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 : 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 : 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 : Write the function of each of the following (i)Seminal vesicle (ii)Scutellum (iii)Acrosome of human sperm -Biology
Last Answer : (i)Seminal vesicle spermatogenesis It secretes an alkaline fluid that helps in neutralising the acidity of the vaginal tract and thereby increase the lifespan of sperms. Secretion of seminal vesicle is ... which help the sperm enter into the cytoplasm of the ovum and thus helps in fertilisation.
Description : Acrosome of sperm contains
Last Answer : Acrosome of sperm contains A. Hydrolytic enzymes B. DNA C. Fructose D. Mitochondria.
Description : In the absence of acrosome the sperm
Last Answer : In the absence of acrosome the sperm A. Cannot penetrate the egg B. Cannot get food C. Cannot get energy D. Cannot swim.
Description : Acrosome reaction of sperm is triggered by
Last Answer : Acrosome reaction of sperm is triggered by A. Capacitation B. Release of lysin C. Release of fertilizin D. Influx of `Na^(+)`
Last Answer : Acrosome of sperm contains A. Hyluronidase and acrosin B. Hyaluronic acid and acrosin C. Hippuric acid and uric acid D. Creatinine.
Description : Which part of the spermatid forms acrosome of sperm ?
Last Answer : Which part of the spermatid forms acrosome of sperm ? A. Mitochondria B. Golgi body C. Nucleus D. Lysosome
Description : Acrosome reaction in sperm is triggered by (a) capacitation (b) release of lysin (c) influx of Na+ (d) release of fertilizin.
Last Answer : (c) total
Description : Fertilizin is a chemical substance produced from (a) polar bodies (b) middle piece of sperm (c) mature eggs (d) acrosome.
Last Answer : (c) mature eggs
Description : Assertion: Cu-T and Cu-7 do not suppress sperm motility. Reason: Hormones released by them affect sperm motility.
Last Answer : Assertion: Cu-T and Cu-7 do not suppress sperm motility. Reason: Hormones released by them affect ... D. If both the assertion and resson are false.
Description : Cu ions released from copper-releasing intra uterine devices (IUDs) (a) make uterus unsuitable for implantation (b) increase phagocytosis of sperms (c) suppress sperm motility (d) prevent ovulation.
Last Answer : suppress sperm motility
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 : The function of copper ions in copper releasing IUDs is (a) they inhibit gametogenesis (b) they make uterus unsuitable for implantation (c) they inhibit ovulation (d) they suppress sperm motility and fertilising capacity of sperms.
Last Answer : (d) they suppress sperm motility and fertilising capacity of sperms.
Description : Which one of the following statements is false in respect of viability of mammalian sperm? (a) Sperm is viable for only up to 24 hours. (b) Survival of sperm depends on the pH of the ... ) Viability of sperm is determined by its motility. (d) Sperms must be concentrated in a thick suspension.
Last Answer : (a) Sperm is viable for only up to 24 hours.
Description : The function of copper ions in copper releasing IUD's is : (1) They inhibit gametogenesis (2) They make uterus unsuitable for implantation (3) They inhibt ovulation (4) The suppress sperm motility and fertilising capacity of sperms
Last Answer : (4) The suppress sperm motility and fertilising capacity of sperms
Description : 70. Which one of the following statements is false in respect of viability of mammalian sperm ? (1) Sperms must be concentrated in a thick suspension (2) Sperm is viable for only up to 24 hours ... the medium and is more active in alkaline medium (4) Viability of sperm is determined by its motility
Last Answer : Sperm is viable for only up to 24 hours
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 : How is the entry of only one sperm ensured into an ovum during fertilisation in humans? -Biology
Last Answer : During fertilisation, a sperm comes in contact with the zona pellucida layer of the ovum and induces changes (depolarisation) in the membrane that blocks the entry of additional sperms. This ensures that only one sperm can fertilise an ovum
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 : 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 : 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 : 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 : 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 : 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 : 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 : 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 : 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 : Which of the following statements are true of oxidants? A. In addition to their pathophysiologic roles in inflammation, injury, and infection, oxidants also have physiologic roles. B. Oxidants may ... involved the catalytic production of superoxide anion (O 2 ) by the enzyme xanthine oxidase.
Last Answer : Answer: ABCD DISCUSSION: Oxidants are reactive oxygen metabolites that have both physiologic and pathophysiologic roles. As potent oxidizing agents, oxidants are involved in cytochrome P ... leukocyte infiltration and activation, causing further tissue damage by the release of cytotoxic proteases
Description : Assertion : Normally monospermy occurs in most of animals . Reason : Vitelline membrane of ovum checks polyspermy .
Last Answer : Assertion : Normally monospermy occurs in most of animals . Reason : Vitelline membrane of ovum checks ... D. If both Assertion & Reason are False.
Description : Acrosome is made up of
Last Answer : Acrosome is made up of A. Mitochondria B. Centrioles C. golgi bodies D. Ribosomes.
Description : Which set of enzymes is found in the acrosome of mammalian spermatozoa :
Last Answer : Which set of enzymes is found in the acrosome of mammalian spermatozoa : A. Hyaluronidase , ... Hyaluronidase , CPE , Peptidase D. Hyaluronidase only
Description : Acrosome of spermatozoa is formed from :
Last Answer : Acrosome of spermatozoa is formed from : A. Lysosomes B. Golgi bodies C. Ribosome D. Mitochondria
Description : The acrosome plays a role in :-
Last Answer : The acrosome plays a role in :- A. Fusion of nuclei of gametes B. Motality of sperm C. Penetration of sperm into ovum D. All of the above
Description : Space between acrosome and nucleus is called :-
Last Answer : Space between acrosome and nucleus is called :- A. Nebenkern B. Perforatorium C. Nucleus of Pander D. Perivitelline space
Description : Acrosome formation in spermatogenesis occurs in which stage ?
Last Answer : Acrosome formation in spermatogenesis occurs in which stage ? A. First meiotic division B. Second meiotic division C. Growth phage D. Spermiogenesis
Description : The structure which helps in the nutrition of the Embryo is – (1) Yolk sac (2) Amniotic membrane (3) Crypts (4) Placenta
Last Answer : (1) Yolk sac Explanation: The yolk sac is a membranous sac attached to an embryo, providing early nourishment. It functions as the developmental circulatory system of the human embryo, ... It carries out transfer of nutrients in weeks 2 and 3 when the uteroplacental circulation is established
Description : Pick up the wrong statement. (a) Some fungi are edible. (b) Nuclear membrane is present in Monera. (c) Cell wall is absent in Animalia. (d) Protists have photosynthetic and heterotrophic modes of nutrition.
Last Answer : (b) Nuclear membrane is present in Monera.
Description : Archaebacteria differ from eubacteria in (a) cell membrane structure (b) mode of nutrition (c) cell shape (d) mode of reproduction.
Last Answer : (a) cell membrane structure
Description : The structure which helps in the nutrition of the Embryo is (1) Yolk sac (2) Amniotic membrane (3) Crypts (4) Placenta
Last Answer : Yolk sac
Description : In most metabolic pathways, all needed enzymes are arranged together in a multienzyme complex within a (A) Solution of ATP (B) Membrane (C) Quanternary protein (D) Coenzyme
Last Answer : Answer : B