Which of the following diseases is caused by a protozoan transmitted by the tsetse fly? MCQ with Answer and Explanation

Explanation:
Lateral meristems, namely vascular cambium and cork cambium, are responsible for secondary growth, increasing the girth of stems and roots in dicots and gymnosperms. Apical meristem causes primary growth in length, intercalary meristem elongates nodes, ground meristem forms ground tissue.

Explanation:
Aneuploidy is a chromosomal abnormality resulting from nondisjunction, the failure of homologous chromosomes or sister chromatids to separate properly during cell division. Down syndrome is a genetic disorder caused by the presence of an extra copy of chromosome 21 (trisomy 21). Turner syndrome is a sex chromosome anomaly in females characterized by the karyotype 45, X0, not 47, XXY (which is Klinefelter syndrome). Thus, statements 1 and 2 are correct.

Explanation:
The cohesion-tension theory, primarily proposed by Dixon and Joly (and later supported by Denison), is the most widely accepted mechanism for the ascent of sap in tall trees. It relies on the physical properties of water. Transpiration from the leaves creates a negative pressure (tension) in the xylem. This tension pulls the water column upwards. The water column remains unbroken due to the high cohesive force between water molecules (hydrogen bonding) and the adhesive force of water to the hydrophilic walls of the xylem vessels and tracheids. This creates a continuous, passive pull from the top.