Biology

Embryonic Development

621 Questions

Embryonic development questions cover the biological processes of gamete fusion, germ layer formation, and fetal maturation. The focus lies in identifying extraembryonic structures, trophoblast functions, and sequential developmental stages. This specialized topic appears regularly in biology screening tests and medical entrance examinations.

Germ layer formationBlastocyst implantationExtraembryonic structuresFetal development stagesReproductive physiology

Embryonic Development Questions

Multiple choice biology reproduction in living organisms regeneration asexual modes of reproduction reproduction in animals

Formation of whole body from a fragment is

  1. Morphallaxis

  2. Epimorphosis

  3. Epigenesis

  4. Auxetic growth
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A. Morphallaxis - The reconstruction of an entire animal from a small fragment by reorganizing the existing cells, is called Morphallaxis.

B.Epimorphosis - The regeneration of tissues or organs through the dedifferentiation of existing, differentiated adult tissues

C.Epigenesis - The theory, now generally held, that an embryo develops progressively from an undifferentiated egg cell.

D. Auxetic growth – Growth takes place by the influence of auxins.

So, the correct option is ‘Auxetic growth’.

Multiple choice development of plants plant growth growth and development plant growth and development biology

If a mature differentiated cell develops into an embryo, the phenomenon

is ..........................

  1. Morphogenesis

  2. Maturation

  3. Differentiation

  4. Dedifferentiation
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The living differentiated cells that by now have lost the capacity to divide can regain the capacity of division under certain conditions. This phenomenon is termed as dedifferentiation. Example: formation of meristems - interfascicular cambium and cork cambium from fully differentiated parenchyma cells.

Multiple choice botany plant tissue system ground tissue system ground tissues tissue systems

Endodermis is part of

  1. Epidermal system

  2. Intrastelar tissue

  3. Extrastelar tissue

  4. Vascular tissue
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Secondary growth refers to addition of extra amount of tissue in the stelar and extrastelar region due to activity of lateral meristem i.e., vascular cambium (fascicular cambium) and cork cambium respectively. Secondary growth in extra stelar zone extends from hypodermis to endodermis and made up of primary tissues during primary growth. 
So, the correct answer is 'Extrastelar tissue.'
Multiple choice botany plant tissue system ground tissue system ground tissues tissue systems

Periblem gives rise to

  1. Epidermis

  2. Cortex

  3. Cortex and endodermis

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

In the histogen theory Henstein divided the shoot apex into various zones. Each zone consists of a group of initial cells and called as histogen or a tissue builder.

The major histogens of the stem and roots are -(a) the dermatogen, a meristematic external layer, (b) the plerome, a central core and (c) the periblem, the region between the two. 
The dermatogen gives rise to the epidermis, the prerome to the primary vascular bundles and the periblem develops into the cortex and endodermis.

Multiple choice botany plant tissue system ground tissue system ground tissues tissue systems

Periblem forms

  1. Endodermis

  2. Cortex

  3. Both A and B

  4. Epidermis
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  • The shoot apical meristem (SAM) of a plant form three distinct meristematic zones called the Histogens.
  • These histogens are present at the growing shoot tip or root tip.
  • These tips consist of three histogens based on the type of cells they form.
  • Each of these histogens gives rise to tissues which are different from one another- dermatogen, periblem, plerome (principle tissues)
1) The dermatogen or the outer layer gives rise to the epidermis.
2) The periblem or middle layer gives rise to the cortex and the endodermis (compact living cells with hydrophobic substances) which is the innermost layer of the cortex.
3)The plerome or the inner layer gives rise to vascular tissues.
So, the correct answer is 'Both A and B'.
Multiple choice botany plant tissue system ground tissue system ground tissues tissue systems

Endodermis is part of

  1. Medulla

  2. Stele

  3. Cortex

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

A. Medulla – central part of the stele.

B. Stele – central part of the root and dicot stem, includes pericycle, vascular bundles, medulla, medullary rays or conjuctive tissue.

C. Cortex – middle part of the dicot stem and root, includes hypodermis, general cortex and endodermis.

D. Exodermis – outer part of mature monocot root.

So, the correct option is ‘Cortex’.

