Biology

Embryonic Development

572 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 zoology reproduction in humans placenta pregnancy and birth fertilization and post fertilization in humans

Placenta in human beings is formed by

  1. Amnion

  2. Chorion

  3. Allantois

  4. Allantois, chorion and uterine wall
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The placenta is an organ, that connects the developing foetus to the uterine wall to allow nutrient uptake, waste elimination, and gas exchange via the mother's blood supply, fight against internal infection and produce hormones to support pregnancy. In humans, the placenta usually has a disc shape and it is formed by allantois, chorion and uterine wall.

Multiple choice zoology reproduction in humans placenta pregnancy and birth fertilization and post fertilization in humans

Mammalian egg contains negligible yolk so the survival of such embryo is made possible by the fact that they are

  1. Nourished through placenta

  2. Too small and need no much food

  3. MiIkfed

  4. None of the above.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
All mammals except the monotremes are viviparous. In viviparous animals (such as humans ) the eggs have hardly any food reserve. In these animals, embryo receives nutrients from the mother through a special structure called placenta and remains enclosed in the womb (uterus) until birth. This kind of situation is found in higher mammals (eutherians) and some fishes (sharks). In contrast, eggs of oviparous and ovoviviparous animals contain yolk which is utilized by the developing embryo. The yolk contains all the required nutrients. This kind of situation is found in fishes, amphibians, reptiles, birds and primitive mammals. 
Multiple choice zoology reproduction in humans placenta pregnancy and birth fertilization and post fertilization in humans

Which one of the following develops from the trophoblast?

  1. Placenta

  2. Allantois

  3. Epidermis of the skin

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

Trophoblasts are the cells forming the outer layer of a blastocyst, which provides nutrients to the developing embryo and it develops into a large part of placenta. Thus, trophoblasts are specialized cells of the placenta that plays an important role in embryo implantation.
Thus, the correct answer is option (A), 'Placenta'.

Multiple choice zoology reproduction in humans placenta pregnancy and birth fertilization and post fertilization in humans

Attachment of foetus of placenta occurs through

  1. Chorda mesoderm

  2. Spinal cord

  3. Umbilical cord

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

In humans, the placenta is chorionic in nature. It attaches the foetus and the mother and is responsible for the nutrition and excretion and exchange of gases.

The umbilical cord is a tube-like structure that connects the foetus and mothers placenta. The belly button is the entry point of the umbilical cord in the foetus. The umbilical cord contains arteries and veins and is protected by a jelly-like substance known as the Wharton's jelly.
So, the correct option is 'Umbilical cord' 

Multiple choice zoology reproduction in humans placenta pregnancy and birth fertilization and post fertilization in humans

Extra structure which provides nutrition to embryo is

  1. Umbilicus

  2. Chorion

  3. Placenta

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

After implantation, finger-like projections appear on the trophoblast called chorionic Villi which are surrounded by uterine tissue and maternal blood. The chronic villi and uterine tissue become interdigitated with each other and jointly form a structural and functional unit between developing embryo that is foetus and maternal body called placenta. Placenta facilitate the supply of oxygen and nutrients to the embryo and also helps in removal of carbon dioxide in excretory waste materials produced by the embryo.

 So, the correct option is 'Placenta'.

Multiple choice zoology reproduction in humans placenta pregnancy and birth fertilization and post fertilization in humans

What is formed by chorionic villi cooperating with the tissues of uterus of mother?

  1. Placenta

  2. Embryonic disc

  3. Umbilical cord

  4. Embryonic layer
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
The chorion, which means as the membrane covering the fetus is the outermost extraembryonic membrane. The two types of cells namely cytotrophoblast cells and syncytiotrophoblast cells form chorion. These cells combine with the functional layer of the endometrium and form the placenta, which is the site of gas and nutrient exchange between the embryo and the mother. Hence, the correct answer is option A, Placenta.

Multiple choice zoology reproduction in humans placenta pregnancy and birth fertilization and post fertilization in humans

The most primitive type of mammalian placenta is

  1. Syndesmochorial

  2. Endotheliochorial

  3. Haemochorial

  4. Epithelicohorial
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Epitheliocohorial type of mammalian placenta is observed in cattle, pigs etc
wherein the chorion is superficially aligned on the endometrium and does not penetrate it.
So, the correct answer is 'Epithelicohorial'

Multiple choice zoology reproduction in humans placenta pregnancy and birth fertilization and post fertilization in humans

Which of the following structures serves as a lung, digestive tract, and kidney for the developing embryo?

