2 months ago

Pta nhi yarr

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differentiat between chemical and biological origin of life.

Posted by Chiranjib Kalita 7 years, 2 months ago

CBSE > Class 12 > Biology

0 answers

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There has been some changes in NCERT biology class 12 in 2018 . Will the questions in 2019 board exam be requiring answer according to changes made or can we write answer according to old NCERT (latest edition but changes has not been made in that)?

Posted by Ankit Singh 7 years, 2 months ago

CBSE > Class 12 > Biology

0 answers

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There has been some changes in NCERT biology class 12 in 2018 . Will the questions in 2019 be requiring answer according to changes made or can we write answer according to old NCERT (latest edition but changes has not been made in that)?

Posted by Ankit Singh 7 years, 2 months ago

CBSE > Class 12 > Biology

0 answers

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Do we have value based question for 2018-2019 batch?

Posted by Berjith Berjith 7 years, 2 months ago

CBSE > Class 12 > Biology

3 answers

Shreya Bhardwaaj 7 years, 2 months ago

No its not there but one topic is added

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Mohit Sepat 7 years, 2 months ago

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Divya Pratap Singh 7 years, 2 months ago

As far as i know they are not from this session i.e from 2018-19 session.

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How do pills act as contraceptive in human female?

Posted by Abhijeet Baglari 7 years, 2 months ago

CBSE > Class 12 > Biology

2 answers

Anjali Yadav 7 years, 2 months ago

By thickening of cervical mucus that prevent entry of sperm And also make uterus unsuitable for implantation

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Kavi Mishra 7 years, 2 months ago

They supress the release of hormones like progestrone and FSH, which in turn prevents the release of the ovum from grafian follicle and hence prevents fertilization....

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A person is born with a heridity disease , suggest the possible charactive method of it

Posted by Tanu Jadoun 7 years, 2 months ago

CBSE > Class 12 > Biology

0 answers

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Mendal law

Posted by Nitish Kumar 7 years, 2 months ago

CBSE > Class 12 > Biology

2 answers

Hy Shona 7 years, 2 months ago

Second law-Law of Segregation-thia law states that alleles do not show blending they recovered themselves in F2 generation. Third law-Law of IndependentAssortment-the law states when two pairs of traits are combined in a hybrid ,segregation of one pair of character is independent of the other pair of character.

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Hy Shona 7 years, 2 months ago

First law- Law of dominance-1)Characters are controlled by discrete units called factors. 2)Factors occur in pairs. 3)In a dissimilar pair of factors one member of the pair dominates and the other is reccessive.

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What is aminoacylation? State its significance.

Posted by Brahmjot Kaur 7 years, 2 months ago

CBSE > Class 12 > Biology

2 answers

Hy Shona 7 years, 2 months ago

Amino acids formed during translation need to join through peptide bond and this process need energy . Therefore through aminoacylation trna is charged and when two charge trna brought closer then they favour to form peptide bonds .

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Hy Shona 7 years, 2 months ago

Amino acid are activated ihe presence of ATP and linked to their cognate trna -a process commonly called charging of trna and this process is also known as aminoacylation of trna.

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What is kyotoprotocol

Posted by Senthil Raja 7 years, 2 months ago

CBSE > Class 12 > Biology

0 answers

ANSWER

How and why is the bacterium 'Thermus aquaticus' useful in R-DNA technology?

Posted by Brahmjot Kaur 7 years, 2 months ago

CBSE > Class 12 > Biology

1 answers

Hy Shona 7 years, 2 months ago

Thermostable DNA polymerase enzyme is needed to make DNA thermostable as it could tolerate high temperature .And this enzyme is isolated from a bacterium,Thermus aquaticus.

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State the role of deoxyribonucleoside triphosphate during DNA replication

Posted by Srishti Keshwani 7 years, 2 months ago

CBSE > Class 12 > Biology

1 answers

Brahmjot Kaur 7 years, 2 months ago

Deoxyribonucleoside triphosphate serve dual purposes. In addition to acting as substrates, they provide energy for terminal phosphates, in a deoxynucleoside triphosphates, are high energy phosphates, same as in case of ATP.

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Which sample paper is best for biology class 12

Posted by Stuti Mehra 7 years, 2 months ago

CBSE > Class 12 > Biology

1 answers

Pranjal Sehrawat 7 years, 2 months ago

Arihant... 10 year

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Explain.. Female reproductive part?

Posted by Ishi Sharna 7 years, 2 months ago

CBSE > Class 12 > Biology

5 answers

Hy Shona 7 years, 2 months ago

And somil why have thanks for what my friend.

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Hy Shona 7 years, 2 months ago

I cann't understand your question.

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Pranjal Sehrawat 7 years, 2 months ago

Terko smjh ni aaye......

