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Difference between Darwin and de varis explanation

Posted by Manisha Chandravanshi 5 years, 6 months ago

1 answers

Riya Rana 5 years, 6 months ago

According to hugo de vries evolution is due to mutation, it is a very fast process and directionless whereas, darwin said that evolution is due to variations it is a slow process and directional.

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Importaint diagram for board exam

Posted by Diksha Shrivastava 5 years, 6 months ago

CBSE > Class 12 > Biology

1 answers

Riya Rana 5 years, 6 months ago

Megasporogenesis

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Why can't planaria be the example of Fragmentation?

Posted by Subham Sahu 5 years, 6 months ago

CBSE > Class 12 > Biology

2 answers

Ayush Kumar 5 years, 6 months ago

Because planaria depend upon someone who cut it into many parts to reproduce. If it was an example of fragmentation then, it doesn't depend upon someone for reproduction, it can reproduce with itself..

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Mustafa John Pandit 5 years, 6 months ago

Nah, it can be an example of regeneration

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Pls tell me the scientific name of the organism on which Alexander Fleming worked on and discovered 1st antibiotic?

Posted by R M 5 years, 6 months ago

CBSE > Class 12 > Biology

9 answers

Naren Pal 5 years, 6 months ago

Penicillium notatum

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Muskaan Vig 5 years, 6 months ago

You are Welcome?.

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Ayush Kumar 5 years, 6 months ago

Streptococcus, meningococcus and diphtheria bacillus..

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R M 5 years, 6 months ago

Thanks you so much for explanation!??

1Thank You

Muskaan Vig 5 years, 6 months ago

Staphylococcus was the bacteria that was not able to grow because of fungi(mould) named "penicillium notatum" ..from this he found how to make a antibiotic using this fungi and to that antibiotic penicillin name was given....so.....bacteria- staphylococcus....fungi-penicillium notatum.....antibiotic-penicillin...

3Thank You

Subham Sahu 5 years, 6 months ago

Penicillin.

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R M 5 years, 6 months ago

Then what is staphylococcus??

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Ayush Kumar 5 years, 6 months ago

Penicillium notatum

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Nandlal Rajwade 5 years, 6 months ago

Penicillin

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ANSWER

Steps involved in PCR????

Posted by Sapna Rana 5 years, 6 months ago

CBSE > Class 12 > Biology

2 answers

Rahul Raj 5 years, 6 months ago

Denaturation Annealing Extension

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Ankita Krishwan 5 years, 6 months ago

Denaturation, annling, extension

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ANSWER

What is the rate of replication of E coli

Posted by Ankita Khatri 5 years, 6 months ago

CBSE > Class 12 > Biology

6 answers

Rahul Raj 5 years, 6 months ago

It completes replication in only 38 minutes

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Priyanshi Gupta 5 years, 6 months ago

18 mins- 2000 bp per sec

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Shankar .S 5 years, 6 months ago

2000 bp per second...??

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Amazing World 5 years, 6 months ago

2000bp sec 20min

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Riya Rana 5 years, 6 months ago

And 2000 bp per second

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Riya Rana 5 years, 6 months ago

20 min

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All the best to all for tomorrow exam..

Posted by Muskaan Vig 5 years, 6 months ago

CBSE > Class 12 > Biology

3 answers

Subham Sahu 5 years, 6 months ago

Same to u

1Thank You

Riya Rana 5 years, 6 months ago

Same 2 u ?

2Thank You

Shankar .S 5 years, 6 months ago

Same to you...

3Thank You

ANSWER

Why sickel cell anemia is called mandelian disorder ?

Posted by Varsha Tripathy 5 years, 6 months ago

CBSE > Class 12 > Biology

2 answers

Nishant Kapoor213 5 years, 6 months ago

Disorders explained by mendel laws called mendelian disorders.

