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Suggest me the best channel or app to study ecology class 12 ....i have gone through many but couldn't find appropriate channel....

Posted by Anisha Sharma 6 years, 2 months ago

CBSE > Class 12 > Biology

2 answers

Sinchana Malagond 6 years, 2 months ago

Ncert is enough

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Aastha Saxena 6 years, 2 months ago

According to me..just read the chapters of ecology one by one with full concentration and mark all the examples of organisms described there.hope you will not want any channel to learn ecology ..

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DNA structure

Posted by Aman Siraj Ansari Aman Siraj 6 years, 2 months ago

CBSE > Class 12 > Biology

1 answers

Yogita Ingle 6 years, 2 months ago

The DNA structure can be thought of like a twisted ladder. This structure is described as a double-helix, as illustrated in the figure above. It is a nucleic acid, and all nucleic acids are made up of nucleotides.The DNA molecule is composed of materials called nucleotides, and each nucleotide is composed of three different components such as sugar, phosphate groups, and nitrogen bases.

The basic building blocks of DNA are nucleotides, which are composed of a carbon-sugar group, a phosphate group, and a nitrogen base. The sugar and phosphate groups link the nucleotides together to form each strand of DNA. Adenine (A), Thymine (T), Guanine (G) and Cytosine (C) are four types of nitrogen bases.

These 4 Nitrogenous bases pair together in the following way: A with T, and C with G. These base pairs are essential for the DNA’s double helix structure, which resembles a twisted ladder.

The order of the nitrogenous bases determines the genetic code or the DNA’s instructions.

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Androgens are synthesis by what

Posted by Aradhya Singh 6 years, 2 months ago

CBSE > Class 12 > Biology

3 answers

Muskaan Vig 6 years, 2 months ago

Androgens are synthesized by leydig's cell also called interstitial cells present in testes.........These cells are stimulated by Luteinizing hormone(LH) also called Interstitial cells stimulating hormone(ICSH)...

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Ns H 6 years, 2 months ago

By the action of LH hormone

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Prashant Patel 6 years, 2 months ago

testosterone

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How is the krebs cycle

Posted by Nitin Shahane 6 years, 2 months ago

CBSE > Class 12 > Biology

1 answers

Aakash Yadav 6 years, 2 months ago

This topic is from class 11th

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What is zift

Posted by anug****@***** 6 years, 2 months ago

CBSE > Class 12 > Biology

1 answers

Muskaan Vig 6 years, 2 months ago

ZIFT-Zygote Intra Fallopian Transfer..Egg from mother/donor and sperm from father/donor are taken and fertilized in vitro(outside the body) and after fertilization the zygote or early embryo with 8 blastomeres are transferred into fallopian tube of mother..Thus technique is used when mother is not able to produce egg or egg is not fertilizing at ampulla isthmus junction but it's uterus has conditions that can grow a zygote...

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Meaning of mutations are directionless.....

Posted by Muskaan Vig 6 years, 2 months ago

CBSE > Class 12 > Biology

2 answers

Muskaan Vig 6 years, 2 months ago

Thank you Yogita Ingle....but how are mutations ''directionless''??

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Yogita Ingle 6 years, 2 months ago

Mutation is the change that occurs in our DNA sequence due to environmental factors such as UV light, or due to the mistakes caused when the DNA is copied.

Our DNA can undergo changes in its base sequences A, C, G and T. This results in the changes in proteins that are synthesised by the DNA. Usually, the cells can recognize any damage that can be caused by mutation and repair it before it becomes permanent.

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What do you understand by chromosomal aberration ?explain the following: Duplication Deletion Inversion

Posted by Divya Rani 6 years, 2 months ago

CBSE > Class 12 > Biology

1 answers

Meghna Thapar 6 years, 1 month ago

The change in chromosome is due to alteration in genetic material through loss, gain or rearrangement of a particular segment. Such changes are called chromosomal aberrations. The modification brings about chromosomal mutations. i. Deletion - It is a loss of segment of chromosome. After break the part without centromere is lost. ii. Duplication - A segment of chromosome is repeated twice, i.e., duplicated. iii. Inversion - In this a chromosome segment is dropped out as a result of two breaks but it is reformed between two breaks after rotating through 1800o.

