All Free Biology MCQs with Answers

• A. Stolon
• B. Offset
• C. Runner
• D. Sucker

Explanation: Offset is a method of vegetative propagation where new plantlets develop at the base of the parent plant and can be separated to grow…

• A. Offset
• B. Rhizome
• C. Sucker
• D. Runner

Explanation: Mint plants can undergo vegetative propagation through rhizomes. Rhizomes are underground stems that produce new shoots and roots…

• A. Geitonogamy, but not Xenogamy
• B. Autogamy and Geitonogamy
• C. Autogamy, but not Geitonogamy
• D. Both Geitonogamy and Xenogamy

Explanation: Unisexuality of flowers prevents autogamy (self-pollination) and geitonogamy (pollination between flowers of the same plant), as both…

• A. Pollen exine
• B. Leaf cuticle
• C. Cork
• D. Wood fibre

Explanation: Pollen exine is resistant to enzyme action because it is a tough, outer layer of a pollen grain that protects it from environmental…

• A. Generative cell
• B. Vegetative cell
• C. Microspore mother cell
• D. Microspore

Explanation: In angiosperms (flowering plants), male gametes (sperm cells) are formed by the division of the generative cell.

• A. Have more than 90 percent similar genes
• B. Look similar and possess identical secondary metabolites
• C. Have same number of chromosomes
• D. Can reproduce freely with each other and form seeds

Explanation: Plants of the same species can be conclusively identified when they can reproduce freely with each other and produce viable offspring…

• A. Male gamete
• B. Egg
• C. Pollen grain
• D. Microspore mother cell

Explanation: A pollen grain is surrounded by a callose wall during its development. This callose wall helps protect the pollen grain as it matures and…

• A. Treating the plants with phenylmercuric acetate
• B. Removing androecium of flowers before pollen grains are released
• C. Treating the plants with low concentrations of gibberellic acid and auxins
• D. Raising the plants from vernalized seeds

Explanation: Parthenocarpy is the development of fruit without fertilization. By removing the androecium (the male reproductive organs, including the…

• A. Coleoptile
• B. Coleorhiza
• C. Scutellum
• D. Prophyll

Explanation: In a cereal grain, the single cotyledon of the embryo is represented by the scutellum.

• A. Nucellus or integuments
• B. Zygote
• C. Synergids or antipodals in an embryo sac
• D. Accessory embryo sacs in the ovule

Explanation: Normal type of sexual reproduction having two regular features, i.e., meiosis and fertilization, is called amphimixis.

• A. Amphitropous
• B. Circinotropous
• C. Atropous
• D. Anatropous

Explanation: Depending upon position of micropyle in relation to chalaza, ovules are of 6 types in angiosperms.

• A. Tetraploidy
• B. Pentaploidy
• C. Diploidy
• D. Triploidy

Explanation: Endosperm is formed due to fusion of the haploid male gamete with the polar nucleus of the embryo sac.

• A. Hemitropous
• B. Campylotropous
• C. Anatropous
• D. Orthotropous

Explanation: In hemianatropous or hemitropous ovule, the nucellus and integuments are at right angles to stalk or funiculus so that the ovule becomes…

• A. Reception of pollen by stigma
• B. Formation of pollen
• C. Development of anther
• D. Opening of flower bud

Explanation: Anthesis is the process of opening floral buds. The reception of pollen by stigma is called pollination.

• A. Only the wall of the sporangium
• B. Both wall and the sporogenous cells
• C. Wall and the tapetum
• D. Only tapetum and sporogenous cells.

Explanation: In flowering plants, archesporial cells are vertical rows of hypodermal cells at four angles of anther.

• A. Pectocellulose
• B. Callose
• C. Cellulose
• D. Sporopollenin

Explanation: Each microspore or pollen is having a two layered wall. Outer layer is thick tough cuticularised called exine, which is chiefly composed…

• A. Upward
• B. Downward
• C. Right
• D. Left

Explanation: Anatropus ovule is the most common type of ovule found in angiosperms. Here the body of the ovule gets inverted and micropyle is on lower…

• A. Nucellus
• B. Integuments
• C. Zygotic embryo
• D. Fertilized egg

Explanation: Presence of more than one embryo inside the seed is called polyembryony. It is more common in gymnosperms than angiosperms.

• A. Salvia
• B. Bottle brush
• C. Vallisneria
• D. Coconut

Explanation: Anemophily is the pollination by wind. Anemophilous plants are characterized by small flowers, pollens present in large number which are…

• A. Diploid
• B. Polyploid
• C. Triploid
• D. Haploid

Explanation: The endosperm of gymnosperms is haploid. It is a pre­fertilisation tissue and is equivalent to female gametophyte, hence it is haploid in…