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3 years ago

Deﬁne mutation and mutagen.

1 answer:

4 0

Mutations. Definition. A Mutation occurs when a DNA gene is damaged or changed in such a way as to alter the genetic message carried by that gene. A Mutagen is an agent of substance that can bring about a permanent alteration to the physical composition of a DNA gene such that the genetic message is changed.

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Which of the following lists steps of mRNA production in eukaryotes in the correct order?A) 5' cap addition, addition of poly-A

Assoli18 [71]

Answer:

The correct answer is B) Transcription, 5' cap addition, addition of poly-A tail, exon splicing, passage through nuclear membrane.

Explanation:

The transcription process in eukaryotes takes place in the nucleus of the cell and after transcription post-transcriptional modification also takes place in the nucleus which is necessary to guide the mRNA out of the nucleus.

First, the process of transcription takes place in which DNA is transcribed to mRNA by an enzyme called RNA polymerase. After transcription post-transcriptional modifications takes place in the given order.

1. Capping: In capping process 7-methylguanosine is added by capping enzyme at 5' end of mRNA.

2. Polyadenylation: In polyadenylation, many poly-A residues are added at the 3' end of the mRNA called the poly-A tail.

3. Intron splicing: Introns are the non-coding sequence present in mRNA which are spliced out of mRNA and all exons are joined together.

After these post-transcriptional process, the mature mRNA is transported out of the nucleus through the nuclear membrane.

5 0

3 years ago

The concentration of sugar is higher inside a cell than outside the cell. The concentration of water inside the cell is lower th

Scorpion4ik [409]

A because osmosis will act to balance the concentrations of water inside and outside the cell. As this happens, sugar outside the cell will dissolve into the water and be moved across the cell membrane with it into the cell. This continues until the concentrations are equal.

3 0

3 years ago

Can somebody give me the answer for these...

labwork [276]

Answer:

1. Life cycle of a cell starts from

G1 phase - S phase (synthesise phase) - G2 phase - mitosis.

2. By mitosis bcoz it restore nucleo cytoplasmic ratio means ploidy of cell remain same.

3. Bcoz of transformation of normal cells into cancerous cells by Carcinogens present in tobacco.,drugs .etc

4 mitosis occurs in plants animals

Binary fission occurs in bacteria and other single celled organism.

Both give rise to two daughter cells.

5.sex cells (n) are produced by meiosis from gamete mother cells(2n).

6.in meiosis ploidy of cell become half

Means diploid cell form haploid cells

And 4 haploid daughters cells are formed.

In mitosis, ploidy of cell remain same

Means haploid form haploid and diploid form diploid.

1 cell form 2 daughter cells.

Hope this helps you.. Frnd ❤️

4 0

3 years ago

Independent variable:

Leokris [45]

IV: 4 types of nail polish

DV: brand of nail polish that lasts the longest

Control: nails

Constant: bottom coat and top coat

Experimental Group: Nail polish

Hypothesis: The types of nail polish would eventually chip away after a week .

7 0

3 years ago

The sensory division of the pns is also known as the efferent division. true or false

choli [55]

This would be true.

Thanks :)

5 0

4 years ago