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Gaurav Seth 5 years, 6 months ago

Sickle-cell anaemia is a blood related autosomal Mendelian disorder. It is an autosomal recessive genetic disorder. The disease is caused by a mutation in the beta-globin gene responsible for producing a subunit of haemoglobin. It is called Mendelian disorder because it is controlled by a single locus in an inheritance pattern and mutation in a single gene can cause a disease. Since it is a recessive disorder, two defected genes must be transferred from parents to offsprings in order to have the disease. When only one defective gene is transferred from the parent to offspriing, it results in the sickle cell trait. In this, the offspring is carrier of the diseas

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What is neocleotide?

Posted by Jannat Khan 5 years, 6 months ago

CBSE > Class 12 > Biology

1 answers

Gaurav Seth 5 years, 6 months ago

Nucleotides: Nucleotides contains all the three basic components of nucleic acids. Nucleotides are nucleoside monophosphates.

They are of two types depending upon the type of sugar – Ribonucleotides and Deoxyribonucleotides.

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Ask your doubts surely i will help you out.........trust me.......??

Posted by Kriti Sharma 5 years, 6 months ago

CBSE > Class 12 > Biology

6 answers

R M 5 years, 6 months ago

Scientific name of organism on which Alexander Flemming worked on to prepare penicillin??!! Plsss ans

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Shankar .S 5 years, 6 months ago

No more doubts... ?????All the best for ur bio xam...?????

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Nishant Sharma 5 years, 6 months ago

NO MORE DOUBTS...BEST OF LUCK KRITI????

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Shankar .S 5 years, 6 months ago

In a given population the frequency of alleles for brown fur is 0.6 and that of black fur is 0.4. What is the possible frequency of homozygous brown and heterozygous brown in the population assuming that the population is in the Hardy Weinberg equilibrium?

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Kriti Sharma 5 years, 6 months ago

Segment of DNA which codes for polypeptide is known as cistron.................. monocistron are mostly found in eukaryotes .............where as Poly cistronic are found in bacteria and prokaryotes..................???

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Lakshya ? 5 years, 6 months ago

Define a cistron. Giving example differentiate between monocistronic and polycistronic transcription unit

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What is polyspermy??

Posted by Shankar .S 5 years, 6 months ago

CBSE > Class 12 > Biology

5 answers

Shankar .S 5 years, 6 months ago

Name of ur school??

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Shankar .S 5 years, 6 months ago

67 out of 70??... In biology... Gud??

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Kriti Sharma 5 years, 6 months ago

Sure i got 67 ?

0Thank You

Shankar .S 5 years, 6 months ago

Thank you Kriti... Can u tell ur marks which you used to get in ur school??...

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Gaurav Seth 5 years, 6 months ago

Polyspermy refers to the penetration of multiple sperms (spermatozoa) into a single ovum at the time of fertilization. It occurs normally in certain species but only abnormally in species such as humans.

The remaining sperms die and disintegrate.

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What is EL Nino effect?

Posted by Divya Rathore 5 years, 6 months ago

CBSE > Class 12 > Biology

6 answers

Kriti Sharma 5 years, 6 months ago

The rise in temperature leading to odd climatic changes is called El Nino effect .....................the high temperature will result in melting of ice caps which will lead to rise in sea level and many coastal areas will be submerged ..........................the high levels of temperature lead to increased weed growth..................... eruption of diseases and pest .............thus crop productivity will decrease basically it is rising Global temperature ?

2Thank You

Shankar .S 5 years, 6 months ago

El nino effect means temporary change in temperature of earth

1Thank You

Shankar .S 5 years, 6 months ago

Wait I'll give a proper answer

1Thank You

Shankar .S 5 years, 6 months ago

But it's an example

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Shankar .S 5 years, 6 months ago

Global warming means increase in temperature of the earth's surface due to accumulation of green house gases. El nino effect is an example of global warming.

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Divya Rathore 5 years, 6 months ago

Give me answer

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U can ask questions to me, so that it would be easy for me to recall the points. And it would be helpful for you.

