NEET SECTION - A [BOTANY - MCQ]

A

D. reduction
Explanation:
During reduction stage of Calvin cycle, a glucose molecule is formed through a series of reactions. Each molecule of 3PGA is phosphorylated using ATP and 1, 3-bisphosphoglyceric acid is formed. Each molecule of 1,3-bisphosphoglyceric acid is converted into glyceraldehyde 3-phosphate (G3P) using NADPH. Glyceraldehyde 3-phosphate is converted into one molecule of glucose through a series of reactions that are reversal of glycolysis. So, this is also called glycolytic reversal.

B

A. Statement (c) is correct.
Explanation:
Since oxygen is evolved in reaction P, the equation represents oxygenic photosynthesis which occurs in green plants and cyanobacteria whereas no oxygen is evolved as per equation Q, this is anoxygenic photosynthesis which occurs in photosynthetic bacteria which do not use water an electron donor and forms sulphur instead of oxygen.

C. Cell plate formation
Explanation:
Cytokinesis occurs by a special mechanism in higher-plant cells in which the cytoplasm is partitioned by the construction of a new cell wall, the cell plate, inside the cell. The position of the cell plate is determined by the position of a preprophase band of microtubules and actin filaments.

C. Prophase
Explanation:
Prophase is the first phase of mitosis, the process that separates the duplicated genetic material carried in the nucleus of a parent cell into two identical daughter cells. In prophase condensation of chromosomal material (Chromosomes form), centriole begins to move towards opposite poles of the cell, Initiation of the assembly of the mitotic spindle, the microtubules.

A

A

D. Crotalaria juncea
Explanation:
Green manure is an organic substance that increases the fertility of the soil. Crotalaria juncea is grown into and ploughed to a soil that decomposes and increases the fertility.

C. Biological process
Explanation:
Secondary sewage treatment is mainly biological process.

A

A

C. Leptotene
Explanation:
Leptotene also known as leptonema is the first stage of prophase I during which individual chromosomes begin to condense into long strands within the nucleus which are loosely interwoven. However, the two sister chromatids are still so tightly bound that they are indistinguishable from one another. They possess a string of swollen areas called chromomeres.

D. Malignant tumours may exhibit metastasis.
Explanation:
Tumouris of two types: benign and malign.Malign or malignant tumour exhibits metastasis.It is the phenomenon in which cancer cells spread to distant sites through body fluids to develop secondary tumour.

C. Dried leaves and flowers of Cannabis sativa
Explanation:
Dried leaves and flowers of Cannabis sativa

B. (i), (ii), (iii) and (iv)
Explanation:
Good health is maintained by balanced diet, personal hygiene, regular exercise, awareness about disease, vaccination against infectious diseases, proper disposal of wastes, control of vectors and maintenance of hygienic food and water resources.

C

A

A. Across the cell membrane
Explanation:
Integral proteins that go through the membrane are called transmembrane proteins. They have hydrophobic regions within the interior of the membrane and hydrophilic regions at the outer membrane surface.

A.This structure also found in eukaryotes
Explanation:
Mesosome which is formed by the extensions of the plasma membrane into the cell. These extensions are in the form of vesicles, tubules and lamellae. They help in cell wall formation, DNA replication and distribution to daughter cells. They also help in respiration, secretion processes, to increase the surface area of the plasma membrane and enzymatic content.

B. Splicing
Explanation:
Splicing is the removal of intervening sequences of introns and the joining of expressing sequences or exons in a specific order during transcription.

D. polysome.
Explanation:
A polyribosome (or polysome) is a complex of an mRNA molecule and two or more ribosomes that act to translate mRNA instructions into polypeptides.

D.Formation of abnormal ova in the mother
Explanation:
The karyotype XXX represents that it is a female which results from the fusion of a sperm with X chromosome with an ovum with two X chromosomes. So, abnormal ova are produced in them

A

D. Monocotyledonous stem
Explanation:
Closed vascular bundles are scattered and surrounded by bundle sheath embedded in large parenchymatous ground tissue is characteristic of monocot stem. The vascular bundles are open, conjoint, and arranged in a ring with inconspicuous pith in the dicot stem. In roots, the vascular tissues are arranged radially.

