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

Restriction enzymes are like scissors; they cut up DNA at specific regions. These enzymes are found in bacteria (prokaryotes) but not in eukaryotic cells. Naturally occurring restriction endonucleases are categorized into four groups (Types I, II, III, and IV) based on their composition and enzyme cofactor requirements, the nature of their target sequence, and the position of their DNA cleavage site relative to the target sequence. No, eukaryotic cells do not have restriction endonucleases. This is because the DNA of eukaryotes is highly methylated by a modification enzyme, called methylase. Methylation protects the DNA from the activity of restriction enzymes. These enzymes are present in prokaryotic cells where they help prevent the invasion of DNA by a virus.

0Thank You

ANSWER

What is malt extaction

Posted by Gursharn Kaur 6 years, 5 months ago

CBSE > Class 12 > Biology

1 answers

Meghna Thapar 5 years, 8 months ago

Malt extract is sugar extracted from malted grain. It comes in two forms: liquid or dry malt extract (LME and DME, respectively). LME is a thick, sugary syrup, and DME is a dry powder. Manufacturers use sophisticated equipment to condense malt extract by carefully evaporating much of the water. Malt extract is frequently used in the brewing of beer. Its production begins by germinating barley grain in a process known as malting, immersing barley in water to encourage the grain to sprout, then drying the barley to halt the progress when the sprouting begins.

0Thank You

ANSWER

Why are flocs important in biological treatment of waste water

Posted by Laxmi Singh 6 years, 5 months ago

CBSE > Class 12 > Biology

2 answers

Sia ? 6 years, 5 months ago

Flocs are important in the biological treatment of wastewater as when the flocs grow, they consume a major part of the organic matter in the effluent. This significantly reduces the BOD of the effluent.

1Thank You

Jyotiprakash Mohanty 6 years, 5 months ago

Because they help to digest the organic matter present it in the water and help to decrease the level of BOD .BOD help to measure the organic matter present in the water

0Thank You

ANSWER

Kya bio mai bhi mcq aayega kyun ki sa-I mai nahi aaya tha

Posted by Nitish Mahto 6 years, 5 months ago

CBSE > Class 12 > Biology

2 answers

Mrutyunjay Khatua 6 years, 5 months ago

According to CBSE sample question paper 2019-20 ,the first five VSA (1 mark) questions will be MCQs.

0Thank You

Gursharn Kaur 6 years, 5 months ago

Nahi aayega. 1 mark ke question aayege

1Thank You

ANSWER

What is the difference between prokaryotic DNA and eukaryotic DNA

Posted by Bilal Qureshi 6 years, 5 months ago

CBSE > Class 12 > Biology

1 answers

Raman Brar 6 years, 5 months ago

Prokaryotic dna is not arranged in nucleus while eukaryotic dna is packed in nucleus.

3Thank You

ANSWER

Difference between vaccination and immunization

Posted by Saroj Kumar Mohanta Saroj Kumar Mohanta 6 years, 5 months ago

CBSE > Class 12 > Biology

1 answers

Yogita Ingle 6 years, 5 months ago

Vaccination	Immunization
The process involves Introducing a weakened / deactivated disease causing microbes into a person	The process starts after the person is exposed to the vaccine and the body starts building resistance to that disease
It is usually injected or administered orally	It is not administered in any way, the body develops the resistance from vaccines
Imovax Rabies is the trade name for rabies vaccine	The body builds up immunity through this vaccine for the disease rabies
Vaccination does not guarantee complete resistance to a disease	Complete immunity occurs when the person fully recovers from the disease
Usually, if mutation happens to microbe, it might render the vaccine ineffective (this is the reason why common cold has no vaccine)	Similarly, variations of a disease impact the body’s ability to generate an immune response

1Thank You

ANSWER

How many base pairs and tRNA are required for the synthesis of 14 amino acids!?

Posted by Sidhardth S Kumar 6 years, 5 months ago

CBSE > Class 12 > Biology

1 answers

Meghna Thapar 5 years, 6 months ago

Each tRNA has a distinct anticodon triplet sequence that can form 3 complementary base pairs to one or more codons for an amino acid. Some anticodons pair with more than one codon due to wobble base pairing. tRNAs bring their amino acids to the mRNA in a specific order. This order is determined by the attraction between a codon, a sequence of three nucleotides on the mRNA, and a complementary nucleotide triplet on the tRNA, called an anticodon. This anticodon also specifies the particular amino acid that the tRNA carries.

0Thank You

ANSWER

Difference between exon and intron

Posted by Patherlay Surbhi 6 years, 5 months ago

CBSE > Class 12 > Biology

1 answers

Yogita Ingle 6 years, 5 months ago

Introns	Exons
Found in Eukaryotes only	Found in both prokaryotes and eukaryotes
Non-coding areas of the DNA	Coding areas of the DNA
Introns are the transcribed part of the nucleotide sequence in an mRNA and are known to carry the non-coding part for the proteins	Exons are the transcribed part of the nucleotide sequence in mRNA that is responsible for the protein synthesis.
The sequence of the introns changes frequently over time. In other words, they are less conserved	Exons are highly conserved
DNA bases found in between exons	DNA bases that are translated to mRNA
Even after the mRNA splicing, introns continue to remain in the nucleus	When mature mRNA is produced, exons move to the cytoplasm from the nucleus

1Thank You

ANSWER

what is *** determination in honey bee

Posted by Shalini Roy 6 years, 5 months ago

CBSE > Class 12 > Biology

1 answers

Sinchana Malagond 6 years, 5 months ago

Haplodiplontic type also called arrhenotoky.

1Thank You

ANSWER

Spermatogenes definition with diagram

Posted by Sahil N Shekhaji 6 years, 5 months ago

CBSE > Class 12 > Biology

1 answers

Shalini Roy 6 years, 5 months ago

, that is spermatogenesis not spermtogenes

0Thank You

ANSWER

Amnestics is an association between two spicier where

Posted by Vaibhav Dixit 6 years, 5 months ago

CBSE > Class 12 > Biology

0 answers

ANSWER

What is meant by malting

Posted by Sakshi Kaur ?? 6 years, 5 months ago

CBSE > Class 12 > Biology

1 answers

Vaibhav Dixit 6 years, 5 months ago

Malt is germinated cereal grain that has been dried in a process known as "malting". The grain is made to germinate by soaking in water and is then halted from germinating further by drying with hot air.

1Thank You

ANSWER

Stored fat in blubber of whales and hump of camel is white or brown.?

Posted by Anubhuti Shrivastava 6 years, 5 months ago

CBSE > Class 12 > Biology

1 answers

Sia ? 6 years, 5 months ago

The blubber of the whale and hump of the camel is made up of Adipose tissue. Adipose tissue is a connective tissue found under the skin and stores fats of the body.

0Thank You

ANSWER

what is hermaphrodites

Posted by Babulal Balach 6 years, 5 months ago

CBSE > Class 12 > Biology