Posted by Shankar .S 5 years, 6 months ago

CBSE > Class 12 > Biology

0 answers

ANSWER

What is frameshift mutation

Posted by Dheeraj Jandu 5 years, 6 months ago

CBSE > Class 12 > Biology

2 answers

Yogita Ingle 5 years, 6 months ago

The mutation which is caused by the addition or deletion of nitrogen bases in the DNA or mRNA is called frameshift mutation. This mutation changes the sequence of amino acids, as a result, new proteins are formed.

1Thank You

Shankar .S 5 years, 6 months ago

Insertion or deletion of one or two bases change the reading frame from the point of insertion or deletion

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Ask questions???

Posted by Kriti Sharma 5 years, 6 months ago

CBSE > Class 12 > Biology

5 answers

Shankar .S 5 years, 6 months ago

U r so enthusiastic to answer any questions...

1Thank You

Shankar .S 5 years, 6 months ago

What is ur marks in ur school.

1Thank You

Shankar .S 5 years, 6 months ago

Hey!! Kriti Sharma... I like ur way of answering.

1Thank You

Kriti Sharma 5 years, 6 months ago

Which chapter

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Varalaxmi Sereginedi 5 years, 6 months ago

Main topics

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Why does a weed like calotropis grows in abandoned fields?

Posted by Mebin Baby 5 years, 6 months ago

CBSE > Class 12 > Biology

1 answers

Yogita Ingle 5 years, 6 months ago

Calotropis flourishes in abandoned fields because it has dry hairy seeds that help in its dissemination. The plant is adapted to xerophytic environment and has adaptations for that like thick hair on leaves and stems. Moreover, it is not grazed by animals as it produces poisonous substances.

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All allele are genes but all genes are not allele. Is it true if yes so explain this?????

Posted by Shefu ??????? 5 years, 6 months ago

CBSE > Class 12 > Biology

1 answers

Nishant Kapoor213 5 years, 6 months ago

This is ridiculous statement. Pair of genes called alleles. Now think urself does ur statement makes sense.

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Differentiation between microsporogenesis and megasporogenesis

Posted by Doyir Karlo 5 years, 6 months ago

CBSE > Class 12 > Biology

2 answers

Kriti Sharma 5 years, 6 months ago

Microsporogenesis......................... is the formation of microspores from Pollen mother cells through meiosis ..........................microspore which are formed are arranged as tetrad .................. so whenever the anther dehydrates these tetrads got separated out and four different pollen grains are formed ...........................and these pollen grains are generally spherical ...........................and comprises of two layers outer one is called exine ...................which is made up of sporopollenin......................... which is one of the most resistant chemical in the world .....................inner one intine is made up of cellulose and pectin.................................... megasporogenesis is very simple............... in the nucellus cells meiosis occur four cells are formed three of them degenerate........................ one is functional the one which is functional undergo Mitosis to form two nuclei........... then 4 nuclei then 8 celled stage ...............................out of the 8 nuclei 6 of them are organised by well developed cell wall.................. but the central one which are the two polar nuclei and enclosed by cell wall and there occurs a condition of 8 nuclei 7 cells....................... since there are three fusions happening 1 fusion with egg cell to form zygote ......................one fusion with first polar nuclei ....................second fusion with second polar nuclei................. it is termed as triple fusion ...............collectively the fertilization happening one with egg and one with whole polar nuclei to form primary endosper nucleus which is required for the development of the zygote.........?

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Yogita Ingle 5 years, 6 months ago

Microsporogenesis	Megasporogenesis
1.	It is the process of the formation of microspore tetrads from a microspore mother cell through meiosis.	It is the process of the formation of the four megaspores from a megaspore mother cell in the region of the nucellus through meiosis
2.	It occurs inside the pollen sac of the anther.	It occurs inside the ovule.

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ANSWER

how many marks diagram will come in exam??