C. Monocot stem - 1 - Epidermis, 2 - Hypodermis, 3 - Vascular bundles, 4 - Phloem, 5 - Xylem, 6 - Ground tissue
Explanation:
The diagram is of transverse section of a Monocot stem - 1 - Epidermis, 2 - Hypodermis, 3 - Vascular bundles, 4 - Phloem, 5 -Xylem, 6 - Ground tissue.

B. (iii) and (v)
Explanation:
(iii) and (v) statements are incorrect.
The corrected statements are given below:
• In basal placentation, the placenta develops at the base of the ovary and a single ovule is attached to it.
• In mustard and argemone, Parietal placentation is present.

C.

Presence of tepals and epitepalous stamens in a flower can be denoted by

D. All of these
Explanation:
On the basis of megaspores contributing to the development of embryo sac, a number of mitotic divisions occur in the functional megaspore. There are three types of embryo sacs:
i. Monosporic embryo sac: In this type of embryo sac, out of the four megaspores, one megaspore at the chalazal side takes part in the formation of the embryo sac. The nucleus divides three times to form 8 nuclei. This type is called the Polygonum type.
ii. Bisporic embryo sac: In this type of embryo sac, two megaspores take part in the formation of the embryo sac. The nucleus of two megaspores undergo two mitotic divisions and the resulting embryo sac is 8 nucleate.
iii. Tetrasporic embryo sac: In this type of embryo sac, all four megaspores take part in the formation of the embryo sac. All the four haploid nuclei remain in a common cytoplasm and forming a coenomegaspore. The final organization of the embryo sac is 8 -nucleate. Hence, the 8-nucleate embryo sac can be monosporic, bisporic, and tetrasporic.

C

C. All of these
Explanation:
A flagellum is a long, whip-like structure that helps some single-celled organisms move. It is composed of microtubules. They help propel cells and organisms in a whip-like motion. The flagellum of eukaryotes usually moves with an " S " motion and is surrounded by the cell membrane. Red algae, Blue-Green algae, and higher plants lack flagella in their cells.

C. Directly from a spore
Explanation:
When a moss first grows from the spore, it starts as a germ tube which lengthens and branches into a filamentous complex known as a protonema, which develops into a leafy gametophore, the adult form of a gametophyte in bryophytes. Moss spores germinate to form an algae-like filamentous structure called the protonema.

D. Salvinia-Prothallus
Explanation:
Prothallus is the gametophyte in most of the pteridophytes in which both male and female sex organs called antheridia and archegonia are present. But salvinia is heterosporous and produces male and female gametes on different plant so it do not possess prothallus.

B. Presence of vessel elements and absence of archegonia
Explanation:
Members of order Gnetales posses vessels and show absence of archegonia.

B

C. one male gamete and two polar nuclei.
Explanation:
Endosperm develops from primary endosperm cell (PEC) which is formed from the fusion of two polar nuclei of the central cell with a male gamete.

C. Both wall of sporangium and sporogenous cells
Explanation:
Both wall of sporangium and sporogenous cells

A.Trees, shrubs, and herbs
Explanation:
Aristotle classified plants on the basis of their morphological characters into trees, shrubs, and herbs.

D. Fission
Explanation:
Bacteria increase their cell number or individuals mainly by binary fission. Rest of the processes are mostly used during unfavourable conditions.

A.This species was first described by Linnaeus
Explanation:
Mangifera indica Linn indicates that this species was first described by Linnaeus as in binomial nomenclature, the name of author appears after the species name. This method of mentioning the author's name is called a citation.

A. William Harvey
Explanation:
William Harvey discovered of the circulation of the blood.

D. Sapindales
Explanation:
Mango is included in Order Sapindales.