Without enough thyroid hormone, metabolism slows, making weight gain more likely. Even a thyroid functioning at the lower end of the normal range might cause weight gain. Treating hypothyroidism with medication may reverse some of the weight gain. If you have any concerns, seek medical advice.
1 Allele: a different version of a gene. 2  Dominant: a trait that is visible and can cover up other traits when there is more than one present. 3  Genotype: the genetic makeup of an organism, or the versions of a gene that an organism has. 4  Heterozygous: having two different versions of a gene.
] of most cells. They consist of long strands of a substance called deoxyribonucleic acid, or DNA for short. A section of DNA that has the genetic code for making a particular protein is called a gene.The gene is the unit of inheritance, and each chromosome may have several thousand genes.hey consist of long strands of a substance called deoxyribonucleic acid, or DNA for short. A section of DNA that has the genetic code for making a particular protein is called a gene. The gene is the unit of inheritance, and each chromosome may have several thousand genes.