The fleshy receptacle of syconus of fig encloses number of
Achenes
Samaras
Berries
Mericarps
A.
Achenes
Which of the following floral parts forms pericarp after fertilization?
Nucellus
Outer integument
Ovary wall
Inner integument
C.
Ovary wall
After fertilization, the mature, ripened ovary develops into fruit. The ovary wall forms the covering of the fruit called fruit wall or pericarp. Some other post fertilization changes also occur like nucellus develops into perisperm, ovules develop into seeds, outer integument forms testa, inner integument forms tegmen, etc.
Which one of the following is linked to the discovery of bordeaux mixture as a popular fungicide?
Bacterial leaf blight of rice
Downy mildew of grapes
Loose smut of wheat
Black rust of wheat
B.
Downy mildew of grapes
Chromosomes are arranged along the equator during
Prophase
Metaphase
Anaphase
Telophase
D.
Telophase
In plant cells, during metaphase chromosomes line up around the equator of the spindle and attached by their centromere to the spindle fibres (microtubules). In animal cells, during metaphase, smaller chromosomes are usually central in position with larger ones peripheral in position.
Width of the DNA molecule is
15 Ao
20 Ao
25 Ao
34 Ao
B.
20 Ao
The 3-D structure of DNA is represented by a double helix, in which each turn has a diameter of 34 Å and contains 10 base pairs at a distance of 3.4 Å. The width of DNA molecule is 20 Å.
Development of an embryo without fertilization is called as
Apomixis
Polyembryony
Parthenocarpy
Parthenogenesis
D.
Parthenogenesis
Parthenogenesis (virgin origin) is the development of an embryo from an unfertilized egg or if a spermatozoan does penetrate the egg, there is no union of male and female pronuclei. It is found in many plants (dandelions and hawk weeds) and (aphids and honey bees).
A fern differs from a moss in having
Swimming archegonia
Swimming antherozoids
Independent gametophytes
Independent sporophytes
D.
Independent sporophytes
Fern (pteridophyte) differs from a moss s(bryophyte) in having independent gametophyte, while in moss the sporophyte is simpler than the gametophyte and remains attached to the parent gametophyte throughout its life. This sporophyte is dependent upon gametophyte partially or wholly for its nutrition.
Female cone of Pinus is a
Modified needles
Modified long shoot
Modified dwarf shoot
Modified scale
D.
Modified scale
The female cone of Pinus is formed by the aggregation of megasporophylls, which bear ovules. Each megasporophyll consists of a lower bract scale and a larger upper ovuliterous scale.
Unisexuality of flowers prevents
Autogamy, but not geitonogamy
Both geitonogamy and xenogamy
Geitonogamy, but not xenogam
Autogamy and geitonogamy
A.
Autogamy, but not geitonogamy
Prothallus of the fern produces
Spores
Gametes
Both (a) and (b)
Cones
C.
Both (a) and (b)
Prothallus is a small, flattened, multicellular structure that represents the independent gametophyte generation of a fern. The prothalli bear antheridia (male sex organs) and archegonia (female sex organs) which produce male and female gametes, respectively.