Description : Explain the events that occur during fertilisation of an ovum in humans. How is it that only one sperm enters the OVUm? -Biology
Last Answer : (i)In humans, the fertilisation of ovum takes place in ampullary-isthmic junction of Fallopian tube. The events that occur during the process of fertilisation are: (a) The sperm reaches the ... that blocks the entry of additional sperms. This ensures that only one sperm can fertilise an ovum
Description : What happens during fertilisation in humans after many sperms reach close to the ovum? (a) Secretions of acrosome helps one sperm enter cytoplasm of ovum through zona pellucida. (b) All sperms except ... all the sperms except one. (d) Only two sperms nearest the ovum penetrate zona pellucida.
Last Answer : (a) Secretions of acrosome helps one sperm enter cytoplasm of ovum through zona pellucida.
Description : Extrusion of second polar body from egg occurs (a) simultaneously with first cleavage (b) after entry of sperm but before fertilisation (c) after fertilisation (d) before entry of sperm into ovum.
Last Answer : (b) after entry of sperm but before fertilisation
Description : From a to d which of the following statements are correct ? (a) Fertilisation can occur only if the ovum and sperm are transported simultaneously to t
Last Answer : From a to d which of the following statements are correct ? (a) Fertilisation can occur only if the ovum and sperm ... b and c C. c and d D. b and d
Description : Capacitation refers to changes in the (a) ovum after fertilisation (b) sperm after fertilisation (c) sperm before fertilisation (d) ovum before fertilisation.
Last Answer : (c) sperm before fertilisation
Description : Which one of the following statements about human sperm is correct? (a) Acrosome has a conical pointed structure used for piercing and penetrating the egg, resulting in fertilisation. (b) The ... a sensory structure leading the sperm towards the ovum. (d) Acrosome serves no particular function
Last Answer : (b) The sperm lysins in the acrosome dissolve the egg envelope facilitating fertilisation.
Description : Fertilisation in humans is practically feasible only if (a) the ovum and sperms are transported simultaneously to ampullary-isthmic junction of the cervix (b) the sperms are transported ... the ovum and sperms are transported simultaneously to ampullary-isthmic junction of the fallopian tube.
Last Answer : (d) the ovum and sperms are transported simultaneously to ampullary-isthmic junction of the fallopian tube.
Description : Grey crescent is the area (a) at the point of entry of sperm into ovum (b) just opposite to the site of entry of sperm into ovum (c) at the animal pole (d) at the vegetal pole.
Last Answer : (b) just opposite to the site of entry of sperm into ovum
Description : The second maturation division of the mammalian ovum occurs (a) shortly after ovulation before the ovum makes entry into the fallopian tube (b) until after the ovum has been penetrated by a sperm ... with that of the ovum (d) in the Graafian follicle following the first maturation division.
Last Answer : (b) until after the ovum has been penetrated by a sperm
Description : Which of the following approaches does not give the defined action of contraceptive? (a) Hormonal contraceptives Prevent/retard entry of sperms, prevent ovulation and fertilisation (b) ... devices Increase phagocytosis of sperms, suppress sperm motility and fertilising capacity of sperms
Last Answer : (b) Vasectomy Prevents spermatogenesis
Description : Cri-du-chat syndrome in humans is caused by the (a) trisomy of 21st chromosome (b) fertilisation of an XX egg by a normal Y-bearing sperm (c) loss of half of the short arm of chromosome 5 (d) loss of half of the long arm of chromosome 5.
Last Answer : (c) loss of half of the short arm of chromosome 5
Description : Endosperm is formed during the double fertilisation by (a) two polar nuclei and one male gamete (b) one polar nuclei and one male gamete (c) ovum and male gamete (d) two polar nuclei and two male gametes.
Last Answer : (a) two polar nuclei and one male gamete
Description : (i) Mention the event that induces the completion of the meiotic division of the secondary oocyte. (ii) Trace the journey of the ovum from the ovary, its fertilisation and further development until the implantation of the embryo. -Biology
Last Answer : (i)Secondary oocyte completes meiosis-ll only when a sperm enters its cytoplasm. It forms a larger cell, the ootid and a small cell, the second polar body. (ii)The secondary oocyte is ... and inner cell mass.The trophoblast attacheds to endometrium (implantation) and blastocyst gets embedded in it.
Description : (i)Explain the events taking place at the time of fertilisation of an ovum in a human female. (ii)Trace the development of the zygote up to its implantation in the uterus. (iii)Name and draw a labelled sectional view of the embryonic stage that gets implanted. -Biology
Last Answer : (i)In humans, the fertilisation of ovum takes place in ampullary-isthmic junction of Fallopian tube. The events that occur during the process of fertilisation are: (a) The sperm reaches the ... endometrium of the uterus. This is called implantation.(iii) Blastocyst stage implants in the uterus.