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What are biomes

Posted by Vishal Yadav 6 years, 2 months ago

CBSE > Class 12 > Biology

1 answers

Muskaan Vig 6 years, 2 months ago

Biosphere is divided into major regions called biomes........A Biome is community of flora and fauna occuping major habitat.Plants and animals of a particular biome have traits that help them to survive and thus organisms of a particular biome depend on each other....Eg.forests,deserts etc

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Biology notes

Posted by Prince Thakur 6 years, 2 months ago

CBSE > Class 12 > Biology

0 answers

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Explain the role of following in biotechnology (a) restriction enzymes (b) Gel-electrophoresis (

Posted by Khushi Soni 6 years, 2 months ago

CBSE > Class 12 > Biology

1 answers

Yogita Ingle 6 years, 2 months ago

(a) Restriction Endonucleases These are the bacterial enzymes that cut dsDNA into fragments after recognising and binding to the specific nucleotide sequences, known as recognition site. These enzymes are used to form recombinant molecules of DNA, composed of DNA from different sources.
(b) Gel-Electrophoresis is the technique which allows the visualisation of separated fragments of DNA on an agarose gel matrix.
Since, the DNA fragments are negatively charged molecules, they separate and move towards the anode (+ ve) under the influence of an electric field. DNA fragments are separated on the basis of their size through the sieving effect provided by the gel.

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All papaya plants bear flowers but fruits are seen only in some explain

Posted by Apurv Mangalam 6 years, 2 months ago

CBSE > Class 12 > Biology

2 answers

Muskaan Vig 6 years, 2 months ago

Because in those flowers pollination has not occured.....

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Muskaan Vig 6 years, 2 months ago

Papaya plants can be dioecious (male and female parts are present on different plants),monoecious (male and female part Are present on same plant but on different flowers) or can exihibit male and female parts on same flower ................................. for a fruit to arise pollination of flower is must.....so in dioecious condition sometimes pollination of either male or female part does not take place due to which only flower grows but doesn't bear any fruit......

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Where does fertilization in human take place

Posted by Shamim Ahmad 6 years, 2 months ago

CBSE > Class 12 > Biology

2 answers

Aman Dhaliwal 6 years, 2 months ago

at ampulla and isthmus junction in fallopian tube

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Mitali Jain 6 years, 2 months ago

In uterus

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Discrieb mendal law

Posted by Aanchla Aanchal 6 years, 2 months ago

CBSE > Class 12 > Biology

0 answers

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What are two reasons for recombination???

Posted by Shradha Ks 6 years, 2 months ago

CBSE > Class 12 > Biology

1 answers

Muskaan Vig 6 years, 2 months ago

Crossing over of chromosome segment during meiosis I i.e. exchange of dna segment on chromosome. Reasons for crossing over- leads to genetic variability..... Help to repair broken dna....

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Define convergent evolution and divergent evolution.

Posted by Dainashrre Mangsatabam 6 years, 2 months ago

CBSE > Class 12 > Biology

1 answers

Yogita Ingle 6 years, 2 months ago

CONVERGENT EVOLUTION	DIVERGENT EVOLUTION
When one or more different species evolve similarities in their characteristics and functions because of adaptations in an environment, it is called convergent evolution.	When an ancestral species diverges into multiple different species, ultimately giving rise to new species, it is called divergent evolution.
They evolve from different species but develops similar characteristics.	They evolve from the same species and gradually give rise to new species.
It is due to a change in environmental conditions, or due to the place where they are living.	It is due to migration or may be due to environmental changes.
Organisms evolve analogous structures.	Organisms evolve homologous structures.
Examples: Wings of insects, birds, bats.	Examples: Darwin finches.

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How habitat of organism effects organism reproduction?

Posted by Muskaan Vig 6 years, 2 months ago

CBSE > Class 12 > Biology

2 answers

Muskaan Vig 6 years, 2 months ago

Can you please give me any example?

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Shreyansh Gupta 6 years, 2 months ago

Organism lives by various means and they have different way of living in the environment and they have different matting among each other s o reproduction also varies

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Which are the major practicals in biology?

Posted by Arsh Pandher 6 years, 2 months ago

CBSE > Class 12 > Biology

3 answers

Ďãřşháñăã Yadav ? ? ? 6 years, 2 months ago

saliva test, DNA extraction

1Thank You

Shreyansh Gupta 6 years, 2 months ago

Only onion cell

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Muskaan Vig 6 years, 2 months ago

Pradeep sharma biology practicals how to get full marks You tube .... important and necessary practicals with marking scheme will be given there...