Posted by Harman Sandhu 5 years, 6 months ago

CBSE > Class 12 > Biology

1 answers

Kriti Sharma 5 years, 6 months ago

Hi ..............................we cannot predict the marks for which diagram will come .....................because for. 5 mark question if it is not asked even then we have to draw the diagram ..........................for three mark also......................... so Biology is basically paper of diagrams and theory So we cannot escape diagrams in any question which is for 3 and 5 marks.................... if it is specially asked then it's obvious that we have to draw...................... but I advise you to revise the diagrams by heart because Biology paper is all about it .............???

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Difference between menstrual cycle and oestrous cycle

Posted by Amal S M 5 years, 6 months ago

CBSE > Class 12 > Biology

1 answers

Kriti Sharma 5 years, 6 months ago

Menstrual cycle occurs in primates like humans........... it is periodic and occurs every time in a month.............. and does not depend on season............... where as oestrous cycle it occurs depending on the season and time of mating of the organism that occurs in non primates like cows sheep dog.....?

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How many marks gain in biology exam tomorrow

Posted by J K 5 years, 6 months ago

CBSE > Class 12 > Biology

1 answers

Ayush Kumar 5 years, 6 months ago

As much you write..

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ANSWER

Phenotypy

Posted by Nitish Kumar 5 years, 6 months ago

CBSE > Class 12 > Biology

1 answers

Kriti Sharma 5 years, 6 months ago

Phenotype is basically what you see................... for example you see a flower with pink colour ....................then the pink colour that you are watching is its phenotypic character ...................but its genetic constitution is its genotypic character ...................for example you watch flower with five Petal then it is its phenotypic........??

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Ask your doubts i will answer them?

Posted by Kriti Sharma 5 years, 6 months ago

CBSE > Class 12 > Biology

18 answers

Mahesh M 5 years, 6 months ago

Krithi i love u??

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Nishant Sharma 5 years, 6 months ago

THANKS KRITI FOR THE ANSWER??

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Nishant Sharma 5 years, 6 months ago

NOPE! VIDYASHRAM AAYA HAI

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Rajat Barwar 5 years, 6 months ago

Nishant bhai tumhara centre subodh public school aaya hai kya??

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Kriti Sharma 5 years, 6 months ago

The discovery of lobe fns is considered very significant by evolutionary biologists ...........this is because they were the first amphibians on this earth more over there are the ancestors of modern day frogs ..salamanders.....?

2Thank You

Kriti Sharma 5 years, 6 months ago

?????might be ??

1Thank You

Nishant Sharma 5 years, 6 months ago

WHAT IS THE ANSWER OF LAST Q- DISCOVERY OF LOBE FINS IS CONSIDERED VERY SIGNIFICANT BY EVOLUTIONARY BIOLOGISTS?????PLZ HELP

1Thank You

Nishant Sharma 5 years, 6 months ago

BY KNOWING YOUR KNOWLEDGE I CAN SAY IT MUST BE A GOOD SCHOOL! THEY MUST BE PROUD TO HAVE SUCH SMART STUDENTS LIKE YOU!????

1Thank You

Kriti Sharma 5 years, 6 months ago

Yes typing mistake sorry ???

1Thank You

Kriti Sharma 5 years, 6 months ago

First question why are analogous structures a result of convergent evolution..................... state the significance of the study of fossils in evolution.................... question 3 name the scientist who disproved spontaneous generation theory.................next questions why are Wings of butterfly and Wings of bats called analogous .....................next question identify the following pairs as homeo logos or analogous sweet potato and potato......................... Eye of octopus and eye of mammals......................... Thorns of bougainvillea and tendrils of cucurbita ...................... and next question .....................what was proposed by oparin and haldane on origin of life ........................next explain adaptive radiation with the help of suitable .example ......................what is saltation according to de vries................. state the significance of coelocanth in evolution ................how is Darwin's concept of evolution different from devries............................................ how does fitness of a population help in evolution ..............................describe the three different ways by which natural selection can affect the frequency of heritable trait in a population ......................how does Hardy weinberg expression explain the genetic equilibrium list any two factors that affect it .............,.....discovery of lobe fins is considered very significant by evolutionary biologists .........explain................???

