Heating is still done largely by burning fuels, like it has been in the past, although people now have central heating to circulate the warm air throughout the house. Some people use electric heaters and people used to use cool water to cool their houses. Now people use electric air conditioners.
Answer:
Explanation:
<em>Tim and Stephanie are devastated when they find out their newborn son has hemophilia- sex-linked recessive disease. Tim is shocked because he doesn’t have hemophilia, and figured if his son has it he would have gotten it from him. Is Tim correct in his thinking? Explain. Also explain what their genotypes must be in order for neither parents to have the disease but their son does. Create a Punnett square, and indicate the mother's and father's genotype.</em>
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First of all, the thinking of Tim is wrong. Hemophilia is X-linked and a male (XY) child always inherits his X chromosome from his mother. Hence, <u>the newborn son of Tim must have inherited the allele for the disease from Stephanie.</u>
Now, neither Tim nor Stephanie showed any symptom of hemophilia. It could only mean that Tim is totally free of the hemophilic allele while Stephanie is a carrier for it. Because a man has just one X chromosome, he can either be totally free of the abnormality or affected by it, no in-between. A woman has two X chromosomes, hence, she can be totally free, a carrier, or affected for the disease. Assuming the allele for hemophilia to be h, Tim's genotype would, therefore, be 
while that of his wife would be 
.
The Punnet's square analysis of the cross between Tim and Stephanie is indicated in the attached image.
Ans.
Gene regulation or regulation of gene expression involves mechanisms, used by the cells to enhance or reduce the expression of specific genes to make proteins or RNA. Gene regulation occurs at transcriptional level and post-transcriptional level, which involves regulation at translational level or protein level.
Regulation at translational level or protein level is also important as regulation at transcriptional level. Translational regulation controls formation of proteins from mRNA molecules and includes non-coding mRNAs and repressor proteins. It is important for cell growth, differentiation and cellular response to stress and provides an immediate adjustment of gene expression by directly regulating the protein concentration.
Regulation at protein level involves regulation of active protein. It includes regulation by various small molecules, post-translational modifications (such as phosphorylation), and proteolysis. Regulation only at transcriptional level is not sufficient to provide proper gene regulation and leads to various drawbacks, such as Fragile X Syndrome (due to defect in a protein).
Thus, 'gene regulation is important both at transcriptional level and at post-transcriptional level (during translation or protein level).'
Choice 1 protons and neutrons, not electrons because they are in the outside circling it
