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 plant growth seed dormancy fruit plants: structure and function

Embryo are not differentiated into different tissues at the time of fruit ripening. Select option related to this statement?

  1. Endogenous dormancy, morphological dormancy

  2. Exogenous dormancy, physiological dormancy

  3. Exogenous dormancy, morphological dormancy

  4. Endogenous dormancy, mechanical dormancy
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
The dormancy caused by conditions within the embryo itself is called endogenous dormancy. It includes physiological dormancy, morphological dormancy, and combined dormancy, Morphological dormancy is a type of endogenous dormancy. In this, the embryo is underdeveloped or undifferentiated. Thus, the correct option is A.
Multiple choice zoology the endocrine system adrenal gland thymus and adrenal gland adrenal glands

Adrenal gland is derived from

  1. Endoderm

  2. Ectoderm

  3. Mesoderm

  4. Ectoderm and mesoderm
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
During embryonic stages, three germ layers are formed which give rise to various organs of foetus. The three germ layers are:
  • Outer layer ectoderm
  • Middle layer mesoderm
  • Inner layer endoderm
Adrenal gland has two parts, adrenal cortex and adrenal medulla.
Adrenal cortex is derived from mesoderm and adrenal medulla is derived from ectoderm.
So, the correct answer is 'Ectoderm and mesoderm'.
Multiple choice biology the flower importance of pollination flower: parts of a flower flower and pollination

Testa of seed develops from

  1. Ovary wall

  2. Hilum

  3. Outer integument

  4. Funicle
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
A. Ovary becomes a fruit.
B. The hilum marks the point of attachment to the stalk.
C. Outer integument becomes hard and leathery testa or outer seed coat which ensures survival of seeds.
D. Funicle is transformed into stalk of the seed.
So, the correct answer is 'Outer integument'.
Multiple choice biology the flower importance of pollination flower: parts of a flower flower and pollination

Tegmen develops from

  1. Funiculus

  2. Chalaza

  3. Inner integument

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

A. Funiculus- It is the stalk like structure which attaches the ovule to the placenta.

B. Chalaza- It is the place of origin of the integuments or the basal swollen part of the nucellus.
C. The inner integuments, if persists, forms the tegmen.
D. The outer integument becomes hard and leathery testa or outer seed coat which ensures survival of seeds.
So, the correct answer is 'Inner Integument'.

Multiple choice botany pollination, fertilization and development of endosperm and embryo fruits and seeds fruit and its type fertilization events

Aleurone layer takes part in

  1. Protein of delicate embryo

  2. Enzyme synthesis

  3. Transfer of food to cotyledons

  4. Transfer of food from cotyledons to embryo tips
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In monocotyledonous endospermic seed, endosperm is surrounded by a special one- cell thick layer, called aleurone layer. Its main function is to nourish the embryo enclosed in the seed.It is protein rich coat formed by the outermost layer of endospermic cells. It actively secretes few enzymes which help in the process of seed germination.
So, the correct answer is 'Enzyme Synthesis'.

Multiple choice zoology control and coordination in living organisms thymus thymus gland pineal gland and thymus

Thymus gland develops from embryonic 

  1. Mesoderm

  2. Endoderm

  3. Ectoderm

  4. All of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The triploblastic animals have three prominent germ layers known as ectoderm, endoderm and mesoderm. Thymus gland develops from two hollow elongations (third and fourth pharyngeal pouches) of endoderm which descends to the embryonic thorax by the end of eight weeks of gestation. The lymphoid cells of the gland originate from mesoderm. Thus, the correct answer is option B.

Multiple choice biology the life cycle of animals types of reproduction in animals oviparous and viviparous a study on animals

In mammals egg are microlecithal and isolecithal because these are

  1. Oviparous

  2. Viviparous

  3. Ovoviviparous

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Mammalian eggs have very little yolk (microlecithal) because the embryo obtains maternal nutritional support throughout its development.

Isolecithal  refers to the even distribution of yolk in the cytoplasm of the ovum in mammals and other vertebrates. In mammals, because the isolecithal cells have only a small amount of yolk, they require immediate implantation onto the uterine wall to receive nutrients.
So, the correct answer is option B.

Multiple choice biology the life cycle of animals types of reproduction in animals oviparous and viviparous a study on animals

The development of embryo inside an egg is called as

  1. Vivipary

  2. Carnivorous

  3. Omnivorous

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

Vivipary is the development of the embryo inside the body of the mother, eventually leading to live birth.
Carnivorous are animals that feed on animal tissues.
Omnivorous are animals that feed on plant and animals.
Ovipary is the method of reproduction in which eggs are laid and embryos develop outside the mother's body, each egg eventually hatching into a young animal.
So, the correct answer is option D.

Multiple choice biology the life cycle of animals types of reproduction in animals oviparous and viviparous a study on animals

The animals in which complete embryo develops in the mother's body through placenta are 

  1. Oviparous

  2. Viviparous

  3. Ovo-viviparous

  4. Herbivorous
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

  • Oviparous animals are the animals that lay eggs.
  • Viviparous animals give birth to the living offspring that develop within the mother's body (as in the case of most of the mammals).
  • Ovo-viviparous give birth to the young ones in eggs which are hatched within the female body (as in some reptiles and fishes).
  • Herbivorous animals are those that feed exclusively on vegetable food.
So, the correct answer is option B.

Multiple choice biology the life cycle of animals types of reproduction in animals oviparous and viviparous a study on animals

Egg with peripheral cytoplasm around the yolk is

  1. Isolecithal

  2. Microlecithal

  3. Telolecithal

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

Centrolecithal eggs have yolk concentrated in the center as in insects. 

Telolecithal eggs have yolk concentrated at one end. 
Isolecithal eggs have yolk evenly distributed in the cytoplasm. 
Microlecithal eggs have a very little yolk.
So, the correct answer is option D.

Multiple choice biology the life cycle of animals types of reproduction in animals oviparous and viviparous a study on animals

The process by way of which a larva or miniature adult comes out of the egg membranes is known as

  1. Hatching

  2. Emboly

  3. Epiboly

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

Larva comes out from the egg membranes is called as Hatching. Formation of a gastrula from a blastula by invagination is called as Emboly. cell movements that occur in the Gastrulation stage of embryonic development of some organisms are called as Epiboly and changes in the location or relative position of cells that takes place during the gastrulation stage of animal development is called as Ingression.

So the correct option is 'Hatching.'

Multiple choice botany modes of reproduction why do plants reproduce? reproduction and variation the life cycle of plants

The egg of frog is

  1. Microlecithal

  2. Mesolecithal

  3. Centrolecithal

  4. Alecithal
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Mesolecithal egg are those eggs that has a yolk of intermediate size and strongly concentrated in one hemisphere. The young hatch at a later stage of development. It is a characteristic of lung fishes and amphibians likes frog. Hence, option B is correct.