Alginic acid(or algin or alginate) is an anionic polysccharide distributed widely in the cell walls of many brown algae (Phaeophyceae). It is a phycocolloid which is obtained commercially from Laminaria, Macrocystis, Nereocystis, Fucus, Sagrassum etc.

A hiccup can be described as a jerky incomplete inspiration. It is an involuntary contraction of the diaphragm that may repeat several times per minute. In medical terms, it is known as synchronous diaphragmatic flutter (SDF).

In C₄ Plants, initial fixation of carbon dioxide occurs in mesophyll cells. The primary acceptor of CO₂ i.e. phosphoenol pyruvate (PEP) combines with CO₂ in the presence of PEP carboxylase or PEPcase to form oxaloacetic acid, which is the first stable carbon dioxide fixation product in C₄ pathway.

Cholesterol is a precursor of most steroid hormones like progesterone, estradiol, aldosterone, cortisol etc. Cholesterol forms vitamin D on UV exposure  and it also helps in forming bile salt

Roots in Cycas are of two types- normal and coralloid roots. Coralloid roots are irregular, negatively geotropic, dichotomously branched coral like roots which do not possess root hairs and root caps. Coralloid roots have a symbiotic association with blue-green algae like Nostoc and Anabaena species

Matured mammalian RBCs do not have cell organelles including nucleus, Golgi bodies, mitochondria, ribosomes, centrioles and endoplasmic reticulum. It increases the surface area of RBCs and enables them to contain more haemoglobin. In the absence of cell organelles, the consumption of oxygen is very low and thus anaerobic respiration occurs in RBCs. Mature RBCs cannot replicate and cannot synthesise RNA as they do not possess machinery required (e.g., various enzymes) for replication and RNA synthesis.

Hypothalamus is connected to the anterior lobe of pituitary gland by hypophysial portal veins. The latter carry blood containing neurohormones (releasing factors) from the hypothalamus to the anterior lobe of the pituitary.

Ascending limb of loop of Henle is impermeable to water. It does not reabsorb water, rather sodium, potassium, magnesium and chloride are reabsorbed and therefore the filtrate becomes hypotonic to blood plasma

Adenine (A), guanine (G), cytosine (C), thymine (T) and uracil (U) are all nitrogenous bases, whereas cytidine is a nucleoside i.e., a combination of a nitrogenous base (cytosine) with a pentose sugar (ribose).