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Correct answer is (a) Ernst and SCHNARF

The EXPLANATION is: The true or false POLYEMBRYONY analogy is given by Ernst and Schnarf. It states that true or false of polyembryony DEPENDS on whether embryos ARISE from the same embryo sac or different sacs in the same ovule.

Correct answer is (d) horticulture

Easy EXPLANATION: Nucellar adventive polyembryony is of GREAT significance in horticulture. The adventive embryos PROVIDE uniform seedlings of PARENTAL type. Nucellar seedling of Citrus provides better CLONES than cuttings.

Correct option is (a) Ernst

Explanation: This was noticed for the first time by Leeuwenhoek (1719) in the SEEDS of orange. More often, as in MANY Citrus and Mango varieties some of the nucellar CELLS surrounding the embryo sac START dividing, protrude into the embryo sac and develop into the embryos.

The correct ANSWER is (d) WINKLER

The best explanation: The TERM apomixis was coined by Winkler in 1908. Ernst (1918) and Schnarf (1929) gave SIGNIFICANT inputs in the study of polyembryony. Mendel is the father of genetics.

The correct answer is (a) AMPHIMIXIS

To explain: Amphimixis is the formation of NEW individuals through the NORMAL process of SEXUAL reproduction by meiotic formation of GAMETES and their subsequent fusion during fertilization.

The CORRECT choice is (C) apomixis

Easy EXPLANATION: Apomixis is the PROCESS of formation of new individuals through asexual reproduction WITHOUT involving the formation and fusion of gametes.

The correct choice is (c) haustorium

Explanation: The suspensor cell may function LIKE a haustorium. The TERMINAL cell DIVIDES by another diagonal wall to form two cells. The top cell after several DIVISIONS forms the plumule and a single cotyledon.

Correct option is (a) micropylar

Best explanation: The zygote or oospore extends and then divides diagonally to FORM basal and TERMINAL CELLS. The basal cell (TOWARDS micropylar end) produces a big swollen, vesicular suspensor cell.

The correct option is (c) PROTODERM

Best explanation: Protoderm forms epidermis, procambium gives rise to STELE or VASCULAR strand and GROUND meristem produces CORTEX and pith.

Right CHOICE is (c) protoderm

Easy EXPLANATION: The octants (eight embryonic) cells divide periclinally (type of CELL division that occurs parallel to the cells) to produce a DERMATOGEN or an OUTER layer of protoderm. The inner cells differentiate into ground meristem (periblem) and procambium (plerome).

Right CHOICE is (a) SUSPENSOR

For explanation: The larger basal CELL in dicotyledons are termed as suspensor cell. The one TOWARDS the antipodal END is called as embryo cell or terminal cell.

Correct ANSWER is (a) True

For explanation: The embryo cell in DICOTS UNDERGOES two vertical divisions (quadrant stage) and one transverse division to form eight CELLS arranged in two tiers (octant stage) – epibasal (TERMINAL) and hypobasal (near the suspensor).

The correct CHOICE is (d) microplylar

The explanation: The changes that occur during the DEVELOPMENT of EMBRYO from ZYGOTE is defined as embryogeny. It takes place at the MICROPYLAR end of the embryo sac.

The correct choice is (B) coleorhiza

For explanation: SINCE monocotyledons have only ONE cotyledon, the LOWER end of the embryonal axis that is the radicle and root cap in MONOCOTS is enclosed within the coleorhiza.

Right choice is (a) Zygote

For EXPLANATION I WOULD say: Zygotes divide after endosperm formation. REASON being, zygote can not provide NUTRITION for itself. Endosperm is required to provide it with nutrition. It is an adaptation.

The correct option is (b) COLEOPTILE

Explanation: The PART of axis above the level of attachment of scutellum is called EPICOTYL. It has as SHOOT apex and few leaf primordia enclosed in a hollow foliar structure called coleoptile.

Right ANSWER is (b) True

Easy explanation: Though the seeds differ greatly, the early STAGES of embryo development (EMBRYOGENY) are SIMILAR in both monocotyledons and dicotyledons.

Right choice is (d) epicotyl

To explain: A TYPICAL DICOTYLEDONOUS embryo consists of an embryonal axis and two cotyledons. The part of embryonal axis above the LEVEL of cotyledons is CALLED epicotyl.

The CORRECT OPTION is (b) HYPOPHYSIS

The explanation is: The last cell of the SUSPENSOR at the end adjacent to the embryo is known as hypophysis. Hypophysis later gives rise to the radicle and ROOT cap.

