Description : The number of thick myofilaments (myosin) surrounding Single thin myofilament (actin) are
Last Answer : The number of thick myofilaments (myosin) surrounding Single thin myofilament (actin) are A. 3 B. 6 C. 2 D. 4
Description : With reference to the skeletal muscle myofilaments a. actin is the major constituent of thin filaments b. myosin and tropomyosin combine to form the thick filaments c. troponin is a constituents of thin filaments d. tropomyosin prevents the interaction of actin and myosin in the resting state
Last Answer : actin is the major constituent of thin filaments
Description : Sliding filament theory can be best explained as (a) actin and myosin filaments do not shorten but rather slide pass each other (b) when myofilaments slide pass each other, myosin filaments shorten ... filaments do not shorten (d) actin and myosin filaments shorten and slide pass each other.
Last Answer : (a) actin and myosin filaments do not shorten but rather slide pass each other
Description : Microtubules consist of helically stacked molecules of the protein (A) Actin (B) Myosin (C) Keratin (D) Tubulin
Last Answer : (D) Tubulin
Description : Progesterone is transported in blood by (A) Transcortin (B) Sex hormone binding globulin (C) Albumin (D) Testosterone estrogen binding globulin
Last Answer : Answer : A
Description : Which of the following hormones will allow us to react to emergency situations? A) estrogen B) progesterone C) testosterone D) cortisol E) norepinephrine
Last Answer : E) norepinephrine
Description : Myosin bridges can be prevented from combining actin by two regulator proteins in resting muscle by (a) troponin (b) myofibril (c) troponin and tropomyosin (d) natural inhibiting proteins
Last Answer : Ans:(c)
Description : The contractile proteins in a muscle are (1) Actin and Myosin (2) Actin and Tropomyosin (3) Myosin and Troponin (4)Troponin and Tropomyosin
Last Answer : (1) Actin and Myosin Explanation: Muscle fibers or myofibrils are formed of three types of proteins which are (1) contractile, (2) regulatory, and (3) structural. Contractile proteins are the force ... are Actin which is part of thin filament and Myosin, which is part of the thick filament.
Description : Which one of the following is the correct matching of three items and their grouping category? Items Group (a) Ilium, ischium, Coxal bones of pelvic girdle pubis (b) Actin, myosin, Muscle proteins rhodopsin (c) Cytosine, uracil, Pyrimidines thiamine (d) Malleus, incus, Ear ossicles cochlea
Last Answer : (a) Ilium, ischium, Coxal bones of pelvic girdle pubis
Description : The major fibrous proteins are: a) peptone and edestin b) glutelin and leucine c) valine and lysine d) myosin and actin
Last Answer : ANSWER: D -- Myosin and Actin
Description : The organic portion of bone consists of which one of the following proteins. a) fibrin b) collagen c) actin d) myosin
Last Answer : ANSWER: B -- COLLAGEN
Description : The contractile proteins in a muscle are (1) Actin and Myosin (2) Actin and Tropomyosin (3) Myosin and Troponin (4) Troponin and Tropomyosin
Last Answer : Actin and Myosin
Description : Which of the following hormones is primarily responsible for stimulating the production of progesterone? a) Luteinizing hormone Luteinizing hormone is released by the pituitary gland. b) Follicle-stimulating ... , are involved in early development of the follicle and also affect the female libido.
Last Answer : a) Luteinizing hormone Luteinizing hormone is released by the pituitary gland.
Description : Cholesterol, testosterone, and estrogen are all examples of: a) proteins b) steroids c) nucleic acids d) alcohols
Last Answer : ANSWER: B -- STEROIDS
Description : Which one of the following pairs of chemical substances, is correctly categorised? (a) Calcitonin and thymosin - Thyroid hormones (b) Pepsin and prolactin - Two digestive enzymes secreted in ... and myosin - Complex proteins in striated muscles (d) Secretin and rhodopsin - Polypeptide hormones
Last Answer : (c) Troponin and myosin - Complex proteins in striated muscles
Description : Myosin is one of two proteins that make up the myofibrils of striated muscles. Name the other protein.
Last Answer : ANSWER: Actin
Description : A protein having both structural and enzymatic traits is (A) Myosin (B) Collagen (C) Trypsin (D) Actin
Description : The H-disk in the skeletal muscle fibre is due to (a) the absence of myofibrils in the central portion of Aband (b) the central gap between myosin filaments in the Aband Questions (c) the ... myosin filaments in the A-band (d) birefringence of myosin filaments in the central portion of A-band
Description : The protein present in the finger nail is (1) Actin (2) Myosin (3) Globin (4) Keratin
Last Answer : (4) Keratin Explanation: Keratin is a fibrous protein making up most cells found in our nails and hair and the epidermis layer of our skin. It also makes up fish scales and crustacean shells, bird feathers and beaks, and animal horns and hooves.
Description : In the skeletal muscle: a. myosin is found in the thick filament b. the thin filament contains actin and troponin c. during stimulus excitation calcium ions are derived from the serum d. tropomyosin masks the myosin-combining sites on the actin
Last Answer : tropomyosin masks the myosin-combining sites on the actin
Description : The following are true about the smooth muscle cells: a. presence of a striated appearance b. do not contain actin and myosin c. spontaneous muscle contraction d. mitochondria are absent
Last Answer : spontaneous muscle contraction
Description : The H-zone in the skeletal muscle fibre is due to (a) the central gap between actin filaments extending through myosin filaments in the A-band (b) extension of myosin filaments in the central portion ... the central portion of A-band (d) the central gap between myosin filaments in the A-band.
