Speciation, when populations evolve to become distinct species
Answer:
a prezygotic barrier
Explanation:
Both wild tigers and lions are said to be reproductively isolated.
Reproductive isolation is defined as the existence of barrier between organisms of different species such that they cannot reproduce.
The mechanisms of reproductive isolation varies. While some act to prevent the formation of zygotes (in case of mating) between organisms of different species, some ensures that the resulting zygotes are invalid.
Reproductive isolation mechanisms that act to prevent fertilization and formation of zygotes are referred to as prezygotic mechanisms while those that ensure that invalid zygotes result (in case of successful fertilization) are referred to post zygotic mechanisms.
<em>The natural differences in the ranges of wild tigers and lions ensure that both animals do not mate with each other, let alone results in zygote. This is a form of pre-zygotic reproductive isolation mechanism.</em>
Answer:
Explanation:
hope it is helpful to you
Answer:
Surface area of the cube = 6cm²
Volume of the cube = 1cm³
Explanation:
The surface area of a cube, which refers to the sum of all the areas of the faces of the cube can be calculated using the formula:
S.A = 6 × a²
That is; a² + a² + a² + a² + a² + a²
Where;
a = length of a side of a cube
a² = area of one side of a cube
Note that, a cube has 6 faces
According to this question, a cube has a length of 1cm on each side.
Hence, S.A = 6 × 1²
S.A = 6 × 1
S.A = 6cm²
Volume of the cube can be calculated using the formula: a³
Where a = 1
Volume = 1 × 1 × 1
Volume = 1cm³
Answer:
The correct answer will be option-formation of heterochromatin
Explanation:
Methylation of DNA is the epigenetic mechanism which controls the expression of a gene by adding a methyl group to the cytosine bases in eukaryotic DNA.
The methylation of DNA converts the cytosine residues to the 5-methylcytosine catalysed by DNA methyltransferase enzyme. This results in the silencing of the gene and transcription get switched off.
Studies have shown that DNA methylation is involved in the formation and maintenance of the heterochromatin structure which is the condensed form of the chromatin in which transcription is switched off.
Thus, the formation of heterochromatin is the correct answer.