Correct choice is (c) Embryogenesis

For explanation I WOULD SAY: Embryogeny is a process that follows FERTILIZATION. It is the process of DEVELOPMENT of a mature embryo from a zygote through cell division.

Correct OPTION is (a) True

Easiest EXPLANATION: It is meroblastic as it develops from a part of the zygote and ENDOSCOPIC as it develops towards the INTERIOR due to the suspensor.

The correct ANSWER is (B) monocots

Easy EXPLANATION: HELOBIAL occurs in monocots. It is an intermediate type of endosperm, an intermediate between cellular and nuclear TYPES of endosperms.

Correct choice is (b) True

The explanation: Traverse cytokinesis follows the first division of the primary ENDOSPERM NUCLEUS which forms TWO UNEQUAL cells-a large micropylar and a small chalazal.

Right answer is (a) proembryo

For explanation I would SAY: In simple words they are the cells FORMED after fertilization in the ovule before embryo formation. Initially the embryo is GLOBULAR and undifferentiated. Early embryo with RADIAL symmetry is called proembryo. It is transformed into embryo with the development of radicle, PLUMULE and cotyledons.

The correct CHOICE is (d) Nuclear

The explanation is: Nuclear ENDOSPERM is the most common type of endosperm. It is named so because it contains free NUCLEI in the beginning. For example, Coconut has multicellular endosperm (called coconut meal) in the outer PART and free nuclear as well as vacuolated endosperm (called coconut milk) in the centre.

Right answer is (a) cellular

The best I can explain: Every division of the primary endosperm nucleus is followed by cytokinesis. Therefore, endosperm becomes cellular from the very beginning. Commonly occurs in gamopetalous DICOTYLEDONS. After first transverse division, the SUBSEQUENT divisions are irregular. Endosperm tissue cell do not show REGULAR arrangement

The correct choice is (b) angiosperms

For explanation I would say: In angiosperms the endosperm is a special TISSUE which is formed as a result of VEGETATIVE FERTILIZATION, triple FUSION or fusion of a male gamete with diploid secondary nucleus of the central CELL.

Right answer is (a) free-nuclear

The explanation: Coconut water in TENDER COCONUTS, is a free nuclear endosperm that is made of nuclei (THOUSANDS) and the SURROUNDING white center is the cellular endosperm.

The correct choice is (B) PEN

Explanation: PEN-primary ENDOSPERM NUCLEUS is one of the most common type of endosperm development. The development occurs through successive nuclear division which gives rise to a free nuclei.

Correct choice is (c) EMBRYO

For explanation: Following DOUBLE fertilization, POST fertilization EVENTS begin. Events like endosperm FORMATION and embryo development, formation of seeds from ovules and ovary into fruit are classified as post fertilization events.

The correct OPTION is (d) vegetative fertilization

Best EXPLANATION: Second fertilization is called vegetative fertilization since as a consequence, a vegetative or nutritive tissue is formed to nourish the embryo. Vegetative fertilization is ALSO called triple fusion since three NUCLEI GET fused, two polar nuclei and one male gamete.

Right OPTION is (a) micropylar

The BEST I can explain: After entering the ovule, the pollen tube is attracted towards the micropylar end of the EMBRYO sac. The attractants are secreted by synergids or help CELLS. The pollen tube pierces one of the TWO synergids and bursts open into it.

Correct choice is (a) obturator

To ELABORATE: In the ovary the growth of the pollen tube is DIRECTED by ANOTHER TISSUE called obturator. The pollen tube enters the ovule, either through its micropyle (porogamy e.g., Lily), chalaza (chalazogamy e.g., Betula, Casuarina, Juglans regia) or the sides after piercing through the integuments (mesogamy, e.g. Cucurbita, Populus, Pistacea).

The correct option is (b) Triple fusion

Easiest EXPLANATION: The triple fusion initiates the FORMATION of endosperm by withdrawal of NOURISHMENT from the NUCELLUS and parent plant.

Right answer is (C) zygote

Explanation: Further growth of embryo sac OCCURS only when the zygote has been formed and primary ENDOSPERM NUCLEUS has been created by triple fusion.

Right option is (d) ANGIOSPERMS

To explain I would say: DOUBLE fertilization occurs only in angiosperms. The FEMALE gametophyte in angiosperms abruptly STOP their growth at 8 nucleate stages.

The correct choice is (c) Intraspecific incompatibility

For EXPLANATION I would say: The disadvantage of intraspecific incompatibility also known as self-incompatibility is that it does not allow the production of PURE lines. It only promotes CROSS POLLINATION.