The answer is "c. Some alleles are dominant and other are recessive"
The xylem is the structure of the plant that is
responsible for transporting water from the ground up to the different parts of
the plant. It is composed water, inorganic ions, and a number of organic chemicals.
<span>
Xylem tissue is found throughout the plant
because not only does it transport water, but it also transports the nutrients
that the plant needs for different processes. Aside from being responsible for
the transportation of materials, the xylem is also used to replace water that
was lost during photosynthesis and transpiration. </span>
Answer:The lengthy small intestine receives secretions from the ______pancrease______ and ______liver______, completes digestion of the nutrients in _________chyme_______, absorbs the products of digestion, and transports the remaining residues to the ________large________ intestine.
Explanation: digestion of food is necessary for absorption of nutrients. In this process food is broken down into forms that can be absorbed by the body . food is broken down by the teeth and the enzymes in saliva,when it is in the mouth. From there it moves to the stomach through the oesophagus. In the stomach, the content is further mixed with enzymes and the churning breaks down food further.From the stomach food moves to the small intestine. In the small intestine, digestive enzymes from the pancreas and liver acts on food. The small intestine is where digested food is absorbed.it has a large surface area and finger-like projection called villi to carry out the function of absorbing nutrients.
From there, undigested food us passed to the large intestine from where it is passed out through the anus
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.
Cells become haploid in cytokinesis of meiosis one because the chromosomes have divided.
