CBSE > Class 12 > Biology | CBSE Board | Homework Help

Egg aparatus present inside embryo sac and embryo sac present inside ovule E appar . Is small in size Embryo sac is large as compared to egg aparatus Egg aparatus present single inside embryo sac, embryo sac may be 1 or more inside ovule Egg aparatus ploidy (n) Embryo sac is 7 celled ,8 nucleated structure Embryo sac get nurishmment from nucellus Egg aparatus get nurishmment from central cell of emb. sac

0Thank You

ANSWER

Pollen pistil interaction

Posted by Muskan Muskan 2 years, 6 months ago

CBSE > Class 12 > Biology

0 answers

ANSWER

What is important thing from human reproduction

Posted by Sehaj Karwal 2 years, 6 months ago

CBSE > Class 12 > Biology

2 answers

Anshika Bajpai 2 years, 6 months ago

Provided all organs are present, normally constructed, and functioning properly, the essential features of human reproduction are (1) liberation of an ovum, or egg, at a specific time in the reproductive cycle, (2) internal fertilization of the ovum by spermatozoa, or sperm cells, (3) transport of the fertilized ovum ...

0Thank You

Adarsh Maurya 2 years, 6 months ago

Fertilization is a crucial stage of reproduction in human beings.

0Thank You

ANSWER

What is latest syllabus of 2023-24 bio

Posted by Gangana Pandey 2 years, 6 months ago

CBSE > Class 12 > Biology

1 answers

Anshul Pratap Singh 2 years, 4 months ago

Only 13 ch is in our syllabus

1Thank You

ANSWER

To determine the percentage of pollen grain germination.

Posted by Ashifa Sayyed 2 years, 6 months ago

CBSE > Class 12 > Biology

2 answers

Preeti Dabral 2 years, 6 months ago

Formula for calculation of pollen grain germination.

Pollen fertility test (%) = number of stained pollen / Total number of pollen X 100

Pollen sterility test (%) = number of unstained pollen / Total number of pollen X 100

1Thank You

Ashifa Sayyed 2 years, 6 months ago

Thnk uh..

0Thank You

ANSWER

If there is anyone who is preparing for neet Which book is good for chemistry for practice sufficient questions?

Posted by Iva Jain 2 years, 6 months ago

CBSE > Class 12 > Biology

3 answers

Punit Yaduvanshi 2 years, 2 months ago

Pradeep's

0Thank You

Utkarsh Rathi 2 years, 5 months ago

Ncert at fingertips include every thing, more than 200 mcq in each chapter including ncert exempler , thinking skills, and pyq even A and R also.It is more than sufficient ,if you have modules of any coaching rather it is allen, akash,pw,motion .

1Thank You

Account Deleted 2 years, 6 months ago

Solve Ncert exempler , ncert at fingertips and pyq is must ..

2Thank You

ANSWER

Who is preparing for neet ??

Posted by Iva Jain 2 years, 6 months ago

CBSE > Class 12 > Biology

1 answers

Khushi Gupta 2 years, 3 months ago

Using a combination of self - study , regular practice , through revision, and solving mock tests.

0Thank You

ANSWER

What do you mean by vegetative propagation

Posted by Sumant Mishra 2 years, 6 months ago

CBSE > Class 12 > Biology

3 answers

Preeti Dabral 2 years, 6 months ago

The growth of new plants from vegetative parts of the plant like roots, stem, and leaves other than the seeds is called vegetative propagation. Various artificial methods of vegetative propagation are:

Cutting: Small piece of plant parts like roots, stem or leaves is cut and used for propagation. Examples: Rose, sugarcane etc.
Layering: It is the process where roots are induced when a stem comes in contact with the ground. Examples: Grapevine, mango etc.
Grafting: It is a process of joining a part of a living plant like a stem or bud to another plant and they grow as one plant. Examples: Lime, lemon etc.
Propagation by plant tissue culture: In this method, plant cells are cultured in an artificial culture media, where a cell divides into an undifferentiated mass of cells called callus which is transferred to different nutrient mediums to grow into plantlets.

In natural methods of vegetative propagation underground roots [Root tubers of Dahlia] or underground stems [bulbs of onions, rhizomes of ginger] or adventitious buds on leaves [Bryophyllum] grow into new plants.

0Thank You

Utkarsh Rathi 2 years, 5 months ago

Vegetative propagation is an asexual method of plant reproduction that occurs in its leaves, roots and stem. This can occur through fragmentation and regeneration of specific vegetative parts of plants.

0Thank You

Ashifa Sayyed 2 years, 6 months ago

The process in which new plants are grown from the old parts of another plant like roots, shoots, and leaves, without involving any reproduction organ is termed vegetative propagation.

0Thank You

ANSWER

How many of you apply for neet ??? Plz let me know.. and share your thoughts 💬 plz and also recommend any form except for neet....

Posted by Kashu Verma 2 years, 6 months ago

CBSE > Class 12 > Biology

0 answers

ANSWER

Explain the pollination types of pollinating agents and types of pollination, types of pollination occurring in the chasmogamous and cleistogamous flowers?

Posted by Soniya Panwar 2 years, 6 months ago

CBSE > Class 12 > Biology

1 answers

Preeti Dabral 2 years, 6 months ago

Flowers that open at maturity to facilitate exposure of pollen and stigma for cross-pollination are referred to as chasmogamous flowers. They are large, colourful flowers with nectar/scent to attract pollinators. Cleistogamous flowers remain closed to avoid cross-pollination.

Here Pollinations are of three types, namely:

1. Autogamy It is a type of self-pollination where the transfer of pollen grains from the anther to the stigma takes place within the same flower.

