The structure in the kidney that concentrates urine is the: MCQ with Answer and Explanation

Explanation:
Approximately 97% of O₂ is transported bound to hemoglobin (as oxyhemoglobin), while only 3% is dissolved in plasma. Each hemoglobin molecule can bind four O₂ molecules cooperatively. CO₂ is mainly transported as bicarbonate (70%), carbaminohemoglobin (23%), and dissolved (7%). The affinity of hemoglobin for O₂ is influenced by pH, CO₂, and temperature (Bohr effect).

Explanation:
When both parents are heterozygous (Tt × Tt), the offspring genotypes are TT (25%), Tt (50%), and tt (25%). Since tall (T) is dominant over dwarf (t), both TT and Tt are tall, resulting in 3 tall : 1 dwarf phenotypic ratio. The genotypic ratio is 1:2:1. 9:3:3:1 is the dihybrid phenotypic ratio. 1:1 ratio is seen in test cross (Tt × tt).

Explanation:
Meiosis involves two divisions reducing the chromosome number from diploid (2n) to haploid (n), producing gametes (sperm and egg). Mitosis maintains the chromosome number and produces identical somatic cells. Amitosis is direct nuclear division, budding is asexual reproduction. Meiosis ensures genetic diversity.