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Plants encourage self fertilization if their genotype is well suited for the environment or when there is absence of any pollinating agents.

Parasitic beings like Tapeworm self fertilise as they stay in host body for the whole life and can't look for a mate

Snail , Fishes & Echinoderms self-fertilize in order to increase their number in short time and spending less energy & resources

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Mandeep Sharma 6 years, 7 months ago

In cleistogamous and self compatible flowers

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Why there is stopage of mensturation during pregnency

Posted by Tripti Kukreti 6 years, 7 months ago

CBSE > Class 12 > Biology

3 answers

▪▪Amrit▪▪ ❤ 6 years, 7 months ago

DUE to the hormones as HCGhormone is s3 reted during pregnency and estrogen and progestogen also imbalances

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Mandeep Sharma 6 years, 7 months ago

Because the primary oocyte in the ovary degenerates with age and till the age 50 all primary oocyte gets degenerate

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Team Film Production 6 years, 7 months ago

Due to foetus. In womb after embryogenesis the offspring capture whole space of womb as well as the ovary doesn't able to produce ova in pregnancy...

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In. Incomplete dominance F1 generation is differ from both of its parents

Posted by Abhishek Srivastava 6 years, 7 months ago

CBSE > Class 12 > Biology

1 answers

Shivam Jaiswal 6 years, 7 months ago

Yes it is true indeed Red *white= pink f1 generation Pink*pink (selfing f1 generation ) =1:2:1 ratio I.e 1 red 2 pink 1 white

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Importance of seed

Posted by Kakoli Sharma 6 years, 7 months ago

CBSE > Class 12 > Biology

3 answers

Gursharn Kaur 6 years, 7 months ago

Helps in the production of a new plant or crop act as food for us promotes continuity of species may help in the creation of variations which leads to evolution

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Shivam Jaiswal 6 years, 7 months ago

W/o seed only parthenogenesis will occour will you be comfortable to eat parthenocarpic food throughout life

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Kiara Khurrana 6 years, 7 months ago

seed humhari mata hai humko kuch nhi aata hai

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Is "Dna" fingerprinting "a nic topic fr investigatory project fr bio ??

Posted by Tanushree Shenoi 6 years, 7 months ago

CBSE > Class 12 > Biology

3 answers

Tanushree Shenoi 6 years, 7 months ago

Wts pcr???@shivam jaiswal

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Tanushree Shenoi 6 years, 7 months ago

Pcr??

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Shivam Jaiswal 6 years, 7 months ago

Yes i taked this topic previous year it is quite interesting and easy Listen add as case study as possible to make ur project good ur benefited for viva read project with ncert also include pcr in it in place of amplification

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Actually i wanna know ....in field of biochemistry what are job opportunities.....and in chennai is there any institute fr persuing it....orto knw more abt it???7plz ans

Posted by Tanushree Shenoi 6 years, 7 months ago

CBSE > Class 12 > Biology

3 answers

Tanushree Shenoi 6 years, 7 months ago

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Shivam Jaiswal 6 years, 7 months ago

Forensic sci is best i think so

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Kiara Khurrana 6 years, 7 months ago

r u in class 12

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How many mitotic division take place in "Bisporic embryo".

Posted by Siddharth Verma 6 years, 7 months ago

CBSE > Class 12 > Biology

1 answers

Meghna Thapar 5 years, 4 months ago

During development of the corn embryo sac, which displays the so-called polygonum type of development, three mitotic divisions give rise to two groups of four nuclei, one at the end closest to the embryo (the micropylar end) and one in the opposite (chalazal) end of the embryo sac. Based on the number of megaspores, embryo sacs can be divided into three types: monosporic, bisporic, and tetrasporic. In the monosporic, or Polygonum-type embryo sac, meiosis of the diploid megaspore mother cell in the nucellus produces four haploid megaspores.

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Reproductive organs is

Posted by Aanand Kumar 6 years, 7 months ago

CBSE > Class 12 > Biology

1 answers

Himanshu Raj 6 years, 7 months ago

In male- testis,rete testis, vasa efferentia,epididymis,vas deference,ejaculatory duct, urethra and external genitalia *****. in female - ovaries, oviducts,uterus,cervix,******,and external genitalia

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Give reason why some fruits are seedless or contain empty or non viable seeds.

Posted by Yash Rajpoot 6 years, 7 months ago

CBSE > Class 12 > Biology

3 answers

Shivam Jaiswal 6 years, 7 months ago

These are fruit which devlop without fertilization and phenomenon is parthenogenesis fruit is known as parthenocarpic

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Sinchana Malagond 6 years, 7 months ago

Due to parthenogenesis

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Sarthak Shukla 6 years, 7 months ago

Bcoz of other parts get degenerate

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Why do integuments of an ovule harden and the water content is highly reduced as the seed matures. Also Justify ur answer.

Posted by Yash Rajpoot 6 years, 7 months ago

CBSE > Class 12 > Biology

1 answers

Harsh Pahuja 6 years, 7 months ago

Integument of an ovule hardens to form seed coat(testa + tegmen)as a protective outer covering. While the water contents is highly reduced to activate the dormancy state of seed.

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Give reason why hybrid seeds are to be produced year after year. Also, justify ur answer.

Posted by Yash Rajpoot 6 years, 7 months ago

CBSE > Class 12 > Biology

2 answers

Gursharn Kaur 6 years, 7 months ago

They are reliable only for some time so their is need new hybrid seeds year after year

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Sinchana Malagond 6 years, 7 months ago

To increase the yeild and get better quality of seeds n its only possible only by doing apomixis since in sexual reproduction there is segregation of characters and leads to variable characters among individuals

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Why does self - pollination not lead to seed formation in self-incompatible species.

