Tag: biology

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Questions Related to biology

Multiple choice biology chemical coordination in plants abscisic acid fruit plants: structure and function

Abscisic acid controls

  1. Cell elogation and cell wall formation

  2. Shoot elogation

  3. Leaf fall and dormancy

  4. Cell division
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Abscissic acid regulates abscission (the shedding of leaves, flowers and fruits from the living plant) and dormancy. It acts as general plant growth inhibitor and also inhibit plant metabolism. It inhibits closure of stomata in epidermis, and increase tolerance of plant to various kinds of stresses, and therefore called as stress hormone.
ABA plays an important role in seed development, maturation and dormancy. By inducing dormancy, ABA helps seeds to withstand dessication and other factors favourable for growth.

Thus, the correct answer is option C.

Multiple choice biology chemical coordination in plants abscisic acid fruit plants: structure and function

State whether the following statements are true or false.
Dormancy of winter buds in temperate trees is caused by abscisic acid.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Abscisic acid is the hormones also called as stress hormones as they function in stress conditions. They are also known as dormant as they induce dormancy in buds. It mostly induced bud dormancy at the start of the winter season. They are generally growth hormone which inhibits growth normally.

So, the correct statement is 'True'.

Multiple choice biology chemical coordination in plants abscisic acid fruit plants: structure and function

State whether the following statements are true or false.
Dormancy of plants occurs in relation to abscisic acid.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Dormancy is the period when the physiological activities of the plant slow down for some time. Abscisic acid is a stress hormone that is responsible for the protection of plants in drought conditions. They are generally growth inhibitors and are also called as dormants. They are mainly responsible for the bud dormancy at the time of winter season and also cause seed dormancy and protect it from desiccation.

So, the correct statement is 'True'.

Multiple choice biology chemical coordination in plants abscisic acid fruit plants: structure and function

Choose the correct answer from the alternatives given.
Which of the following plant hormones is associated with the closure of the stomata in a plant under water stress?

  1. Abscisic acid

  2. Auxin

  3. Cytokinin

  4. Ethylene
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Abscisic acid inhibits seed germination and stimulates the closure of stomata in the epidermis and increases the tolerance of plants to various kinds of stresses. Therefore, it is also called the stress hormone.

So, the correct option is 'Abscisic acid'. 

Multiple choice biology chemical coordination in plants abscisic acid fruit plants: structure and function

Leaf abscission is caused by

  1. ABA

  2. cytokinin

  3. auxin

  4. gibberellin
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A plant will abscise apart either to discard a membrane that is no longer necessary, such as a leaf during autumn or a flower following fertilization or for the purpose of reproduction. Most deciduous plants drop their leaves by abscission before winter, whereas evergreen plants continuously abscise their leaves.

So, the correct option is 'ABA'.

Multiple choice gymnosperms pictorial feature of plant kingdom biology

Read the following five statements (A - E) and answer as asked next to them.
(A) In Equisetum the female gametophyte is retained on the parent sporophyte
(B) In Ginkgo male gametophyte is not independent
(C) The sporophyte in Riccia is more developed than that in Polytrichum
(D) Sexual reproduction in Volvox is isogamous
(E) The spores of slime molds lack cell walls
How many of the above statements are correct ?

  1. Three

  2. Four

  3. One

  4. Two
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
The spore of Equisetum germinate shortly after shedding and gives rise to form prothallus. Prothalli of Equisetum are basically monoecious and the gametophytes are rarely seen. The simplest known sporophyte among bryophytes is that of Riccia while highest evolved known is Bryopsida (Polytrichum, Pdgonatum). Sexual reproduction in Volvox is oogamous type. The spores in slime molds (e.g., Physarum) are haploid, unicellular, usually globose with smooth, spiny or reticulately thickened cell walls.

So, the correct answer is 'One'.
Multiple choice gymnosperms pictorial feature of plant kingdom biology

Which well-known tree is known in Britain as Wellingtonia?

  1. Elm

  2. Oak

  3. Giant sequoia

  4. Poplar
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Sequoiadendron giganteum is the sole living species in the genus Sequoiadendron. Giant sequoia specimens are the most massive trees on Earth.The name "Wellingtonia" has persisted in England as a common name, also known as giant redwood, sierra redwood, sierran redwood, Wellingtonia  or simply big tree.

So, the correct option is C. ( giant sequoia )

Multiple choice gymnosperms pictorial feature of plant kingdom biology

Gymnosperm with mycorrhiza is present in

  1. Cycas

  2. Casuarina

  3. Pinus

  4. Cedrus
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Roots in some genera of gymnosperms have fungal associations in form of mycorrhiza which is associated with N$ _2$ fixing cyanobacteria. For example, pinus.

So, the correct answer is 'Pinus'.

Multiple choice gymnosperms pictorial feature of plant kingdom biology

Both conifers and Cycas have?

  1. Motile sperms

  2. Non-motile sperms

  3. Motile & non-motile sperms respectively

  4. Non motile & motile sperms respectively
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

  • Conifers have non-motile sperm that needs to be moved along the pollen tube.
  • Cycads have motile sperm with flagella (they have multiple flagella) that help them move to the egg along the pollen tube.
So, the correct option is 'Non-motile & motile sperms respectively'.