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Sexual Reproduction

Description: pregnancy and embryonic development
Number of Questions: 17
Created by:
Tags: zoology Sexual Reproduction Reproduction in Organisms
Attempted 0/17 Correct 0 Score 0

Which of the following hormones is secreted by placenta?

  1. Human chorionic gonadotropin

  2. Human placental lactogen

  3. Estrogen

  4. Progestogens

  5. All of the above


Correct Option: E
Explanation:

Placenta also acts as an endocrine tissue and produces several hormones like human chorionic gonadotropin (hCG), human placental lactogen (hPL), estrogens, progestogens, etc.

Which of the following hormones is produced only during pregnancy?

  1. Human chorionic gonadotropin

  2. Human placental lactogen

  3. Relaxin

  4. 1 and 2

  5. 1, 2, and 3


Correct Option: E
Explanation:

Human chorionic gonadotropin (hCG) and human placental lactogen (hPL) are secreted by placenta and relaxin is also secreted by the ovary during later phase of pregnancy.

In human beings the embryo’s heart is formed ___________.

  1. after one month of pregnancy

  2. by the end of second month of pregnancy

  3. by the end of 12 weeks

  4. by the end of 24 weeks

  5. by the end of nine months of pregnancy


Correct Option: A
Explanation:

In human beings after one month of pregnancy, the embryo’s heart is formed.

The baby's first stool is known as _________.

  1. beestings

  2. bisnings

  3. meconium

  4. colostrum

  5. forestool


Correct Option: C
Explanation:

The baby's first stool is known as meconium.

How many days after fertilization, the blastocyst attaches to the wall of the uterus?

  1. 2-3 days

  2. 5-7 days

  3. 8-10 days

  4. 10-12 days

  5. 13-15 days


Correct Option: B
Explanation:

5-7 days after fertilization, the blastocyst attaches to the wall of the uterus (endometrium). When it comes into contact with the endometrium it performs implantation.

At what point of time the embryonic stage is over and the fetal stage begins?

  1. at the end of 4th week

  2. at the end of 8th week

  3. at the end of 12th week

  4. at the end of 24th week

  5. none of the above


Correct Option: B
Explanation:

At the end of the 8th week, the embryonic stage is over, and the fetal stage begins. By the end of the second month of pregnancy, the foetus develops limbs and digits.

Which of the following antibodies is most abundantly present in human milk?

  1. IgA

  2. IgG

  3. IgM

  4. IgE

  5. IgD


Correct Option: A
Explanation:

Quantity of different antibodies found in human milk is in the order of IgA > IgG > IgM.

Which of the following syndromes is a type of monosomy?

  1. Down Syndrome

  2. Klinefelter syndrome

  3. Turner Syndrome

  4. Patau syndrome

  5. None of the above


Correct Option: C
Explanation:

An example of monosomy is Turner Syndrome where the individual is born with only one sex chromosome, an X.

Which of the following causes is the most common natural cause of abortion of an embryo?

  1. Advancing maternal age

  2. A patient history of previous spontaneous abortions

  3. Chromosomal abnormality

  4. Progesterone deficiency

  5. Uterine malformation


Correct Option: C
Explanation:

The most common natural cause of abortion of an embryo is chromosomal abnormality, which accounts for at least 50% of sampled early pregnancy losses.

The germ layers, i.e., ectoderm, mesoderm, and endoderm, in organogenesis differ by which of the following processes?

  1. Folds

  2. Splits

  3. Condensation

  4. 1, 2 and 3

  5. Shape and number of cells


Correct Option: D
Explanation:

The germ layers in organogenesis differ by three processes: folds, splits, and condensation.

Placenta connects to the fetus by an umbilical cord, which contains _________.

  1. one umbilical artery and one umbilical vein

  2. two umbilical arteries and one umbilical vein

  3. two umbilical arteries and two umbilical veins

  4. one umbilical artery and two umbilical veins

  5. three umbilical veins and one umbilical artery


Correct Option: B
Explanation:

Placenta connects to the fetus by an umbilical cord,  which contains two umbilical arteries and one umbilical vein.

Avascular type of allantois is seen in which of the following animals?

  1. Mouse

  2. Humans

  3. Marsupials

  4. Bandicoot

  5. All of the above


Correct Option: C
Explanation:

In most marsupials, the allantois is avascular, having no blood vessels  but still serves the purpose of storing nitrogenous (NH3) waste.

The eyes begin to develop at the end of ______.

  1. 4th week of pregnancy

  2. 8th week of pregnancy

  3. 12th week of pregnancy

  4. 24th week of pregnancy

  5. None of the above


Correct Option: A
Explanation:

The eye begins to develop as a pair of optic vesicles on each side of the forebrain at the end of the 4th week of pregnancy.

Which of the following twins are formed when two sperms fertilize one ovum, forming a triploid and then splitting?

  1. Identical twins

  2. Polar twins

  3. Sesquizygotic twins

  4. Fraternal twins

  5. None of the above


Correct Option: C
Explanation:

Sesquizygotic twins: where two sperm fertilize  one ovum, forming a triploid, and then splitting.

The amnion is not found in the placenta of which of the following animals?

  1. reptiles

  2. amphibians

  3. birds

  4. mammals

  5. none of the above


Correct Option: B
Explanation:

Amnion is absent in amphibians and fish.

Which of the following factors is/are responsible for increase in the likelihood of dizygotic twin pregnancies in woman? (i) She is of West African descent (especially Yoruba). (ii) She is between the age of 30 and 40 years. (iii) She is greater than average height and weight. (iv) She has had several previous pregnancies.

  1. She is of West African descent

  2. She is between the age of 30 and 40 years

  3. She is greater than average height and weight

  4. She has had several previous pregnancies.

  5. All of the above


Correct Option: E
Explanation:

Yes, it is correct.

Fertilization of a human egg and sperm usually occurs in which of the following parts of female reproductive tract?

  1. Vagina

  2. Cervix

  3. Uterus

  4. Ampulla

  5. None of the above


Correct Option: D
Explanation:

Human fertilization is the union of a human egg and sperm, usually occurring in the ampulla of the fallopian tube. The Fallopian tubes or oviducts are two tubes leading from the ovaries of female mammals into the uterus.

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