Biology Test 153

The correct combination is a- endodermis, b-conjunctive tissue, c-protoxylem, d-metaxylem, e-phloem, and f-pith.

Parenchyma tissue particularly really presents between xylem and phloem is called Conjunctive tissue, which for all intents and purposes kind of shows that tetrarch stele essentially mostly is present, generally, for the most part, means stele with four xylem strands, showing how in the stele of dicot root, the outermost part is the pericycle, and inner vascular bundles medulla, conjunctive tissue is present, which is fairly significant.

So, in the pretty generally transverse section of dicot root stele shows, outer pericycle, generally really followed by vascular bundles, conjunctive tissue, and medulla, so parenchyma tissue generally actually present between xylem and phloem essentially mostly is called Conjunctive tissue, which for the most part shows that tetrarch stele is present, for all intents and purposes generally means stele with four xylem strands, showing how in the stele of dicot root, the outermost part is the pericycle, and inner vascular bundles medulla, conjunctive tissue is particularly present.

Hence, the correct option is (D).

Ruminate endosperm is commonly found in seeds of Annonaceae (Areca nut).

Seeds are the product of the ripened ovule after the fertilization process. The embryo is made from the zygote and the seed coat from the ovule integuments. So, as we discussed seed, let 's understand about ruminate endosperms. Ruminate endosperm in which the endosperm is dissected in the growth of the seed coat. Ruminate endosperm forms when the seed coat intrudes inward via meristematic growth. Ruminate endosperm is frequently present in the Annonaceae family seeds. Some of the examples of families are Rubiaceae, Aceraceae, Aristolochiaceae, Palmaceae. The testa of the seed coat gets infolded into the endosperm. It is found in custard apple, berries, and syncarps. Seeds are one to many per pistil. They have a fleshy and usually brightly colored cover and they are oily. The ruminate endosperm is the nutritive tissue surrounding the embryo.

Hence, the correct option is (D).

The presence of auxins in a solution could be tested by avena sativa stem tip test.

Avena sativa stem tip test or Avena curvature test is a diagnostic test for auxin. In this test auxins accumulate on the dark side (not exposed to light) of oat coleoptile and cause more growth on the darker side than the exposed side. Thus, causing a curvature stem towards the source of light.

Hence, the correct option is (A).

Indole acetic acid is a carboxylic acid in which the carboxyl group is attached.

Indole-3-acetic acid (IAA) is the most common, naturally-occurring, plant hormone of the auxin class. It is the best known of the auxins and has been the subject of extensive studies by plant physiologists. Chemically, indole acetic acid is a carboxylic acid in which the carboxyl group is attached through a methylene group to the C-3 position of an indole ring. In appearance, indole acetic acid is a colorless solid. Indole acetic acid is an auxin. Auxins are growth-promoting phytohormones. They are also called rooting hormones because they stimulate the growth of roots in plants, especially in tissue culture experiments. Auxins inhibit the growth of axillary buds. Hence, they have an inhibitory effect on the growth of the stem. The inhibition of the growth of axillary buds by auxins is called apical dominance.

Hence, the correct option is (B).

In Rhizopus, tubular thread-like structures bearing sporangia at their tips are called hyphae.

Hyphae in fungi are filamentous structures which branch out and spread below the surface of a substratum like bread. During their life cycle a hyphae may rise erect above the surface, with it's content at the tip forming a bulge. This bulge forms the sporangium. Spores are formed in the sporangium and is a mode of asexual reproduction.

Hence, the correct option is (B).

The first scientist associated with the discovery of auxins in plants is Darwin.

Charles Darwin (1880) the great evolutionist had hypothesized the presence of growth substances in plants. In his book, 'The power of movement in plants', Darwin has described the experiments concerning the growth movements in canary grass. He had noticed the unilateral bending of the shoot tip (coleoptile) towards the source of light. Charles Darwin and his son Francis discovered in 1880, that the phototropic stimulus is detected at the tip of the plant. The Darwins used grass seedlings for their experiments. When grass seeds germinate, the primary leaf pierces the seed coverings and the soil while protected by the coleoptile, a hollow cylindrical sheath that surrounds it. Once, the seedling has grown above the surface, the coleoptile stops growing and the primary leaf pierces it. The Darwins found that the tip of the coleoptile was necessary for phototropism but that the bending takes place in the region below the tip.

Hence, the correct option is (C).

The sequence of development of embryo sac is Archesporium → megaspore mother cell → megaspore → embryo sac.

A single hypodermal cell of the nucellus in the ovule or megasporangium, called the archesporium cell behaves as a megaspore mother cell. A single megaspore mother cell matures within the ovule. Through meiosis, it forms four haploid megaspores and this process is called megasporogenesis. Out of these four megaspores, only one remains functional, and the rest three degenerate. This functional megaspore then develops into an embryo sac or female gametophyte by the process of megagametogenesis. The nucleus of the functional megaspore divides three times by mitosis to form 8 nuclei which then get organized to form 7-celled and 8-nucleate embryo sac.

Hence, the correct option is (C).

Endodermis part of dicot root is made up of cells with suberin deposition in tangential as well as radial walls.

The inner most part of the cortex in root and dicot stem is endodermis. It is single layered. Cells are barrel shaped and thick walled. On the radial walls and tangential walls, ligno suberised thickenings are present. These are called Casparian thickenings. Some of the endodermal cells lack casparian bands. These are called passage cells. These cells are present opposite to the protoxylem cells. Endodermis acts as check point, and prevents the outflow of water and minerals from the stele into cortex, and also acts as a barrier in the inflow of water and mineral from cortex and stele.

Hence, the correct option is (B).

Lysosome of organelle, which is surrounded by a single layered wall.

Lysosomes are small vesicles containing hydrolyzing enzymes and surrounded by a single layered lipid membrane of up to 100nm in thickness. Whereas mesosome and centrosome are the  organelles without membrane, Nucleus is the membrane bound structure in cells.

Hence, the correct option is (A).

In plant cell vacuole is membrane bound structure which stores various substance and excrete them.

Vacuoles are membrane-bound organelles that can be found in both animals and plants. In a way, they're specialized lysosomes. That is to say that their function is really to handle waste products, and by handle, mean take in waste products and also get rid of waste products. Sometimes the waste product is water, and therefore a vacuole would have as its function to maintain the balance of water inside and outside a cell. Sometimes a vacuole's function is to get rid of harmful toxins or to clear the extracellular space of those harmful toxins by bringing them into the cell for conversion, for chemical conversion into more safe compounds. The vacuoles are quite common in plants and animals, and humans have some of those vacuoles as well. But vacuole also has a more generic term, meaning a membrane-bound organelle that's lysosome-like.

Hence, the correct option is (A).