1Thank You

Nishant Sharma 5 years, 6 months ago

KRITI I THINK YOU HAVE WRITTEN UGA IN PLACE OF AUG IN ANSWER OF THE Q-MENTION THE ROLE OF CODONS AUG AND UGA..MAYBE THAT'S TYPING MISTAKE????LET ME KNOW IF IT IS WRONG OR NOT??

1Thank You

Kriti Sharma 5 years, 6 months ago

I am from DAV PUBLIC school BILASPUR HIMACHAL PRADESH??

2Thank You

Nishant Sharma 5 years, 6 months ago

CAN YOU PLEASE TELL SOME IMP. Q FROM EVOLUTION?THAT WOULD BE OF UTMOST HELP TO ME KRITI????

0Thank You

Nishant Sharma 5 years, 6 months ago

I'M FROM MAHESHWARI PUBLIC SCHOOL,JAWAHAR NAGAR,JAIPUR?? AND YOUR SCHOOL KRITI?????

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Nishant Sharma 5 years, 6 months ago

THANKS A LOT..HELPED ME VERY MUCH.THANKS FOR THE QUESTIONS AND ANSWERS TOO????

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Kriti Sharma 5 years, 6 months ago

Nishant from which school are you.?

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Kriti Sharma 5 years, 6 months ago

One of the most important is.......................... Packaging of DNA in eukaryotes and prokaryotes........................ in prokaryotes it is held with some proteins that are positively charged in a region called nucleoid .........................whereas in eukaryotes there is a set of positively charged proteins called histones............... that helps in the formation of histone octamer and packing happens................... difference between euchromatin and heterochromatin is very important ........................euchromatin stains light and is loosely packed where as Hetero chromatin which is also called inactive chromatin is complete opposite.................. diagram of replication fork.......,......... different types of RNA. process of replication.......... transcription and translation are all over very important .................process of capping and tailing.................. in capping nucleotides is added to the five prime and of hn RNA and in tailing adenylate Residue is added to 3 Prime template......................... and then Hn RNA transforms into mrna. ...............process of splicing .................dual function of a u g it acts as initiator codon.....................and codes for methionine................ adaptor molecule structure................ Lac Operon................. salient features of Human Genome Project ...............methodology of DNA fingerprinting............ let me give some important questions.........................,.............................................................................................................. also which I think are important from my point of view I think you should also do them............... how is repetitive DNA separated from bulk genomic dna ...??????????............the answer is Satellite DNA separated from bulk genomic DNA by density gradient centrifugation technique................. question number two ......mention the role of codons a u g and u g a during Protein synthesis ????????????U ga acts as initiation codon UGA as termination codon easypeasy.......................next question mention the contribution of genetic maps in Human Genome Project??????????? genetic maps uses starting point in Sequencing of whole genome ...............next question state which chromosome has maximum number of genes and which one has least number of gene....?????????? chromosome1 has maximum number of gene and chromosome y has least number of genes............... why is charging of trna necessary during translation ??????????process I think you can find it. yourself ......................write the full form of vntr how is vntr different from probe???????????? ??????

2Thank You

Nishant Sharma 5 years, 6 months ago

IMP. TOPICS OF MOLECULAR BASIS OF INHERITANCE AND EVOLUTION..PLZ????

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Also weightage for bio chapterwise

Posted by Anamika Bharti 5 years, 6 months ago

CBSE > Class 12 > Biology

2 answers

Nandini Singh 5 years, 6 months ago

There is no chapterwise weightage according to board it's unitwise Unit 1- 14 M Unit 2- 18 M Unit 3- 14 M Unit 4- 10 M Unit 5- 14 M

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Anamika Bharti 5 years, 6 months ago

Pls quickly.. ? My exam tomorrow

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ANSWER

How many MCQ will asked in bio board exam?