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Somil Singh 7 years, 2 months ago

Primary *** organ that is ovaries

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Somil Singh 7 years, 2 months ago

Puchna kya chahti hai

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Out of many papaya growing in your garden only a few bear fruits. Give reason.

Posted by Brahmjot Kaur 7 years, 2 months ago

CBSE > Class 12 > Biology

1 answers

Hy Shona 7 years, 2 months ago

Because others are male plant and because only plant bearing female flower means have female reproductive parts bears fruits hence some plants have fruits but others do not. I hope my answer is satisfied mr.kaur bhai.

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What will happen if DNA replication is not followed by cell division in eukaryotic cell?

Posted by Brahmjot Kaur 7 years, 2 months ago

CBSE > Class 12 > Biology

3 answers

Hy Shona 7 years, 2 months ago

Thanks shubham at least anybody answer.

1Thank You

Shubham Sharma 7 years, 2 months ago

No the answer is wrong Correct ans is it will lead to multinuclear condition that is. Known as syncitium condition

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Hy Shona 7 years, 2 months ago

If dna replication do not occur than the dived cell do not have genetic material.

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Give one example of analogy and homology in plants

Posted by Abhijeet Baglari 7 years, 2 months ago

CBSE > Class 12 > Biology

1 answers

Brahmjot Kaur 7 years, 2 months ago

HOMOLOGY :- The fore-limbs of man, cheetah, whale and bat have the same basic structural plan. But the fore-limbs of thees animals have different shapes and functions. In man they are used for grasping, in cheetah for running, in whale for swimming and in bat for flying. ANALOGY :- The wings of an insect are analogous to wings of a bird. It is due to the fact that the basic structure of the wings of the insects is different from the wings of bird. However, their function is similar.

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Is aminoacylation differ from charging of tRNA? If yes/no then why?

Posted by Brahmjot Kaur 7 years, 2 months ago

CBSE > Class 12 > Biology

1 answers

Hy Shona 7 years, 2 months ago

No I think both are same.

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List three biological ways to control pest and disease in agricultural management.

Posted by Kalpna B. K. 7 years, 2 months ago

CBSE > Class 12 > Biology

1 answers

Hy Shona 7 years, 2 months ago

Organic farming,gene therapy and pest resistant plant

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Differentiate between sickle cell anaemia and thalassemia in tabular form .

Posted by Deepika Gaur 7 years, 2 months ago

CBSE > Class 12 > Biology

1 answers

Hy Shona 7 years, 2 months ago

Sickel cell anaemia-1)this defect is caused by the substitution of Glutamic acid by valine at the 6th position of yhe beta globin chain of the haemoglobin molecule . 2)the mutant haemoglobin molecule suffers from low oxygen tension causing the change in the shape of the RBC from biconcave disc to elongated sickle like structure . Thalassemia-1)this defect arises due to mutation or deletion which ultimately results in reduced rate of synthesis of one of the globin chain that make up the haemoglobin. THALSSEMIA is the quantitive problem of synthesising too few globin molecule while the SICKLE-CELL ANAEMIA is the qualitative problem of synthesising an incorrectly functioning globin.

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What is cystic duct

Posted by Sanskriti Verma 7 years, 2 months ago

CBSE > Class 12 > Biology

1 answers

Harshvardhan Sharma 7 years, 2 months ago

The cystic duct is an important player in the digestive process. The system needs bile to help break down food and the cystic duct transfers bile between the gallbladder and common and hepatic bile ducts.

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According to 2011 census 1. No. Of male individuals- 2. No. Of female individuals- 3. No. Of individuals having pre reproductive age- 4. No. Of individuals having reproductive age-- 5. No. Of individuals having reproductive age---- Please give me this data

Posted by Parul Maiya 7 years, 2 months ago

CBSE > Class 12 > Biology

0 answers

ANSWER

What is glomerular filteration

Posted by Samshad Alam 7 years, 2 months ago

CBSE > Class 12 > Biology

1 answers

Hy Shona 7 years, 2 months ago

Glomerular filtrs a large amount of blood except protein it is called glomerular filteration.I think it is in eleventh syllabus.alam

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Cotard syndrome

Posted by Sahil Patre 7 years, 2 months ago

CBSE > Class 12 > Biology

2 answers

Hy Shona 7 years, 2 months ago

Thanks kaushik for this information

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Harshvardhan Sharma 7 years, 2 months ago

Cotard delusion is a rare mental illness in which the affected person holds the delusional belief that they are already dead, do not exist, are putrefying, or have lost their blood or internal organs.

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SHORT TYPE

Posted by Jyoti Yadav 7 years, 2 months ago

CBSE > Class 12 > Biology