2. Geitonogamy Geitonogamy is the type of self-pollinations where the transfer of pollen grains from the anther to the stigma takes place between different flowers in the same plant.

3. Xenogamy Xenogamy is the cross-pollination where the pollen grain transfer occurs across the flowers of two different plants. In other words, the transfer of pollen from the anther of one plant to the stigma of another plant.

0Thank You

ANSWER

why regulation of gene expression is called as negative regulation ?

Posted by R.Sasi Kumar 2 years, 6 months ago

CBSE > Class 12 > Biology

1 answers

Preeti Dabral 2 years, 6 months ago

It is the process of regulating gene expression by inhibiting the expression of that specific gene. The repressor (a substance that can inhibit the expression of a gene) gets attached to the operator and inhibits the further process of gene expression.

0Thank You

ANSWER

What are the steps of producing transgenic animals?

Posted by Srishti Nagar 2 years, 6 months ago

CBSE > Class 12 > Biology

1 answers

Preeti Dabral 2 years, 6 months ago

The three principal methods used for the creation of transgenic animals are DNA microinjection, embryonic stem cell-mediated gene transfer and retrovirus-mediated gene transfer.

1Thank You

ANSWER

Ecosystem follows which law of thermodynamics? Does it follow both

Posted by Dharsh _ 2 years, 6 months ago

CBSE > Class 12 > Biology

2 answers

Preeti Dabral 2 years, 6 months ago

The energy flow in the ecosystem follows the second law of thermodynamics.”

0Thank You

Anjan Karthi 2 years, 6 months ago

It actually follows both laws. The unidirectional flow of energy in an ecosystem is an indicator of the first law and the fact that energy must not stop anywhere in the ecosystem, but must keep on flowing through the ecosystem, so that the universal tendency to disorder can be reduced.

0Thank You

ANSWER

Difference between macronutrients and micronutrients?

Posted by Its Prashant 2 years, 6 months ago

CBSE > Class 12 > Biology

1 answers

Nihal Ahirwar 2 years, 6 months ago

Macro provides energy while micro is necessary to body for functioning properly.

4Thank You

ANSWER

Can you tell me the pathway of sperm during ejaculation

Posted by Shinu Shanm 2 years, 6 months ago

CBSE > Class 12 > Biology

3 answers

Akshit Dogra 2 years, 3 months ago

Seminiferous tibules Then tibuli recti then rete testis then Vasa effrentia (intratesticular genital duct system) epididymis then Vasa defrentia then ejaculatory duct and then urethra (extra testicular genital duct system )then out through the urethral meatus

0Thank You

Anjan Karthi 2 years, 6 months ago

Seminiferous tubule → Rete testis → Vasa efferentia → Epididymis → Vas deferans → ejaculatory duct → urethra → urethral meatus.

0Thank You

Vidhi Miglani 2 years, 6 months ago

When ejaculation occurs, sperm is forcefully expelled from the tail of the epididymis into the deferent duct. Sperm then travels through the deferent duct through up the spermatic cord into the pelvic cavity, over the ureter to the prostate behind the bladder. Here, the vas deferens joins with the seminal vesicle to form the ejaculatory duct, which passes through the prostate and empties into the urethra.

1Thank You

ANSWER

Bone name

Posted by Nitesh Sharma 2 years, 6 months ago

CBSE > Class 12 > Biology

0 answers

ANSWER

Which type homework give me

Posted by Chanchal Patidar 2 years, 6 months ago

CBSE > Class 12 > Biology

0 answers

ANSWER

Millets are good source of diet for

Posted by Rajesh Aharwal 2 years, 6 months ago

CBSE > Class 12 > Biology

1 answers

Preeti Dabral 2 years, 6 months ago

Millet is rich in dietary fiber, both soluble and insoluble. The insoluble fiber in millet is known as a “prebiotic,” which means it supports good bacteria in your digestive system. This type of fiber is also important for adding bulk to stools, which helps keep you regular and reduces your risk of colon cancer.

0Thank You

ANSWER

How do Pleiotropy incomplete dominance co-dominance and polygenic inheritance deviate from the observation made by Mendel ? Explain with the help of example for each.

Posted by Dharsh _ 2 years, 7 months ago

CBSE > Class 12 > Biology

1 answers

Utkarsh Rathi 2 years, 5 months ago

search-icon-header Search for questions & chapters search-icon-image Question Bookmark How do incomplete dominance, codominance, polygenic inheritance and pleiotropy, deviate from Mendel's observation?Give an example of each. Medium Solution verified Verified by Toppr Incomplete dominance:- Mendel’s results were groundbreaking partly because they contradicted the (then-popular) idea that parents' traits were permanently blended in their offspring. In some cases, however, the phenotype of a heterozygous organism can actually be a blend between the phenotypes of its homozygous parents. For example, in the snapdragon, Antirrhinum majus, a cross between a homozygous white-flowered plant (C^WC^WC WC W ) and a homozygous red-flowered plant (C^RC^RC R C R) will produce offspring with pink flowers (C^RC^WC R C W ). This type of relationship between alleles, with a heterozygote phenotype intermediate between the two homozygote phenotypes, is called incomplete dominance. Codominance:- Closely related to incomplete dominance is codominance, in which both alleles are simultaneously expressed in the heterozygote. We can see an example of codominance in the MN blood groups of humans (less famous than the ABO blood groups, but still important!). A person's MN blood type is determined by his or her alleles of a certain gene. An L^ML M allele specifies production of an M marker displayed on the surface of red blood cells, while an L^NL N allele specifies production of a slightly different N marker.

0Thank You

ANSWER

What is relaxin?

Posted by Jitesh Kumar Mahto 2 years, 7 months ago

CBSE > Class 12 > Biology