NEET Biology Solved Question Paper 2011

In open vascular bundle, cambium is present between xylem and phloem of the same vascular bundle, eg, dicot stems.Due to the presence of cambium, secondary growth in stem occurs and secondary permanent tissues (secondary xylem, secondary phloem and vascular rays) are formed.

A eustachian tube connects the middle ear cavity with the pharynx. The eustachian the pressure on either side of the eardrum (tympanic membrane).

The squamous epithelium is made up of a single thin layer of flattened cells with irregular boundaries. They are found in the walls of blood vessels and air sacs of lungs and are involved in functions like forming a diffusion boundary

Kinetochores ar small disc -shaped proteinous structures present at the surface of the centromere. These structures serve as the sites of attachment of spindle fibres to the chromosomes that are moved into position at the centre of the cell.

The companion cells are specialised parenchyma cells, which are closely associated with sieve tube elements. The sieve tube elements and companion cells help in maintaining the pressure gradient in the sieve tubes. they also function in the loading of sucrose into sieve elements actively.

Many fungi belonging to the genera-Microsporum, Trichophyton and Epidermophyton are responsible for ringworms which is one of the most common infectious diseases in man. Microsporum is a member of the class- Deuteromycetes (Fungi imperfecti) of Kingdom - Fungi, Rhizopus (bread mould) is a member of the class - Zygomycetes (conjugation fungi) of Kingdom - Fungi.

During the passage of two electrons from one an electron carrier (NADH) to another on ETC, enough energy is liberated that pumps out three pairs of protons (H⁺) from the matrix (inner chamber) to the outer chamber (intermembrane space) of mitochondria.The accumulation of protons in intermembrane space results in their higher concentration than in the matrix creating a proton gradient (ΔpH) and electric potential across the membrane.

Trypsinogen is the precursor form or zymogen of the pancreatic enzyme trypsin. It is found in pancreatic juice, along with amylase. lipase and chymotrypsinogen. It is activated by enteropeptidase which is found in the intestinal mucosa, to form trypsin.

The notochord is a flexible, rod -shaped body found in the embryo of all chordates. It is composed of cells derived from the mesoderm. It represents the primitive axis of the embryo. In some chordates, it persists throughout life as the main axial support of the body (e.g. Amphibians), while in most vertebrates including humans it becomes the vertebral body of the vertebral column.

In frogs, the blood cells are RBC (Red Blood cells), WBC (White blood cells) or leucocytes and platelets. RBCs, also called erythrocytes, are nucleated and contain red coloured pigment namely haemoglobin.Human possesses enucleated RBC in a mature state.