A point mutation is a simple change in one base of the gene sequence. This is equivalent to changing one letter in a sentence, such as this example, where we change the ‘c’ in cat to an ‘h’:

Original: The fat cat ate the wee rat.

Point Mutation: The fat hat ate the wee rat.

Sickle cell anaemia is caused by a change in a single base pair of DNA. Sickle-cell anaemia is the name of a specific form of sickle-cell disease in which there is homozygosity for the mutation that causes HbS. Sickle-cell disease, or sickle-cell anaemia (ordrepanocytosis), is a life-long blood disorder characterized by red blood cells that assume an abnormal, rigid, sickle shape. Sickling decreases the cells flexibility and results in a risk of various complications.

Klinefelter’s syndrome is a genetic disorder affecting men in which an individual gains an extra X chromosome, so that the usual Karyotype of XY is replaced by one of XXY include female characteristics (such as breast enlargement).

The two chains are antiparallel, one aligned in 5’ → 3’direction the other in 3’ → 5’ direction.

Let GG ⇒ homozygous yellow seed plant.

Gg ⇒ heterozygous green

gg ⇒ homozygous green

According to the question :

It would make only two types of gametes, these are ABC & AbC.

A cross of F₁ hybrid with its recessive homozygous parent is called the test cross. It is done to determine the genotype of a given plant. If the given plant has homozygous dominant traits then on test cross it gives all dominant trait plants but if it is heterozygous dominant than it gives dominant and recessive phenotypes in 1 : 1 ratio.

In sickle cell anaemia RBCs become sickle shaped which are not supportive for the growth of malarial parasite Plasmodium so it provides immunity against malaria disease.

Sickle cell anaemia is a biochemical disorder in which shape of RBCs become sickle-shaped due to the defective haemoglobin. Haemoglobin becomes useless for oxygen transport.

Huntington Chorea is a disease in which atrophy of brain occurs resulting to respiratory irregulations, articulation of speech and irregular limbs movements take place. They both are genetic disease present in any person since birth hence congenital diseases.

Polygenic inheritance is the inheritance of traits which are dependent on the no. of genes such as the skin colour of human beings, eg. AABB is black AaBB in neither dark nor black. AaBb is again wheatish Aabb is light and aabb is white colour.