Answer:
Either due to mistakes when the DNA is copied or as the result of environmental factors such as UV light and cigarette smoke.
The statement that best compares gymnosperms and angiosperms is : A. Both reproduce sexually, but gymnosperms contain only xylem and angiosperms contain xylem and phloem.
Gymnosperms produce exposed seeds, not enclosed in fruit whilst Angiosperms have Fruits, flowers, and endosperms as defining characteristics.
Answer:
true.
Explanation:
all the somatic cells of an organism have same number of chromosomes while gametes are haploid and have half number of chromosomes. so gametes are different from somatic cells.
Answer:
This is through the process of methylation and phosphorylation of histones tails.
Explanation:
The addition of a methyl group to the amino acid of the histones of the nucleosomes that compacted DNA in the nucleus is called mehtylation, while the addtion of phodpahte is phosphorylation
Its effects on gene expression depends on the number of <u> methyl groups, and type of amino acid that methylated. During transcription. </u>
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The DNA double strands are compacted and therefore hidden from transcription factors and enzymes of transcription by the hitones tails of the neuclosomes, Methylation weaken the binding bonds between the tails and DNA structure ; thereby aiding the uncoiling of DNA from the tails.(nucleosomes).This chemical reaction aided DNA strands exposure to transcription factors and enzymes, for initiation of transcription. This explains the dyanmic activity of methylation
Futhermore phophorylation also favours unwrapping of DNA, by imitating modifying enzymes e.g H3Y41E and H3T45E and convert it to→→ H3Y41phopspahte to aid DNA unwrapping and accessibility to transcription factors and RNA polymerase Enzymes,
