Tag: zoology

Questions Related to zoology

The Pulmonary trunk and systemic aorta of Foetus, connected by?

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

  1. Ligamentum arteriosum

  2. Ductus arteriosus

  3. Ductus arteriosum

  4. Chordae terdinae

Show answer
Correct Option: B
Explanation:

The ductus arteriosus acts as a shunt between the pulmonary artery and the aorta during fetal development. In the fetus, before returning to the body, the blood is oxygenated in the placenta. Amniotic fluid fills the lungs and can not therefore be used to oxygenate the blood. Rather, the arterioles in the lungs restrict the quantity of blood flow that can pass through.

Human placenta is

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

  1. Haemochorial

  2. Syndesmochorial

  3. Yolk sac

  4. Haemo-endothelial

Show answer
Correct Option: A
Explanation:
Placenta, an organ characteristic of true mammals during pregnancy, joining mother and offspring, providing endocrine secretion and selective exchange of soluble blood borne substances through apposition of uterine and trophoblastic vascularized parts. In humans, haemochorial placenta is found in which all maternal layers are lost, so that foetal tissue is in contact with maternal blood. It is also seen in rodents, and most primates
So, the correct answer is 'Haemochorial'

Mammalian placenta originates from

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

  1. Allantois and chorion

  2. Yolksac

  3. Allantois

  4. Amnion

Show answer
Correct Option: A
Explanation:

The placenta is formed from the chorion and allantois of the embryo and from the mother's endometrium. Its main function is to allow the exchange of substances between the fetus and the mother's body. 

Placenta in human beings is formed by

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

  1. Amnion

  2. Chorion

  3. Allantois

  4. Allantois, chorion and uterine wall

Show answer
Correct Option: D
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.

The _____ is connecting structure which helps in the transfer of substance to and from the foetal body.

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

  1. Placenta

  2. Ovary

  3. Uterus

  4. vagina

Show answer
Correct Option: A
Explanation:

The placenta is an organ that connects the developing fetus to the uterine wall to allow nutrient uptake, waste elimination and gas exchange.
Ovary produces egg or ovum. Uterus is where implantation takes places and embryo develops. Vagina is the fibromuscular organ that facilitates sexual intercourse and childbirth.
Therefore, the correct answer is option A.

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

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

  1. Nourished through placenta

  2. Too small and need no much food

  3. MiIkfed

  4. None of the above.

Show answer
Correct Option: A
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. 

The placenta functions as

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

  1. A protective barrier between mother and embryo

  2. Supply oxygen and nutrients for growth of embryo

  3. Expel the waste matter excreted by the embryo

  4. All of the above

Show answer
Correct Option: D
Explanation:

The placenta is the region which is the main connection between mother and child. It connects the umbilical cord of the developing foetus to the mother's uterine wall to perform several functions. It acts as a barrier between the mother and embryo. It helps in the nutrient uptake, waste elimination, thermoregulation and gas exchange in the foetus through the mother's blood supply. 

Thus, the correct answer is option D. 

Placenta is the region, where

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

  1. Foetus is supplied by maternal blood

  2. Embryo is attached to mother by notocord

  3. Foetus receives maternal blood and nutrition

  4. Embryo is enclosed by membranes

Show answer
Correct Option: C
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. In most pregnancies, the placenta attaches to the top or side of the uterus. 

Therefore, the correct answer is option C.

Which substance normally passes from a fetus to its mother through the placenta?

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

  1. Alcohol

  2. Glucose

  3. Oxygen

  4. Urea

Show answer
Correct Option: D
Explanation:

The placenta is an organ responsible for providing oxygen and nutrients to the fetus from the mother, and removing waste substances like urea from the fetus to the mother.

Pick the mammal with true placenta.

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

  1. Kangaroo

  2. Echidna

  3. Platypus

  4. Mongoose

Show answer
Correct Option: D
Explanation:

The mammals that show the presence of a placenta is called placental mammals. They are also called eutherians. Mongoose is a placental mammal. The placenta is the connection between the developing fetus to the mother's uterine wall. The placenta performs several functions such as nutrient uptake, waste elimination and gaseous exchange in the fetus through the mother's blood supply. Thus the correct answer is option D.