The region near the middle of the Earth between the Tropic of Cancer and Tropic of Capricon is considered as the Tropic region. This region receives the most amount of solar energy which leads to better productivity and higher species diversity Also, the seasonal variations in such regions are low and environment mainly remains the same supporting high species richness and promoting niche specialization. Tropical rain forests used to cover more than 14 percent of the Earth's surface. Now due to human activities S, uman activities leading to destruction of habitat and pushing many species to the brink of extinction has tropical rainforests cover no more than 6 percent.

Seeds will be produced without testa if the outer integument of the ripened ovule is removed experimentally.

After the fertilisation in plants, the ripened ovule develops into the seed while the ripened ovary develops into the fruit. The outer integument of the ovule develops into the outer coat of seed known as testa while the inner integument develops into the inner seed coat known as tegmen. Removing the outer integument will render seeds without the outer coat known as testa.

● The pericarp is a fruit wall that is developed from the walls of the ovary.

● When fruit develops from a source other than ripened ovary, it is termed as false fruit.

When H₂O₂ is added to an acidified solution of a dichromate, Cr₂O₇^2-, aO deep blue coloured complex, chromic peroxide, CrO₅ or CrO(O₂)₂ is formed.

Cr₂O₇^2-+2H⁺+4H₂O--->2CrO(O₂)₂+5H₂O

This deep blue coloured complex.

The oxidation state of Cr is +6 due to the presence of two peroxide linkages which can be calculated as Cr peroxide normal

X+(-1)4 + (-2) = 0

X-6 = 0

X = +6

In mammals, the testes occur in scrotal sacs outside the viscera because of the requirement of low temperature for spermatogenesis. The testes are situated outside the abdominal cavity within a pouch called scrotum. The scrotum helps in maintaining the low temperature of the testes (2–2.5°C lower than the normal internal body temperature), which is necessary for spermatogenesis. 

The slightly cooler temperature of the scrotum is necessary for the development of normal sperm. So, the testes start their development in the abdominal cavity and descend into the scrotal sacs during the 7th month of the fetal life, in presence of testosterone hormone.

Some prokaryotes like photosynthetic bacteria and blue-green algae possess small membrane lined chromatophores, which are similar to but chemically simpler than the chlorophyll of plants.

• Haemophilia is an inherited bleeding disorder where the blood doesn't clot properly as the blood does not have enough clotting factors. It is C-linked recessive disorder related to a deficiency of antihaemophilic globulin protein.
• Cretinism is a condition characterised by physical deformity and learning difficulties that are caused by congenital thyroid deficiency. So it is a disease of the endocrine system which is non-inheritable.
• Cystic fibrosis is an autosomal recessive disorder in which fibrous cyst formation takes place in lungs and pancreas. The gene for the disease is present on Chromosome 7.
• Thalassemia is a quantitative disease. It is a hereditary hemolytic disease caused by faulty hemoglobin synthesis, widespread in African and Asian countries.

Bones are divisible into four classes: Long, Short, Flat, and Irregular. The long bones are found in the limbs, and each consists of a body or shaft and two extremities. Some of the irregular bones are vertebrae, sacrum, coccyx, temporal, sphenoid, maxilla, palatine, inferior nasal concha, mandible and hyoid. Flat bones are composed of two thin layers of compact tissue enclosing between them variable quantity of cancellous tissue. Where a part of the skeleton is intended for strength and compactness combined with limited movement, it is constructed of a number of short bones, as in the carpus and tarsus.

The pituitary releases LH when the level of blood testosterone falls, which has positive feedback with the hypothalamus and the anterior pituitary gland.