Last Answer : (a) the central gap between actin filaments extending through myosin filaments in the A-band
Description : Calcium is important in skeletal muscle contraction because it (a) binds to troponin to remove the masking of active sites on actin for myosin (b) activates the myosin ATPase by binding to it ... filament (d) prevents the formation of bonds between the myosin cross bridges and the actin filament.
Last Answer : (a) binds to troponin to remove the masking of active sites on actin for myosin
Description : Mitotic spindle is mainly composed of which protein? (a) Actin (b) Myosin (c) Actomyosin (d) Myoglobin
Last Answer : c) Actomyosin
Description : Calcium is important in skeletal muscle contraction because it :- (1) binds to troponin to remove the masking of active sites on actin for myosin. (2) activates the myosin ATPase by binding to ... filament. (4) prevents the formation of bonds between the myosin cross bridges and the actin filament.
Last Answer : (1) binds to troponin to remove the masking of active sites on actin for myosin.
Description : The phase of contraction of a muscle occurs when: a) tropomyosin binds and releases actin b) myosin binds and releases actin c) actin binds and releases myosin d) none of the above
Last Answer : ANSWER: B -- MYOSIN BINDS AND RELEASES ACTIN
Last Answer : Keratin
Description : A common intermediate in the synthesis of cortisol and aldosterone is (A) Progesterone (B) Testosterone (C) Estradiol (D) None of these
Description : In the biosynthesis of testosterone the rate limiting step is conversion of (A) Cholesterol to pregnenolone (B) Pregnenolone to progesterone (C) Progesterone to 17 α-hydroxy progesterone (D) 17 α-Hydroxy progesterone to androstenedione
Description : 3-β-Hydroxysteroid dehydrogenase and ∆5,4 isomerase catalyse the conversion of the weak androgen DHEA to (A) Androstenedione (B) Testosterone (C) Progesterone (D) Estrone
Description : The defect in adrenal cortex responsible for lack of glucocorticoids and mineralcorticoids is (A) Androstenedione deficiency (B) 17 α -OH progesterone deficiency (C) C-21 hydroxylase deficiency (D) Testosterone deficiency HORMONE METABOLISM 209
Last Answer : Answer : C
Description : Cyclic AMP is formed from ATP by the enzyme adenylate cyclase which is activated by the hormone: (A) Insulin (B) Epinephrine (C) Testosterone (D) Progesterone
Last Answer : B
Description : The hormone used as an oral contraceptive is – (1) Cortisone (2) Progesterone (3) Testosterone (4) Aldesterone
Last Answer : (2) Progesterone Explanation: It was discovered relatively long ago (1930's) that injections of progesterone were effective as a contraceptive in preventing pregnancies. Progesterone is used as a ... for creating a hostile environment for fertilization and not allowing sperm to enter the egg.
Description : Secretion of progesterone by corpus luteum is initiated by (a) testosterone (b) thyroxine (c) MSH (d) LH.
Last Answer : d) LH.
Description : The hormone used as an oral contraceptive is : (1) Cortisone (2) Progesterone (3) Testosterone (4) Aldesterone
Last Answer : Progesterone
Description : Does nipple/aureola size in men have anything to do with estrogen/testosterone?
Last Answer : Well now that the original question has been ammended, my previous comment would be redundant. So, as Emily Litella used to say: …never mind… :)
Description : Estrogen and testosterone are steroid hormones, and most likely bind to
Last Answer : Estrogen and testosterone are steroid hormones, and most likely bind to A. Cytoplasmic receptors ... receptors D. G-protein liked membrane receptors
Description : Testosterone is transported in blood by (A) Transcortin (B) Testosterone binding globulin (C) Testosterone estrogen binding globulin (D) Albumin
Description : Location and secretion of Leydig’s cells are (a) liver-cholesterol (b) ovary-estrogen (c) testis-testosterone (d) pancreas-glucagon.
Last Answer : (c) testis-testosterone
Description : Occurrence of Leydig’s cells and their secretion is (a) ovary and estrogen (b) liver and cholesterol (c) pancreas and glucagon (d) testis and testosterone.
Last Answer : d) testis and testosterone.
Description : Duodenum has characteristic Brunner’s gland which secrete two hormones called (a) kinase, estrogen (b) secretin, cholecystokinin (c) prolactin, parathormone (d) estradiol, progesterone
Last Answer : (b) secretin, cholecystokinin
Description : What is the role of estrogen and progesterone? -Biology
Last Answer : answer:
Description : Level of estrogen and progesterone are minimum at the time of
Last Answer : Level of estrogen and progesterone are minimum at the time of A. Folicular phase B. Ovulation C. Secretory phase D. Onset of menstrual phase.
Description : Low level of progesterone and estrogen stimulates production of
Last Answer : Low level of progesterone and estrogen stimulates production of A. FSH-RH B. LH C. GH D. All the above
Description : Assertion : If fertilization dies not occur than the corpus luteum begins to degenerate . Reason : The levels of progesterone and estrogen decline due
Last Answer : Assertion : If fertilization dies not occur than the corpus luteum begins to degenerate . Reason : The ... D. If both Assertion & Reason are False.
Description : Placenta secretes all of the following except (A) FSH (B) Progesterone (C) Estrogen (D) Chorionic gonadotropin HORMONE METABOLISM 225
Description : A hormone used for detection of pregnancy is (A) Estrogen (B) Progesterone (C) Oxytocin (D) Chorionic gonadotropin
Last Answer : Answer : D
Description : Women become susceptible to osteoporosis after menopause due to decreased (A) Secretion of Parathormone (B) Conversion of vitamin D into calcitriol (C) Secretion of estrogen (D) Secretion of progesterone
Description : Zona glomerulosa of adrenal cortex synthesises (A) Glucocorticoids (B) Mineralocorticoids (C) Androgens (D) Estrogen and progesterone HORMONE METABOLISM 223