Multiple choice biology multicellular structure: tissue defense mechanism in plants epidermal tissue system kinds of plant tissue permanent tissues and their types

Endodermis is a part of

  1. Vascular tissue system

  2. Extrastelar tissue system

  3. Epidermal tissue system

  4. Intrastelar tissue system
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The epidermal tissues system forms the outer protective covering of primary plant body in form of epidermis and of secondary plant organs in form of periderm. 

During secondary growth, rupturing of epidermal cell and outer cortex by secondary tissues induces formation of new protective layer, periderm which in turn divides to form cork cambium /phellogen. 
Vascular tissues system consists of stele, which is the central region having vascular bundle, pericycle, pith and medullary rays. 
The tissues present outside the stele forms extrasteler tissues system. Stele is surrounded by endodermis and cortex, these two together make extra steler system. 
Intrasteler tissues system refers to the tissues present in a stele i.e., vascular bundle, pericycle, pith and medullary rays.

Multiple choice biology multicellular structure: tissue defense mechanism in plants epidermal tissue system kinds of plant tissue permanent tissues and their types

Endodermis is a part of

  1. Cortex

  2. Pericycle

  3. Medulla

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

A conspicuous part of the primary structure of many roots is the endodermis, the innermost layer of the cortex, the walls of which often become conspicuously thickened, plus strips of suberized tissue on the radial walls called as 'Casparian strips.'

Multiple choice biology multicellular structure: tissue defense mechanism in plants epidermal tissue system kinds of plant tissue permanent tissues and their types

Periblem form

  1. Endodermis

  2. Cortex

  3. Both A and B

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

Histogen theory (By Hanstein 1870) concludes that shoot apical meristem consists three distinct zones. 

Dermatogen (external layer), which forms the outer covering of all organ of the plant. 
Periblem (middle layer) gives rise to the cortex and endodermis. 
Plerome (central layer) forms pith and primary vascular bundle. 
Thus, option C is correct.

Multiple choice botany asexual and sexual reproduction in plants structure of male and female reproductive structures structure of ovule gynoecium

The point of attachment of funicle with chalazal end is called as 

  1. Placenta

  2. Integument

  3. Nucellus

  4. Hilum
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The hilum is the point of attachment of funicle with the chalazal end. It is the point where ovule attaches to the base. It is generally present as an eye of the seed as it is present as a scar.

Multiple choice botany asexual and sexual reproduction in plants structure of male and female reproductive structures structure of ovule gynoecium

In ovule, endothelium is

  1. Nucellus

  2. Nucellus surrounding embryo sac

  3. Tissue near chalaza

  4. Inner part of integument
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
In some plants having unitegmic and tenuinucellate ovules, the nucellus degenerates at an early stage. In such ovules, the innermost layer of the integument becomes specialized to perform the nutritive function of the growing embryo sac. This specialized tissue is called the Endothelium. The endothelium is generally single layered and the cells are radially elongated and have dense cytoplasm. Hence, in the ovule Endothelium is the inner part of the integument.
So, the correct answer is D.
Multiple choice botany asexual and sexual reproduction in plants structure of male and female reproductive structures structure of ovule gynoecium

Starting from the Innermost part, the correct sequence of parts in an ovule are.

  1. Egg, nucellus, embryo sac, integument

  2. Egg, embryo sac, nucellus, integument

  3. Embryo sac, nucellus, integument, egg

  4. Egg, integument, embryo sac, nucellus
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Egg cell is inside the embryo sac in the ovule. The embryo sac is further enclosed by the parenchymatous tissue, nucellus, which provides nutrition to developing embryo. Nucellus is ultimately surrounded by integuments.

Multiple choice botany seeds - structure and germination what is a seed? seeds seed

Cotyledonary node of embryo lies between 

  1. Hypocotyl and radicle

  2. Epicotyl and plumule

  3. Epicotyl and hypocotyl

  4. Cotyledons and radicle
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Cotyledonary node of embryo lies between epicotyl and hypocotyl. The epicotyl is the embryonic shoot above the cotyledons. In most plants the epicotyl will eventually develop into the leaves of the plant. In dicots, the hypocotyl is what appears to be the base stem under the spent withered cotyledons and the shoot just above that is the epicotyl.
In monocot plants, the first shoot that emerges from the ground or from the seed is the epicotyl, from which the first shoots and leaves emerge.
Therefore, the correct answer is option C.