Posted by Gargee K 5 years, 6 months ago

CBSE > Class 12 > Biology

1 answers

Nandini Singh 5 years, 6 months ago

5 MCQ type questions would be there in biology board exam 2020

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ANSWER

Why is t rna called as an adapter molecule ?

Posted by Harshal Patil 5 years, 6 months ago

CBSE > Class 12 > Biology

2 answers

Muskaan Vig 5 years, 6 months ago

Adapter means "bridge"......tRNA has one acceptor site for amino acid and anticodon loop to attach with mRNA..... It is called an adapter molecule because it acts as a bridge between amino acids and mRNA....and formation polypeptide chain take place...via this

1Thank You

Gaurav Seth 5 years, 6 months ago

tRNA is called as an adapter molecule this is because of the fact that the tRNA attaches itself to the elongation factors of the ribosome that is mRNA complex.
The mRNA complex facilitates the attachment of correct amino acid to the growing polypeptide chain by the particular anticodon to the mRNA codon.

1Thank You

ANSWER

In comolete domience and co dominence

Posted by Neeraj Rautela 5 years, 6 months ago

CBSE > Class 12 > Biology

2 answers

Kriti Sharma 5 years, 6 months ago

Dominance.....................,... dominance just means something is dominant over the other right ........................incomplete dominance means no one is dominant ...................... in flowers called Snapdragon in which one of the parent is purely red and one of the parent is purely white.................................... but the F1 generation comes to be only pink which neither of the parents was........,................. this is pink colour is dominant in F1 generation..........,.,........ but none of the parent posseses i it means it is incomplete dominance.................................... and codominance human blood grouping system ..............,......in which both the alleles are able to express.......... if a parent have blood group A and second parent have blood group B .......................and if you are getting blood group O it doesn't mean that chance of getting A is Nil .....................,....it is present and can be expressed in future generation that is not eliminated but is expressed CO dominantly with the blood group O........???

2Thank You

Sapna Rana 5 years, 6 months ago

Incomplete dominance is the process in which the phenotypic ratio of F2 generation deviates from Mendel's monohybrid ratio........ Codominance is the phenomenon in which two alleles are able to express themselves indepently when present together.....

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Diffrent between insulin and pro insulin

Posted by Neeraj Rautela 5 years, 6 months ago

CBSE > Class 12 > Biology

1 answers

Kriti Sharma 5 years, 6 months ago

Insulin which consists of a b c peptide chains is called Pro insulin .......,.....................why prohormone because it is not a mature one as it is containing c-peptide ok...................... this c-peptide needs to be removed to convert it into mature insulin.................,..this. is the main difference between Pro insulin.... insulin is that of that extra stretch called c-peptide which is present in proinsulin but is absent in mature insulin this was one of the challenge for Eli Lilly and American company to make insulin in its mature form......????

2Thank You

ANSWER

Can i complete 16 chapters of bio in 1 day?

Posted by Tamir Khan 5 years, 6 months ago

CBSE > Class 12 > Biology

4 answers

Tamir Khan 5 years, 6 months ago

Times over now. Nothing can be done. Its upto god now.

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Ayush Kumar 5 years, 6 months ago

Fail

0Thank You

Kriti Sharma 5 years, 6 months ago

Yes........... you can complete 16 chapters in one day....................... but the condition is that ........................you should have studied them previously by heart............................ you must be well equipped with concepts of all the chapters ..........,......and gives only revision in one day otherwise it is difficult but not impossible......... if you haven't studied seriously................... then I advise you to just go for previous year questions................ and some important topics which are repeated ..............because if you now start to study the chapters you will get disappointed....... and feel overwhelmed............. you can ask your doubts here I will surely answer.........??

2Thank You

Sohrab Alam 5 years, 6 months ago

Agar kabhi nhi padha toh life mein kabhi nahi hoga

1Thank You

ANSWER

Marks distribution from each chapter

Posted by Bishal Bora 5 years, 6 months ago

CBSE > Class 12 > Biology