Posted by Yash Rajpoot 6 years, 7 months ago

CBSE > Class 12 > Biology

1 answers

Gursharn Kaur 6 years, 7 months ago

This may be because may the plant of flower maybe unisexual it means thatonly one of either male or female reproductive organ may present

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Why do some plants have both chasmogamous and cleistogamous flowers ? Also, Justify your answer.

Posted by Yash Rajpoot 6 years, 7 months ago

CBSE > Class 12 > Biology

1 answers

Meghna Thapar 5 years, 5 months ago

Flower which remains open and exposes the anther and stigma are called chasmogamous flowers. Cleistogamous flowers do not open at all. Because anthers and stigma are not exposed, cross pollination cannot take place in such cases. To promote cross-pollination, chasmogamous flowers often have strikingly colored petals and nectar guides/nectaries to attract and reward pollinators. The closed morphology of cleistogamous flowers hinders them from exposing their reproductive organs and forces self-pollination.

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How to study for compartment exam

Posted by Manish Kumar 6 years, 7 months ago

CBSE > Class 12 > Biology

1 answers

Shivam Jaiswal 6 years, 7 months ago

Ncert remember important points

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Blue print of 2020

Posted by Rajbir Singh 6 years, 7 months ago

CBSE > Class 12 > Biology

0 answers

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Describe the phenomenon which occur in zygote during embryogenesis

Posted by Ruchi Mavi 6 years, 7 months ago

CBSE > Class 12 > Biology

2 answers

Aysha Enami 6 years, 7 months ago

Zygote undergoes cell division and cell differentiation.

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Soban Soban 6 years, 7 months ago

Mitosis occur in zygote during Embryogenesis

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What is the advantage of apomicis ?

Posted by Sumit Singh 6 years, 7 months ago

CBSE > Class 12 > Biology

2 answers

Tanuj Kumar 6 years, 7 months ago

Hii

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Antriksh Bohara 6 years, 7 months ago

advantage of apomixis in plant breeding 1. without risk of seggregation , rapid multiplication of genetically uniform individuals can be achieved. 2. heterosis or hybrid vigour can permanently be fixed in crop plants, thus no problem for recurring seed production of F1 hybrid. 3. efficient exploitation of maternal effect , if present , is possible from generation to generation

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How many ques in NEET 19 asked from biology NCERT

Posted by Time Over 6 years, 7 months ago

CBSE > Class 12 > Biology

1 answers

Sudarshan Sharma 6 years, 7 months ago

Nearly 88 to 89

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Best book for biology for entrance

Posted by Ashu Baba 6 years, 7 months ago

CBSE > Class 12 > Biology

3 answers

Shivam Jaiswal 6 years, 7 months ago

Trueman is best book it is helpful in cbse state boards neet cet jipmer and aiims

1Thank You

Harsh Pahuja 6 years, 7 months ago

Trueman

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Tanushree Shenoi 6 years, 7 months ago

Pradeep or. Mtg

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What is haploid and diploid cells

Posted by Sarika Pandey 6 years, 7 months ago

CBSE > Class 12 > Biology

1 answers

Kanisha Dahiya 6 years, 7 months ago

Haploid are those cells which have half set of chromosomes while diploid are thise which have full set of chromosome s

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Hermaphrodite

Posted by Ankita Das 6 years, 7 months ago

CBSE > Class 12 > Biology

1 answers

Ruchi Mavi 6 years, 7 months ago

Which has both *** organ but mature at one

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at what stage does the meiosis occur in an organism exhibiting haploidic life cycle and mention the fate of the products thus produced.

Posted by Yashvee .Student 6 years, 7 months ago

CBSE > Class 12 > Biology

1 answers

Sinchana Malagond 6 years, 7 months ago

At zygotic level meiosis occurs in haplontic organisms so as to maintain their ploidy level kindly refer ncert class 11 text book life cycle exhibited by haploid organisms

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Monascus purpurea are statin or ethanol

Posted by Vinay Kumar 6 years, 7 months ago

CBSE > Class 12 > Biology

1 answers

Aishwarya S 6 years, 7 months ago

Monascus purpureus is used in synthesising Statin

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Vulva

Posted by Prajesh Prajapati 6 years, 7 months ago

CBSE > Class 12 > Biology

2 answers

Souromi Chatterjee 6 years, 7 months ago

Vulva is the external genitalia of human females.. it consist of mons pubis, ***** majora ,***** minora,********, hymen,urethral and vaginal openings.. it mainly protects the internal sexual organs of woman.. it also consist of two glands namely bartholin's gland and glands of skene that lubricates vaginal canal during sexual intercourse.

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Harshi Rajput 6 years, 7 months ago

The vulva is the external part of the female genitalia. It protects a woman's sexual organs, urinary opening, vestibule and ******

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Diff. Between primary and secondary follicles

Posted by Rakesh Kadiyan 6 years, 7 months ago

CBSE > Class 12 > Biology

1 answers

Unknown Villain 6 years, 7 months ago

The primary oocyte is surrounded by some granulosa cells called primary follicle and these primary follicle are surrounded by some extra granulosa cells called secondary foolicle

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Nature's biological library is burning even before we catalogued the titles of all the books stock there. Explain

Posted by Rhythm T 6 years, 7 months ago

CBSE > Class 12 > Biology