<u>Answer:</u>
<em>It is advantageous to have lesser number of bones in the pectoral girdle.</em>
<u>Explanation:</u>
Pectoral girdle is made up by the bones that connect the upper limbs to the appendicular skeleton which includes all the limb bones. Pectoral girdle in humans is made up of two bones. They are clavicle (collar bone) and scapula. The pectoral girdle allows the free movement of upper limbs.
The bones of pectoral girdle are not as massive as the bones of pelvic girdle since it doesn’t have the function of support. Lesser number of bones in pectoral girdle makes movement of upper limbs more free.
With the sequence of the gene-coding regions of the human genome in hand and the development of newer sequencing methods, scientists are able to
1. develop new forensic tests that can help in the identification of the convict.
2. diagnose genetic diseases before their onset.
3. develop customised medicines based on the genetic profile of the patient.
4. therapeutically target the cancer causing genes (oncogenes) in the patients.
5. understand the inheritance of genes especially the rare mutations in a population.
Answer:
Cyanobacteria were photosynthetic and slowly changed the earth's atmosphere from CO2 rich to O2 rich. Photosynthetic cyanobacteria evolved by 3.5 billion years ago and greatly modified earth's atmosphere.
