NEET 2023 Biology Question Paper with Answer and Solution

Option (4) is the answer because, basophils secrete histamine, serotonin, heparin etc. and are involved in inflammatory response.

Option (3) is not the answer because, basophils are granulocytes.

Option (1) is not the answer because, neutrophils are the most abundant cells $(60-65 \%)$ of the total WBCs whereas basophils are least $(0.5-1 \%)$ abundant of all WBCs.

Option (2) is not the answer because, monocytes have a kidney-shaped nucleus.

(A) - Statement $A$ is incorrect: Tetrad formation occurs during the Zygotene stage of Prophase-$I$.
- Statement $B$ is correct: During Anaphase (specifically Anaphase-$II$ or Mitotic Anaphase),the centromeres split,allowing sister chromatids to separate and move toward opposite poles.
- Statement $C$ is incorrect: Terminalization of chiasmata occurs during the Diakinesis stage of Prophase-$I$.
- Statement $D$ is correct: During Telophase,the nuclear envelope reforms,and the nucleolus,Golgi complex,and Endoplasmic Reticulum $(ER)$ reappear.
- Statement $E$ is incorrect: Crossing over occurs between non-sister chromatids of homologous chromosomes during the Pachytene stage.
Therefore,statements $B$ and $D$ are correct.

Option (4) is the answer because,

In cockroach, excretion is brought about by Malpighian tubules, fat body, nephrocytes and urecose glands.

Urecose glands are present in male cockroach of some species. They synthesise uric acid. Nephrocytes are large, colourless, ovoid, binucleate cells attached to the dorsal diaphragm in the body cavity. Fat body accumulates, produces and stores uric acid.

Phallic gland is the structure of male reproductive system of cockroach and it secretes the outer layer of spermatophore. Collaterial gland is the structure of female reproductive system of cockroach and it secretes the hard egg-case or ootheca around fertilised eggs.

(D) The correct answer is $D$ $(A-II, B-I, C-IV, D-III)$.
- Mast cells are found in the areolar connective tissue,which also contains fibroblasts and macrophages.
- The inner surface of bronchioles is lined by ciliated epithelium,which helps in moving mucus and particles.
- Blood is classified as a specialised connective tissue because it consists of a fluid matrix (plasma) and formed elements.
- The tubular parts of the nephron (such as the proximal convoluted tubule) are lined by cuboidal epithelium,which is involved in absorption and secretion.

(C) Statement $A$ is incorrect because muscle bundles are held together by a collagenous connective tissue layer called fascia,not fascicle. The bundles themselves are called fascicles.
Statement $B$ is correct because the sarcoplasmic reticulum of muscle fibres is indeed a storehouse of calcium ions,which are essential for muscle contraction.
Statement $C$ is correct because the striated appearance of skeletal muscle fibres is due to the regular distribution pattern of actin and myosin proteins.
Statement $D$ is incorrect because the portion of the myofibril between two successive $Z$-lines is considered the functional unit of contraction,called a sarcomere,not the $M$-line.
Therefore,only statements $B$ and $C$ are correct.