6-C (breaks off)
7-C(they secrete acid that breaks away rocks)
Answer:
Option A
Explanation:
Thyroid is primarily caused by lack of iodine but there are other reasons as well that lead to increased size of the thyroid gland. Some of these reason is
a) over- or underproduction of thyroid hormones
b) Nodules in the glans
Some times, due to overstimulation immune system itself attack the thyroid gland thereby producing excess thyroxine and hence causing the thyroid to swell
Thus, Option A is correct
Mainly by nitrogen-fixing bacteria in the soil and oceans
A heterozygous individual is someone who has one recessive and one dominant trait
ex: (Dh). D- black hair. d- blonde hair
The phenotype will be the one that belongs with the dominant trait (D) so the phenotype would be black hair.
hope that helps
Extraction of aluminium metal takes place in three main stages¿mining of bauxite ore, refining the ore to recover alumina and smelting alumina to produce aluminium. Bauxite is mined by surface methods (open-cut mining) in which the topsoil and overburden are removed by bulldozers and scrapers.