  1. Placenta

  2. Endometrium

  3. Amnion

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

The placenta is an organ that develops in the uterus during pregnancy. This structure provides oxygen and nutrients to the growing baby and removes waste products from the baby's blood. The placenta attaches to the wall of the uterus, and the baby's umbilical cord arises from it. The organ is usually attached to the top, side, front or back of the uterus.

So the correct option is 'placenta'.

Multiple choice zoology frog introduction to reproduction reproductive system in frog frog - digestive system, circulatory system, excretory system and reproductive system

The development of frog is

  1. Direct

  2. Indirect

  3. Parthenogenetic

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

In indirect development, an animal's birth form is different from the adult form. The embryo hatches from the egg in the larval form. The larva undergoes a drastic metamorphosis in order to achieve its adult stage. Frog, the adult form is completely different from the tadpole, its birth form. Hence, frog undergoes indirect development.
So, the correct answer is option B.

Multiple choice zoology frog introduction to reproduction reproductive system in frog frog - digestive system, circulatory system, excretory system and reproductive system

Egg of frog is

  1. Microlecithal and homolecithal

  2. Polylecithal and centrolecithal

  3. Moderately telolecithal and mesolecithal

  4. Heavily telolecithal and polylecithal
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The egg of the frog is mesolecithal as moderate amount of yolk is present. As the yolk is concentrated in the lower part of the egg and the cytoplasm in the upper part, these eggs are moderately telolecithal. 

So, the correct answer is 'Moderately telolecithal and mesolecithal'.

Multiple choice zoology frog introduction to reproduction reproductive system in frog frog - digestive system, circulatory system, excretory system and reproductive system

Albuminous layer around the egg of Frog is deposited by

  1. Ovarian follicles

  2. Ovary

  3. Oviduct

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

The frog egg is surrounded by an albuminous layer by an oviduct which later it comes into a uterus. The oviduct is a long coiled duct with the thick wall that is not connected with kidneys.  It consists some glands which secrete albumen that hardens ova. After the ovulation, the cilia of the oviducal funnel draws the coelomic fluid with ova which moves into the middle region with the help of cilia.

So the correct answer is 'Oviduct'.

Multiple choice sexual reproduction in flowering plants reproduction - the generating system reproduction sexual reproduction biology reproductive health of humans need of family planning reproductive health problems cell division in embryo development division for growth and reproduction reproductive health

Study of formation, growth and development of new individual from an egg is?

  1. Apomixis

  2. Embryology

  3. Embryogeny

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

Embryology is the branch of biology that studies the formation, growth, and development of an embryo from an egg (zygote).

Multiple choice sexual reproduction in flowering plants reproduction - the generating system reproduction sexual reproduction biology reproductive health of humans need of family planning reproductive health problems cell division in embryo development division for growth and reproduction reproductive health

Ovule is curved and the embryo sac is horseshoe shaped. Micropyle, chalaza and funicle occur near one another. The ovule is?

  1. Campylotropous

  2. Amphitropous

  3. Orthotropous

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

In an amphitropous ovule, the embryo sac is curved into a horseshoe shape, and the micropyle, chalaza, and funicle are brought close together.

Multiple choice biology anatomy of flowering plants theories of meristematic cell development theories of shoot apical meristem development shoot and root apex

Root cap of the embryo develops from:

  1. Basal cell

  2. Apical cell

  3. Hypophysis

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

 The formation of the root apex involves derivatives of both the basal and apical cells of the two-cell embryo, the hypophyseal region derived from the topmost cell of the suspensor is incorporated into the embryo proper, giving rise to part of the root cap.

So, the correct option is 'Hypophysis'.

Multiple choice botany plant tissues - internal morphology and anatomy theories of meristematic cell development theories of shoot apical meristem development shoot and root apex

Histogen is a

  1. Promeristem derivative destined to produce specific areas

  2. Intercalary meristem meant for forming specific tissue

  3. Derivative of lateral meristem

  4. Secondary meristem specialised to produce specific structures
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • Promeristem is a group of young meristematic cells in its early embryonic stage from which other meristems are derived. 
  • Apical meristems are derived from promeristem and are present below the promeristem at shoot tip and root tip.
  • The shoot apical meristem (SAM) consists of three distinct meristematic zones called the histogens.
  • These histogens are present at the growing tips of a stem or a root.
  • These tips consist of three histogens and each of these histogens gives rise to tissues which are different from one another- dermatogen, periblem, plerome (principle tissues)
  • The dermatogen or the outer layer gives rise to the epidermis, periblem or middle layer gives rise to the cortex as well as the epidermis, plerome or the inner layer gives rise to vascular tissues.
  • So, the correct answer is 'Promeristem derivative destined to produce specific areas'.