The disease called branched-chain ketoaciduria is commonly known as maple syrup urine disease, as the urine of a person with the condition has a smell similar to that of maple syrup. because the disease is rare and most often appears in children whose parents are first cousins, one can conclude that the disease is inherited as an autosomal phenotype.

Recessive

Explanation:

A recessive disorder is expressed in a homozygous genotype only. Most of the recessive disorders are not expressed as the expression of the recessive allele is masked by a dominant allele in the heterozygous state. However, breeding between close relative (inbreeding) increases the homozygosity in the population and allows the expression of recessive alleles that were otherwise not expressed in the population.

According to the given information, the disease is rare and is mostly expressed in the progeny obtained by mating between closely related individuals (the first cousins). Therefore the disease is inherited in an autosomal recessive pattern.

step 1: initiation

initiation is the beginning of transcription. it occurs when the enzyme rna polymerase binds to a region of a gene called the promoter. this signals the dna to unwind so the enzyme can ‘‘read’’ the bases in one of the dna strands. the enzyme is now ready to make a strand of mrna with a complementary sequence of bases.

step 2: elongation

elongation is the addition of nucleotides to the mrna strand. rna polymerase reads the unwound dna strand and builds the mrna molecule, using complementary base pairs. there is a brief time during this process when the newly formed rna is bound to the unwound dna. during this process, an adenine (a) in the dna binds to an uracil (u) in the rna.

step 3: termination

termination is the ending of transcription, and occurs when rna polymerase crosses a stop (termination) sequence in the gene. the mrna strand is complete, and it detaches from dna.

before, trains worked using the steam engine. thus, it uses heat so it is crucial to apply heat balance. the steam engine absorbs energy during the stage of boiling water. so, this is the endothermic reaction. when the steam is used to work the piston, it has to release this energy through running the train. the excess energy is released as an exhaust to the chimney. this is the exothermic process because it releases energy to the surroundings.