Description : The stage transferred into the uterus after induced fertilisation of ovum in the laboratory is (a) embryo at 4 blastomeres stage (b) embryo at 2 blastomeres stage (c) morula (d) zygote.
Last Answer : (c) morula
Description : The term Test Tube Baby' implies (a) Fertilisation of ovum takes place I the test tube but it develops in uterus (b) Fertilisation of ovum takes place in the test tube and develops in ... uterus but develops in the test tube (d) Fertilisation takes place in uterus and embryo develops in uterus
Last Answer : Ans:(a)
Description : Sex is determined in human beings (a) by ovum (b) at time of fertilisation (c) 40 days after fertilisation (d) seventh to eight week when genitals differentiate in fetus.
Last Answer : (b) at time of fertilisation
Description : The technique called Gamete Intra Fallopian Transfer (GIFT) is recommended for those females (a) who cannot produce an ovum (b) who cannot retain the fetus inside uterus (c) whose cervical ... narrow to allow passage for the sperms (d) who cannot provide suitable environment for fertilisation.
Last Answer : (a) who cannot produce an ovum
Description : Which one of the following is the most likely root cause why menstruation is not taking place in regularly cycling human female? (a) Maintenance of the hypertrophical endometrial lining (b) ... the blood stream (c) Retention of well-developed corpus luteum (d) Fertilisation of the ovum
Last Answer : (b) Maintenance of high concentration of sex- hormones in the blood stream
Description : In human beings after fertilisation , the structure which gets embedded in the wall of uterus is a) ovum b)embryo c)foetus d)zygote
Last Answer : b)embryo
Description : Which of the following statement about reproductions in human is correct. a) fertilisation takes place externally b) fertilisation takes place in the testes c) during fertilisation egg moves towards sperm d) fertilisation takes place in human female
Last Answer : d) fertilisation takes place in human female
Description : Identical twins are born when (a) Two sperms fertilise one ovum (b) Two sperms fertilise two ovums simultaneously (c) Open sperm fertilizes the ovum and zygote divides into two separate cells developing independently (d) One sperm fertilises two ovums
Last Answer : Ans:(c)
Description : In human beings, normally in which part, does the sperm fertilize the ovum? -Do You Know?
Last Answer : answer:
Description : What are both ovum and sperm ?
Last Answer : : Both ovum and sperm are haploid
Description : Fusion of sperm and ovum is
Last Answer : Fusion of sperm and ovum is A. Amphimixis B. Regeneratin C. Fertilization `rarr` Cleavage `rarr` Zygote ... `rarr` Gastrula. D. None of the above.
Description : Assertion : The nucleus of sperm fuses with the nucleus of ovum , before the formation of ootid . Reason : Diploid nuclear status of organism is essen
Last Answer : Assertion : The nucleus of sperm fuses with the nucleus of ovum , before the formation of ootid . ... . D. If both Assertion & Reason are False.
Description : Assertion : The acrosomal secretions of sperm , help it in entering in the cytoplasm of the ovum . Reason : It contains sperm lysin .
Last Answer : Assertion : The acrosomal secretions of sperm , help it in entering in the cytoplasm of the ovum . ... . D. If both Assertion & Reason are False.
Description : Assertion : Sperm formation continues even in old men but formation of ovum caeses in women around the age of fifty years . Reason : Human male having
Last Answer : Assertion : Sperm formation continues even in old men but formation of ovum caeses in women around the ... D. If both Assertion & Reason are False.
Description : Various changes in mammalian sperm which prepare it to fertilise the ovum are called :
Last Answer : Various changes in mammalian sperm which prepare it to fertilise the ovum are called : A. Capacitation B. Regeneration C. Growth D. None of these
Description : An abnormal human baby with ‘XXX’ sex chromosomes was born due to (a) fusion of two ova and one sperm (b) fusion of two sperms and one ovum (c) formation of abnormal sperms in the father (d) formation of abnormal ova in the mother.
Last Answer : (d) formation of abnormal ova in the mother.
Description : Meiotic division of the secondary oocyte is completed (a) prior to ovulation (b) at the time of copulation (c) after zygote formation (d) at the time of fusion of a sperm with an ovum.
Last Answer : (d) at the time of fusion of a sperm with an ovum.
Description : human beings, normally in which part, does the sperm fertilize the ovum?
