Tag: reproduction in humans
Questions Related to reproduction in humans
Fraternal twins in humans are produced when
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Two sperms fertilize an ovum and the first two blastomeres separate from each other
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One sperm fertilizes an ovum and the first two blastomeres separate from each other
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Egg develop parthenogenetically and first two blastomeres separate from each other
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Two ova are fertilized simultaneously
Fraternal twins are also called as 'dizygotic'. This means there is fertilization of two seperate eggs(ova) by two individual sperms simultaneously. They are implanted in the uterine wall at the same time. They usually develop in two separate amniotic sacs. They are also called as 'biovular' since two eggs form two zygotes.
So, the correct is answer is 'Two ova are fertilized simultaneously'.
What are identical twins?
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Heterozygous
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Homozygous
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Monozygotic
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Dizygotic
Which are the two offspring developed in the same uterus but from fertilization of two different ova?
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Dizygotic twins
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Monozygotic twin
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Fraternal twins
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Both A and C
Dizygotic twins may occur if two or more oocytes are released in one cycle. If each is fertilized, dizygotic twins may result. Fertility drugs are a common cause for dizygotic twins, but other factors, like family history, maternal age or weight, can also lead to dizygotic twinning. Thus, the correct answer is option D.
Monozygotic twins develops from
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Different zygotes
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Different ova
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Different sperms
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Same zygote
- There are two types of twins, Fraternal or dizygotic twins, and monozygotic twins.
- When the zygote, during the cleavage, separates and forms two different cells and both of them grow individually as embryos, they form the monozygotic twins.
- Monozygotic twins are of the same sex.
- When 2 zygotes are fertilized by two different sperms they form the dizygotic twins.
- They can be of different sex.
Concordant type of twins are
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Free martins
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Dizygotic twins
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Monozygotic twins
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Both B and C
Structure connecting the fetus to placenta is ________________.
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Umbilical cord
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Amnion
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Yolk sac
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Chorion
Umbilical cord is a narrow, tube-like structure that connects the fetus to the placenta.Through this tube, nutrients and oxygen are supplied from the mother to the baby and waste products are removed from the baby.
Which of the following hormones is not a secretory product of human placenta?
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Human Chorionic Gonadotropin
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Prolactin
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Estrogen
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Progesterone
Prolactin is secreted by the anterior lobe of pituitary gland. After parturition, secretion and storage of milk in mammary glands is under the influence of this hormone.
Fetus gets nourishment and oxygen through _______________.
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Allantois
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Placenta
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Yolk sac
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Chorion
Placenta is an intimate connection between the fetus and uterine wall of the mother to exchange the materials. Food materials and oxygen pass from the mother's blood into the fetal blood and fetal excretory products diffuse into maternal blood through placenta.
In humans the shape of fully formed placenta is
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Cuboidal
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Columnar
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Pyramidal
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Discoidal
The human placenta is both metadiscoidal and monodiscoidal. Discoidal refers to the structure of the placenta and mono meaning there is only one disc. Metadiscoidal refers to the way the developing placenta becomes discoidal- the villi are scattered at first and then restricted to one disc, that means the placenta becomes mono-discoidal.
Mother's blood flows into the foetus through placenta
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True
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False