Tag: botany

Questions Related to botany

In oogamous reproduction,

botany modes of reproduction fertilization in organisms sexual reproduction in organisms reproduction in organisms

  1. Both male and female gametes are motile

  2. Both gametes are product of division of protoplast

  3. Both male and female gametes are non-motile

  4. For male gametes protoplast divides but for female gamete it does not

Show answer
Correct Option: D
Explanation:

  • Oogamy is a system of sexual reproduction in which one gamete (called the egg) is large and nonmotile, while the other (called the sperm) is small and motile. Oogamy is a type of Anisogamy.
  • During Spermatogenesis, the protoplast of spermatogonium is equally divided into 4 spermatids while during oogenesis, ovum retains the bulk of protoplast and is minimally shared by Polar bodies.
So, the correct option is 'For male gametes protoplast divides but for female gamete it does not'.

Select the wrong statement :

botany modes of reproduction fertilization in organisms sexual reproduction in organisms reproduction in organisms

  1. Chlamydomonas exhibits both isogamy and anisogamy and Fucus shows oogamy.

  2. Isogametes are similar in structure, function and behaviour.

  3. Anisogametes differ either in structure, function or behaciour.

  4. In oomycetes, female gamete is smaller and motile while male gamete is larger and non-motile.

Show answer
Correct Option: B

Choose the correct answers from the alternatives given.
The principal embryonic membranes are

botany modes of reproduction fertilization in organisms sexual reproduction in organisms reproduction in organisms

  1. Chorion and umbilicus

  2. Amnion and placenta

  3. Amnion and chorion

  4. Placenta and umbilicus

Show answer
Correct Option: C
Explanation:
The placenta is an ephemeral organ found only in eutherian mammals during gestation. Placenta is the only organ composed of cells derived from two different organisms i.e. from the fetus and the mother. The fetal membranes are chorion and amnion. The membranes from the uterine wall are deciduas basalis. It is the portion of the deciduas which is directly adjacent to conception at the implantation site. Decidua is a mucous membrane lining the uterus during pregnancy and it cast off during childbirth. After the implantation of the embryo, the uterine endometrium is called decidua. Thus the principal embryonic membranes are Amnion and chorion.
So the correct option is ' Amnion and chorion '.

Rema was in the biology lab. When observing a plant tissue under the microscope, she saw a small out-growth coming from the outermost layer. Which part did she identify?

botany root - external morphology morphology of the root root system in plants root

  1. Trichomes

  2. Flower buds

  3. Stomata

  4. Leaves

Show answer
Correct Option: A
Explanation:

Rema observed trichomes which are considered to be the outgrowth from the epidermis of the plant and are unicellular and mostly glandular. It helps in the absorption of water and minerals.

So, the correct answer is 'Trichomes'.

A root grows in length,which region of the root is responsible for this growth?

botany root - external morphology morphology of the root root system in plants root

  1. Root cap

  2. Region of meristematic activity

  3. Region of elongation

  4. Region of maturation

Show answer
Correct Option: C
Explanation:

A)The root is covered at the apex by a thimble-like structure called the root cap that protects it from damage.

B)The cells are thin-walled and with dense protoplasm and divide rapidly forms region of meristematic activity.
C)The cells that divide undergo rapid elongation and are responsible for the growth of the root length is the region of elongation.
D)The cells of elongation gradually differentiate and mature is called the region of maturation.
So the correct option is ' Region of elongation'.

Roots and shoots lengthen through the activity of

botany root - external morphology morphology of the root root system in plants root

  1. Apical meristem

  2. Vascular Cambium

  3. Lateral meristem

  4. Cork Cambium

Show answer
Correct Option: A
Explanation:
Apical meristem is found at the growing tips, that is root and shoot tips. These are actively dividing cells and are thus responsible for the growth of plant lengthwise. Shoot apical meristem occurs at the apex of the shoot which allows the shoot to elongate. Root apical meristem occurs at the apex of the root which allows the root to elongate. Rapid division of meristematic cells can cause the plant to grow tall.
Thus, the correct answer is option A.

Quiescent centre is a

botany root - external morphology morphology of the root root system in plants root

  1. Weak zone

  2. Active zone

  3. Inactive zone

  4. Strong base

Show answer
Correct Option: C
Explanation:

Quiscent centre is a zone of mitotically inactive zone in the meristematic region of the root apical meristem. The cells of this region either do not divide or divide very slowly. They have thin cytoplasm, low concentration of the RNA and proteins, fewer endoplasmic reticulum and dictyosomes. This zone acts as reservoir of meristematic cells. The cells ar ecapable of gaining the active dision activity at the time of growth.

Hence, the correct answer is 'Inactive zone'.

Which of the following is absent in a root hair?

botany root - external morphology morphology of the root root system in plants root

  1. Cell wall

  2. Vacuole

  3. Nucleus

  4. Chloroplast

Show answer
Correct Option: D
Explanation:

Chloroplast are absent in root hairs because root hairs do not produce food. These are meant for absorption of water and minerals from soil. Chloroplast is the store house of chlorophyll which is the green pigment essential in photosynthesis.Moreover root and root hair are underground structures away from light, hence they do not contain chloroplasts, as chlorophyll pigments present within the chloroplasts are functional only in presence of light.

So, the correct answer is 'chloroplast'

Which of the following roots are found in a screwpine?

botany root - external morphology morphology of the root root system in plants root

  1. Nodulose

  2. Tuberous

  3. Stilt

  4. Fasciculated

Show answer
Correct Option: C
Explanation:

Screwpine or Pandanus also known as screw palm has stilt roots. Often called as Pandanus palms, these plants are not closely related to palm trees. The species vary in size from small shrubs less than 1 m. Species growing on exposed coastal headlands and along beaches have thick stilt roots- as anchors in the loose sand. Those prop roots emerge from the stem, usually close to but above the ground, which helps to keep the plants upright and secure them to the ground.
Thus, the correct answer is option C.

Transition of exarch bundles of root to endarch bundles of stem occurs in

botany root - external morphology morphology of the root root system in plants root

  1. Epicotyl

  2. Hypocotyl

  3. Apical bud

  4. Coleoptile

Show answer
Correct Option: B
Explanation:
Hypocotyl is the portion of seedling where transition of root structure into stem structure occurs. The seedling above the transition point has stem structure which is characterized by presence of collateral and endarch vascular bundles. And the region of hypocotyls below the transition point is structurally root, which bear radial and exarch vascular bundles. The transition point marks this conversion from exarch to endarch vascular bundles which makes option B correct. Epicotyl is the region of embryonic axis above the cotyledons which develops into leaves and is present above the hypocotyl; option A is incorrect. The protective covering that covers the epicotyls of monocot embryo is called as coleoptiles; they serve the protective function only; option D is incorrect. Apical bud is the meristematic tissue present in the tip of the stem and shoots which synthesize auxin and inhibits the lateral buds which are located in the base of the shoots; they are not involved in transition of root anatomy into stem anatomy; option C is incorrect.
Thus, the correct answer is option B.