Last Answer : Fallopian tube
Description : The primary mechanism of action of the combined estrogen-progestin oral contraceptive pill is: A. Production of cervical mucus hostile to sperm penetration B. Suppression of FSH and ... Making endometrium unsuitable for implantation D. Enhancing uterine contractions to dislodge the fertilized ovum
Last Answer : B. Suppression of FSH and LH release
Description : 9.Acrosome is important for ----------- . a)ATP production, b)Dissolving membrane of ovum, c)Motility of sperm, d)Nutrition of sperm
Last Answer : b)Dissolving membrane of ovum,
Description : Fertilization of the ovum by the sperm usually occurs in the: a) oviduct b) vagina c) uterus d) ovary
Last Answer : ANSWER: A -- OVIDUCT
Description : Where does fertilisation occur in humans? Explain the events that occur during this process. -Biology
Last Answer : In humans, the fertilisation of ovum takes place in ampullary-isthmic junction of Fallopian tube. The events that occur during the process of fertilisation are: (i) The sperm reaches the junction of ampulla ... and second polar body. (iv)Nucleus of sperm and of ovum fuses to form a diploid zygote.
Description : In case of a couple where the male is having a very low sperm count, which technique will be suitable for fertilisation? (a) Gamete Intracytoplasmic Fallopian Transfer (b) Artificial Insemination (c) Intracytoplasmic sperm injection (d) Intrauterine transfer
Last Answer : (b) Artificial Insemination
Description : In case of a couple where the male is having a very low sperm count, which technique will be suitable for fertilisation ? (1) Gamete intracytoplasmic fallopian transfer (2) Artificial Insemination (3) Intracytoplasmic sperm injection (4) Intrauterine transfer
Last Answer : (2) Artificial Insemination
Description : Explain the steps in the formation of an ovum from an oogonium in humans. or Suggest and explain any three Assisted Reproductive Technologies (ART) to an infertile couple. -Biology
Last Answer : Three reproductive techniques for sterile couple are: (i) In vitro fertilisation The fertilisation outside the body in almost similar conditions as that in the body followed by embryo transfer to the ... to form an embryo in the laboratory in which a sperm is directly injected into the ovum.
Description : The duration 19-21 days refers to: (1) incubation period of hen's egg (2) average life-span of a red blood cell in humans (3) the period of menstrual cycle soon after menstruation, during ... to occur (4) period of completion of one schizogony cycle of malarial parasite inside a red blood cell
Last Answer : (3) the period of menstrual cy-cle soon after menstruation, during which fertilisation is most likely to occur Explanation: The menstrual cycle is the scientific term for the physiological changes ... 21 days or more between a woman's shortest and longest cycle lengths is considered very irregular
Last Answer : the period of menstrual cycle soon after menstruation, during which fertilisation is most likely to occur
Description : Describe the post-zygotic events leading to implantation and placenta formation in humans. Mention any two functions of placenta. [All India 2010] or Explain the process of fertilisation in human female ... events in a sequential order up to implantation of the embryo. [Foreign 2010] -Biology
Last Answer : Post-zygotic events leading to implantation and placenta formation. After implantation of blastocyst, the finger-like projections called chorionic villi, appear on the trophoblast and is surrounded by ... acts as an endocrine gland and secretes hormones like hPL, hCG, oestrogen and progesterone.
Description : Which one of the following characteristics is common both in humans and adult frogs? (a) Four chambered heart (b) Internal fertilisation (c) Nucleated RBCs (d) Ureotelic mode of excretion
Last Answer : (c) Nucleated RBCs
Description : In what way is transparency ensured by a democratic system? -SST 10th
Last Answer : . Democracy ensures that the decision-making process is based on norms and procedures. . Citizens have the right and the means to examine the process of decision-making. . Democracy produces a government that follows procedures and is accountable to the people.
Description : Name the person who got people from village, ensured them jobs, helped them settle in cities and provided them money in times of need. -SST 10th
Last Answer : Jobber is the person who got people from village, ensured them jobs, helped them settle in cities and provided them money in times of need.
Description : In which two ways the Constitution has ensured the independence of the High Courts? -SST 10th
Last Answer : (i) By Security of Service, and (ii) Security of pay and allowances.
Description : Expenses need to be recorded in the period in which the associated revenues are recognised. This is to be ensured as per which one of the following accounting principles ? (A) Revenue recognition (B) Cost benefit (C) Matching (D) Periodicity
Last Answer : Answer: Revenue recognition
Description : Pick up the correct statement from the following: A. Hydrogen sulphide gas in excess, may cause corrosion of concrete sewers B. 4 ppm of Dissolved Oxygen (D.O.) is ensured before discharging the treated ... river C. Solubility of oxygen in sewage is 95% of that of distilled water D. All the above
Last Answer : ANS: D
Description : For efficient working of a sewer, it must be ensured that A. Minimum velocity of 0.45 m/sec, is maintained at its minimum flow B. A maximum velocity of 0.90 m/sec, is maintained at its maximum flow C. Both A. and B. D. Neither A. nor B.
Last Answer : ANS: C
Description : The correctness and accuracy of the transmitted message content is A. verified by the modem B. communications system C. determined by the sender and receiver D. ensured by use of digital technique
Last Answer : C. determined by the sender and receiver