Tag: placenta

Questions Related to placenta

Extra structure which provides nutrition to embryo is

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

  1. Umbilicus

  2. Chorion

  3. Placenta

  4. Amnion

Show answer
Correct Option: C
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'.

Metadiscoidal placenta is found in

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

  1. Humans

  2. Cow

  3. Pig

  4. Rabbit

Show answer
Correct Option: A
Explanation:

The placenta in which the villi are restricted to a disk-shaped chorionic area on the ventral side of the embryo is known as the metadiscoidal placenta found in humans.

So the correct option is 'Humans'.

Which one is not a character of haemochorial placenta?

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

  1. $CO _2$ and excretory products pass from foetus to mother's body.

  2. $O _2$ and nutrients from mother's body enter the foetus.

  3. Chorion villi are covered by blood sinuses of mother.

  4. It protects foetus from mechanical shocks.

Show answer
Correct Option: D
Explanation:

The haemochorial placenta is the type of placenta in which maternal blood is in direct contact with the chorionic villi which are covered by maternal blood and exchange of gases and nutrients from mother's blood and foetus takes place as observed in humans.

So the correct option is 'It protects foetus from mechanical shocks'

Which is not correct about placenta?

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

  1. It prevents passage of maternal IgG to foetus.

  2. It acts as foetal lung.

  3. It acts as foetal liver.

  4. It acts as endocrine gland.

Show answer
Correct Option: A
Explanation:
The placenta is a cushion-like tissue which facilitates the supply of oxygen and nutrients to the embryo and also the removal of carbon dioxide and excretory waste materials produced by the embryo. It also acts as an endocrine tissue and produces several hormones such as human chorionic gonadotropin, human placental lactogen, estrogens, progesterone and relaxin during pregnancy.
So, the correct option is 'It prevents passage of maternal IgG to the foetus'.

Which of the following is not the function of placenta?

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

  1. Secretes oxytocin during parturition

  2. Facilitates supply of $O _2$ and nutrients to embryo

  3. Secretes estrogen

  4. Facilitates removal of $CO _2$ and waste products from embryo

Show answer
Correct Option: A
Explanation:
The placenta is a cushion-like tissue which facilitates the supply of oxygen and nutrients to an embryo and also the removal of carbon dioxide and excretory waste materials produced by the embryo. It also acts as an endocrine tissue and produces several hormones such as human chorionic gonadotropin, human placental lactogen, estrogens, progesterone and relaxin.
So, the correct option is 'Secretes oxytocin during parturition'.

What is placenta? 

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

  1. Special tissue connection between embryo and uterine wall

  2. Facilitate passage of nutrition and oxygen to embryo from mother through blood

  3. Waste substances produced by embryo are removed through placenta into mothers blood

  4. All of the above

Show answer
Correct Option: D
Explanation:

  • Placenta is a special organ or tissue that connects the developing fetus to the uterine wall. It allows nutrient uptake, waste elimination, gas exchange via the mother's blood supply, fight against internal infection and produces a hormone to support pregnancy.

Therefore, the correct answer is option D.

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

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

  1. Placenta

  2. Embryonic disc

  3. Umbilical cord

  4. Embryonic layer

Show answer
Correct Option: A
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.

The most primitive type of mammalian placenta is

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

  1. Syndesmochorial

  2. Endotheliochorial

  3. Haemochorial

  4. Epithelicohorial

Show answer
Correct Option: D
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'

Haemoendothelial placenta occurs in

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

  1. Man and Ape

  2. Cow and Goat

  3. Deer and Camel

  4. Rat and Rabbit

Show answer
Correct Option: D
Explanation:

In the hematoendothelial placenta, the outer covering which is the trophoblast becomes so thin that it appears that the maternal blood is separated from the fetal blood only by a single layer of cells of the embryonic layer chorion. This type of placenta is generally found in Rat and rabbit.


So, the correct option is ' Rat and Rabbit.'

Considering the following:
1) Endothellium of foetal blood capillaries 
2) Connective tissues surrounding foetal blood capillaries
3) Chorionic epithelium
4) Maternal epithelium 
5) Connective tissue surrounding maternal blood capillaries 
6) Endothelium of maternal blood capilaries 
In the case of humans, the placenta comprises which of the above?

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

  1. 1 , 2, 3, 4, 5 and 6

  2. 1, 2, 3 and 6

  3. 1, 2 and 3

  4. 1, 2, 3 and 5

Show answer
Correct Option: A
Explanation:

The human placenta has chorionic epithelial cells. It has maternal endothelial cells of blood capillaries, maternal endometrial epithelium and endothelium of foetal blood capillaries. The foetal connective tissue surrounds the foetal endothelial blood capillaries. The maternal connective tissue surrounds the maternal blood capillaries. 

Thus, the correct answer is '1, 2, 3, 4, 5 and 6'.