Traits that are determined by a single gene are of five main types: Y-linked, X-linked dominant, X-linked recessive, autosomal d
ominant, and autosomal recessive. How many of these modes of inheritance are POSSIBLE for this pedigree? Assume the gene is completely penetrant, and there is NO new mutations.
For the Y-linked gene, there is only one mode of inheritance. For X-linked dominant and recessive genes, there are two modes of inheritance. For the autosomal dominant and recessive, it depends on the origin of the genes. For homozygous dominant and homozygous recessive parents, there is only one mode of inheritance.
Autosomal dominant is the only fit for inheritance,
considering that it a person will be able to inherit a condition from the
parent. And since there is no mutation in it, a NEW mutation can
happen in the genes even though there is no history of it in the family.
In framing farmers use pesticides kill crop pests. But pesticides can have unexpected and unwanted effects on other organisms too. These chemicals harm other species living around the farm. Besides, farmers often use chemical fertilizers to increase the crop productivity but excess use of fertilizers can cause water pollution. Polluted water can kill fish and other aquatic organisms. In this way farming affects biodiversity.
Ecologists and paleontologists say that Earth is now experiencing another mass extinction. One-quarter of all mammals are endangered. But unlike some past extinctions this one is not caused by a single chance event such as an asteroid impact.