A triploid cell is the structure form during angoisperm fertilization. The cell are created in the process known as double fertilization into the endosperm which is mostly are polyploid. These are typicallly triploids that is they contain three sets of chromosomes but they varies widely from diploid (2n) to 15N.
Answer:
The animal cell will shrink due to loss of water to the external solution
Explanation:
An isotonic solution is that solution which has equal concentration with its external environment. Hence, no net movement of water occurs in an isotonic solution since there is no concentration gradient. Therefore, if an animal cell is placed in an isotonic solution at first, no net movement of water occurs because the intracellular and extracellular concentrations are at equilibrium.
However, if more solutes are added to the solution, it makes the solution HYPERTONIC to the cell i.e greater in concentration. This creates an osmotic gradient and causes water to move out of the animal cell into the solution in accordance to osmotic principles (movement of water from a low concentration of solute to high concentration of solute). This causes the animal cell to likely SHRINK.
Answer:
The fact that most eukaryotes reproduce sexually is evidence of its evolutionary success. In many animals, it is actually the only mode of reproduction. The genetic diversity of sexually-produced offspring is thought to give species a better chance of surviving in an unpredictable or changing environment.
Answer:
C) Through genomic imprinting, methylation regulates expression of the paternal copy of the gene in the brain.
Explanation:
The pattern of gene expression wherein either paternal or maternal gene is expressed in specific cells while the other one is prevented from expression is known as genomic imprinting.
In the given example, the maternal copy of the gene on chromosome 15 is expressed in brain cells while its paternal copy is not expressed in these cells. Hence, the pattern of expression of this gene is regulated through genome imprinting. One of the mechanism is methylation of cytidine residues of CpG islands of the DNA that are more frequently present within promoters of the genes.
When the cytidine residues of these sequences are methylated into 5-methylcytidine, the transcription factors do not bind to these promoters preventing the expression of these genes.
Hence, methylation of cytidine residue in CpG islands of the promoters of the gene present on chromosome 15 could have silenced its expression in brain cells.
