Tag: growth and development in plants

Questions Related to growth and development in plants

Ebracteate flowers mainly found in

biology the flower structure of a bisexual flower growth and development in plants basics of leaf and flower

  1. Solanaceae

  2. Malvaceae

  3. Cruciferae

  4. Liliaceae

Show answer
Correct Option: C
Explanation:

Cruciferae flowers - The structure of the flowers is extremely uniform throughout the family. They have four free saccate sepals and four clawed free petals, staggered. They can be dissymmetric or slightly zygomorphic, with a typical cross-like arrangement (hence the name Cruciferae). 


They have six stamens, four of which are longer and are arranged in a cross-like the petals and the other two are shorter (tetradynamous flower). The pistil is made up of two fused carpels and the style is very short, with two lobes. Superior ovary. The flowers form ebracteate racemose inflorescences, often apically corymb-like. Flowers that do not have bracts at the base of pedicel (stalk of flower) are called as ebracteate flowers. Flowers of Solanaceae, Malvaceae and Liliaceae are bracteate flowers.
Therefore, the correct answer is option C.

Claw is found in the petals of

biology the flower structure of a bisexual flower growth and development in plants basics of leaf and flower

  1. Cruciferae

  2. Fabaceae

  3. Liliaceae

  4. Solanaceae

Show answer
Correct Option: A
Explanation:

The mustard family (Brassicaceae) consists mainly of annual to perennial herbs with watery acrid juices. They bear alternate leaves which lack stipules. The stems are often hairy, with forked or star-shaped (stellate) hairs. The calyx consists of 4 separate sepals and the corolla of 4 petals that are often separable into a narrow claw at the base, expanded into a broader limb at the upper petal end. The androecium is composed of 6 stamens in a unique tetradidynamous arrangement in which there are 4 long stamens and 2 short ones. The gynoecium is syncarpous (of 2 united carpels) containing ovules that are borne along the ovary wall. (This is called parietal placentation.) The ovary is divided internally, but because the partition goes across the carpels instead of between them, its regarded as a false partition (called as a replum) and the fruit is such a strikingly modified capsule that it has a special name, the silique or a silicle if short and squat. Claw is absent in petals of Fabaceae, Solanaceae and Liliaceae. 
Therefore, the correct answer is option A.

A nectar-secreting gland cell characteristically contains

biology the flower structure of a bisexual flower growth and development in plants basics of leaf and flower

  1. Granular cytoplasm filling the cell and a small nucleus.

  2. Granular cytoplasm living a central vacuole and a small nucleus.

  3. Granular cytoplasm filling the cell and a large conspicuous nucleus.

  4. Vacuolated cytoplasm but with a large nucleus.

Show answer
Correct Option: C
Explanation:

Nectaries are the excretory glands (that exude their secretion and do not store it) which are characterized by presence of rich granular cytoplasm in protoplast and conspicuous nucleus.
They lack vacuoles which makes. Large vacuole with inconspicuous cytoplasm and small nucleus are characteristic features of secretory cells that store their secretions. 
Therefore, the correct answer is option C.

Glumes are modified

biology the flower structure of a bisexual flower growth and development in plants basics of leaf and flower

  1. Petals

  2. Bracts

  3. Gynoecium

  4. Androecium

Show answer
Correct Option: B
Explanation:

Bracts are specialized leaves present in axis of flower. Small, dry, scaly bracts are called as glumes. For example, wheat and grass.
Thus, the correct answer is option B.

The perianth is the term used when

biology the flower structure of a bisexual flower growth and development in plants basics of leaf and flower

  1. Androecium and gynoecium are similar.

  2. Androecium and calyx are similar.

  3. Corolla and gynoecium are similar.

  4. Calyx and corolla are similar.

Show answer
Correct Option: D
Explanation:

Perianth is a collective term for outer parts of calyx and corolla enclosing androecium and gynoecium. This term is used to refer petalideous monocotyledons, in which the calyx and corolla are combined that they can be distinguished from each other.
Thus, the correct answer is option D.

Which of the following is regarded as equivalent to perianth?

biology the flower structure of a bisexual flower growth and development in plants basics of leaf and flower

  1. Glume

  2. Lodicule

  3. Superior palca

  4. Inferior palca

Show answer
Correct Option: B
Explanation:

A lodicule is one of two or three small scales at the base of the ovary in a grass flower that represent the corolla, believed to be a rudimentary perianth. For example, wheat (Triticum aestivum).

Thus, the correct answer is option B.

An inflorescence in which flowers arise from different points but reach the same level is called as

biology the flower structure of a bisexual flower growth and development in plants basics of leaf and flower

  1. Catkin

  2. Corymb

  3. Umbel

  4. Spadix

Show answer
Correct Option: B
Explanation:

Corymb : It is a slightly modified raceme in which the peduncle is relatively short while the pedicels of lower flowers are longer so that both young and old flowers are brought to more or less the same level, e.g., Cassz.a sophora.

Assertion : Gibberellins induce flowering in long day plants.

Reason : Genetically tall plant become dwarf by application of Gibberellin.

biology the flower structure of a bisexual flower growth and development in plants basics of leaf and flower

  1. If both the assertion and reason are true and the reason is a correct explanation of the assertion

  2. If both the assertion and reason are true but the reason is not a correct explanation of the assertion

  3. If the assertion is true but the reaon is false

  4. If both the assertion and reason are false

  5. If the assertion is false but reason is true

Show answer
Correct Option: C
Explanation:

Application of GA can induce flowering in long day plants. It has no favourable effect on size of flower and fruit in certain plants. The genetically dwarf plants can be made tall by application of GA.

From among the situations given, choose the one that prevents both autogamy and geitonogamy.

biology the flower structure of a bisexual flower growth and development in plants basics of leaf and flower

  1. Monoecious plant bearing unisexual flowers

  2. Dioecious plant bearing only male or female flowers

  3. Monoecious plant with bisexual flowers

  4. Dioecious plant with bisexual flowers

Show answer
Correct Option: B
Explanation:

Monoecious(bisexual)plant bearing either bisexual or unisexual flowers can exhibit both autogamy as well as geitonogamy. Dioecious(unisexual) plants bearing only male or female flowers will not show autogamy or geitonogamy and only xenogamy is possible.

Read the following four statements (A-D).


(A) Flowers are the morphological and embryological marvel and the site of sexual reproduction.
(B) Anther are attached to the proximal end of the filament of stamen.
(C) Androecium and gynoecium represent the non-essential part of the flower.

(D) The number and length of stamens are variable in flower of different species. 

How many statements are correct? 

biology the flower structure of a bisexual flower growth and development in plants basics of leaf and flower

  1. One

  2. Two

  3. Three

  4. Four

Show answer
Correct Option: B
Explanation:

  • A flower is a reproductive structure of a flowering plant, which is a morphological and embryological marvel and the site of sexual reproduction.
  • Anther is attached to the distal end of the filament of the stamen.
  • Androecium (stamens) and gynoecium (pistils) represent essential parts of a flower.
  • The number and length of stamens are variable in flowers of different species.
So, the correct statements are 'Two'.