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Structure of flowers

Posted by Ravi Kishan 6 years, 2 months ago

CBSE > Class 12 > Biology

0 answers

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Explain the mechanism of *** determination in insects like drosophila and grasshopper

Posted by Harshita Nema 6 years, 2 months ago

CBSE > Class 12 > Biology

1 answers

Shiristi Gujjar 6 years, 2 months ago

In drosophila it is same as in humans... As male have XY chromosomes ND female have XX chromosomes........ ND in grasshopper male have XO chromosomes ND female have XX chromosomes

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What is the side effect of using cannabis

Posted by Victor Tensubam 6 years, 2 months ago

CBSE > Class 12 > Biology

2 answers

Muskaan Vig 6 years, 2 months ago

#1.Make person prone to depression. #2.weakens immunity of person. #3.stroke,heart disease,lung disease depending how the person consume it. #4. Affects cardiovascular system.

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Shiristi Gujjar 6 years, 2 months ago

It affects our cardiovascular system

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Why are night blooming flowers generally white ?

Posted by Shalini Singh 6 years, 2 months ago

CBSE > Class 12 > Biology

2 answers

Muskaan Vig 6 years, 2 months ago

Night blooming flowers are white because they attract moths and 'nocturnal insects' for pollination.And at night white colour is most visible one as it also reflects moonlight..

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Souromi Chatterjee 6 years, 2 months ago

To attract insects..

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How does the bee know which flower has nactar ?

Posted by Shalini Singh 6 years, 2 months ago

CBSE > Class 12 > Biology

2 answers

Muskaan Vig 6 years, 2 months ago

Bees can sense electrical charge of flower having nectar...If flower's nectar has already harvested by any other bee it's positive electrical charge increases and bee come to know that this flower has no nectar...Flower having nectar will have a different electrical field that bees sense .

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Souromi Chatterjee 6 years, 2 months ago

Its the work of the worker bee.. after they find the nectar they usually do the bee dance making an symbol of 8 that signals the other worker bee

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Power tissue

Posted by Pratibha Chauhan 6 years, 2 months ago

CBSE > Class 12 > Biology

0 answers

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What is microsporagium in simple words??

Posted by Dheeraj Jandu 6 years, 2 months ago

CBSE > Class 12 > Biology

2 answers

Muskaan Vig 6 years, 2 months ago

Future pollen sac in simple words...made of epidermis ->endothecium->middle layers->tapetum and contains pollen mother cells.

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Shiristi Gujjar 6 years, 2 months ago

The place in flower where development of pollen grains takes place

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Ethical issue in short

Posted by Numa Khan Numa Khan 6 years, 2 months ago

CBSE > Class 12 > Biology

1 answers

Shiristi Gujjar 6 years, 2 months ago

Moral isse

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Paractical paper

Posted by Nilesh Vaishnav 6 years, 2 months ago

CBSE > Class 12 > Biology

0 answers

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Ncert table 5.3 Comparison between the behaviour of chromosomes and genes... Can you tell which of these columns A or B represent the chromosome and which represents the gene? How did you decide?

Posted by Raman Deep Singh 6 years, 2 months ago

CBSE > Class 12 > Biology

2 answers

Bhavani Veer 4 years, 9 months ago

A col is gene and B col is chromosomes

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Muskaan Vig 6 years, 2 months ago

Column A is of gene and column B is of chromosome. #Gene-Pair of alleles of a particular gene will segregate independent from any other pair of allels of another gene present on same chromosome but are different locus(position)i.e. independent pairs segregate independently of each other. #Chromosome-one pair will segregate(><) independent of another pair(×).

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Offsprings produced by asexual reproduction is ref6as clones. Why?

Posted by Joyring Thoitak 6 years, 2 months ago

CBSE > Class 12 > Biology

2 answers

Aastha Saxena 6 years, 2 months ago

Because they are morphologically and genetically similar individuals

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Itisha Bathla 6 years, 2 months ago

Because the offspring produced are genetically or morphologically Similar to their parents that's why they are referred as clones

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Difference between standing crop and standing states

Posted by Revati Mali 6 years, 2 months ago

CBSE > Class 12 > Biology

1 answers

Venkat Ramanan 6 years, 2 months ago

Each trophic level has a certain mass of living material at a particular time called as standing crop. Whereas, the amount of nutrients such as carbon, nitrogen etc...present in soil at that time called standing state.

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What is rhizomes

Posted by Ateeq Ahmed 6 years, 2 months ago

CBSE > Class 12 > Biology