In the human respiratory system, the Haldane effect refers to: MCQ with Answer and Explanation

Explanation:
An operon is a functional unit of DNA in prokaryotes containing a cluster of genes under the control of a single promoter, transcribed as a single mRNA. Example: lac operon. It includes operator, promoter, and structural genes. Operons allow coordinate regulation. Eukaryotes generally lack operons.

Explanation:
A mature embryo sac (female gametophyte) in angiosperms is 7-celled but 8-nucleate: 3 antipodal cells (3 nuclei), 2 synergids (2 nuclei), 1 egg cell (1 nucleus), and 1 central cell with 2 polar nuclei. Thus total 8 haploid nuclei. The central cell is homodiploid (2 polar nuclei). Double fertilization involves these nuclei. This is typical of Polygonum type of development.

Explanation:
Robert Koch, a German physician and microbiologist, formulated Koch's postulates in the late 19th century. These four criteria are designed to establish a causal relationship between a specific microbe and a specific disease. The postulates require that the microbe must be found in all cases of the disease, isolated and grown in pure culture, cause the disease when inoculated into a healthy susceptible host, and be re-isolated from the experimentally infected host.