Description : Retina contains this photo sensitive pigment. (A) Rhodopsin (B) Opsin (C) Retinol (D) Malanin
Last Answer : Answer : A
Description : In the chemistry of vision in mammals, the photosensitive substance is called (a) rhodopsin (b) melanin (c) sclerotin (d) retinol.
Last Answer : (a) rhodopsin
Description : Photosensitive compound in human eye is made up of (a) opsin and retinol (b) transducin and retinene (c) guanosine and retinol (d) opsin and retinal.
Last Answer : (d) opsin and retinal.
Description : Rhodopsin contains opsin and (A) 11-cis-retinal (B) 11-trans-retinal (C) All-cis-retinal (D) All trans-retinal
Description : The pigment which gives colour to the human skin is – (1) Melanin (2) Rhodopsin (3) Iodopsin (4) Anthocyanin
Last Answer : (1) Melanin Explanation: Human skin color is primarily due to the presence of melanin in the skin. Skin color ranges from almost black to white with a pinkish tinge due to blood vessels underneath. In animals melanin pigments are derivatives of the amino acid tyrosine.
Description : The pigment which gives colour to the human skin is (1) Melanin (2) Rhodopsin (3) Iodopsin (4) Anthocyanin
Last Answer : Melanin
Description : Which one of the following is the correct difference between rod cells and cone cells of our retina? Rod cells Cone cells (a) Overall Vision in poor Colour vision function light and detailed ... of retina all over retina (c) Visual acuity High Low (d) Visual pigment Iodopsin Rhodopsin contained
Last Answer : (a) Overall Vision in poor Colour vision function
Description : Which of the following statements regarding Vitamin A is true? (A) It is not an essential Vitamin (B) It is related to tocopherol (C) It is a component of rhodopsin (D) It is also known as Opsin
Last Answer : Answer : C
Description : The following conditions are required for rhodopsin regeneration: a. NADPH b. darkness c. splitting of all trans-retinal from the opsin d. all above
Last Answer : all above
Description : The non-protein part of rhodopsin is (A) Retinal (B) Retinol (C) Carotene (D) Repsin
Description : On exposure to light rhodopsin forms (A) All trans-retinal (B) Cis-retinal (C) Retinol (D) Retinoic acid
Description : Non-protein part of rhodopsin is (A) Retinal (B) Retinol (C) Carotene (D) Repsin
Description : Retinol isomerase is present in (A) Retina (B) Liver (C) Both (A) and (B) (D) None of these
Last Answer : Answer : B
Description : $ Rhodopsin of rod cells and iodospin of cone cells of retina are proteins ! Myosine and Actin are contractile proteins
Last Answer : $ Rhodopsin of rod cells and iodospin of cone cells of retina are proteins ! Myosine and Actin are ... wrong D. If both As and R are wrong.
Description : The following are true about dark adaptation: a. only regeneration of rhodopsin is responsible b. adaptation usually takes about 20 minutes c. dilatation of pupil plays a part in dark adaptation d. it is better with the fovea than the peripheral retina
Last Answer : dilatation of pupil plays a part in dark adaptation
Description : Which one of the following statements is not correct? (a) Retinal is the light absorbing portion of visual photopigments. (b) In retina the rods have the photopigment rhodopsin while cones have three ... a derivative of vitamin C. (d) Rhodopsin is the purplish red protein present in rods only.
Last Answer : (c) Retinal is a derivative of vitamin C.
Description : Melanin pigment protects from which of the following radiations ?
Last Answer : Melanin pigment protects from which of the following radiations ? A. X-rays B. Infra-red rays C. Visible rays D. UV rays
Description : The brown-black pigment of the skin that is transferred to other epidermal cells and gives the skin its color is called A. albumin B. collagen C. keratin D. melanin
Last Answer : Ans: D
Description : True statements about chloroquine include: a. is safer than hydroxychloroquine at equivalent dose b. can cause corneal deposition c. causes posterior subcapsular cataract d. chloroquine is bound to the melanin of the retinal pigment epithelium e. causes reversible toxic maculopathy
Last Answer : can cause corneal deposition
Description : Hormones thyroxine, adrenaline and the pigment melanin are formed from (a) tyrosine (b) proline (c) tryptophan (d) glycine.
Last Answer : (a) tyrosine
Description : A person deficient in Rhodopsin (visual pigment) should take -
Last Answer : A person deficient in Rhodopsin (visual pigment) should take - A. Tomatoes B. Radish C. Carrots D. Guavas
Description : The purplish red pigment rhodopsin contained in the rods type of photoreceptor cells of the human eye, is a derivative of
Last Answer : The purplish red pigment rhodopsin contained in the rods type of photoreceptor cells of the human eye, is a ... Vitamin B 1 C. Vitamin C D. Vitamin D
Description : The ability of the eye to see in the dark, is due to the production of a purple pigment known as (1) Carotene (2) Rhodopsin (3)Iodopsin (4) Retinene
Last Answer : (4) Retinene Explanation: Retinene-1 is better known as retinaldehyde or simply retinal and is fundamental in the transduction of light into visual signals in the photoreceptor level of the retina (known as the visual cycle). Retinene-2 is more formally known as dehydroretinaldehyde.
Description : The ability of the Eye to see in the dark, is due to the production of a purple pigment known as----? A. Carotene B. Rhodopsin C. Iodopsin D. Retinene (Answer)
Last Answer : D. Retinene (Answer)
Description : Rhodopsin: a. is a red pigment b. is least sensitive to red light c. is regenerated when the eyes are closed d. all above
Description : The retinal pigment epithelium (RPE): a. is sensitive to hypervitaminosis A b. isomerizes all-trans-retinal to 11-cis-retinol c. does not undergo mitosis in response to injury d. secrets the outer layer of the basal lamina that forms the Bruch's membrane.
Last Answer : isomerizes all-trans-retinal to 11-cis-retinol
Description : The retinal pigment epithelium cells: a. esterify and store excess retinol b. transport retinol binding protein from blood to subretinal space c. are secured laterally to each other by tight junction d. all above
Description : The ability of the eye to see in the dark, is due to the production of a purple pigment known as (1) Carotene (2) Rhodopsin (3) Iodopsin (4) Retinene
Last Answer : Retinene
Description : In which part of the eye lies the pigment that decides the colour of the eyes of a person--? A. Retina B. Iris (Answer) C. Cornea D. Pupal
Last Answer : B. Iris (Answer)
Description : Regarding retinal metabolism: a. insulin is essential for the uptake of glucose by the retina b. anaerobic metabolism predominates c. the pigment retinal epithelium stores glycogen and supplies the need of the retina d. the demand of oxygen is met entirely by the central retinal artery
Last Answer : anaerobic metabolism predominates
Description : With regard to the blood retina barrier: a. the outer blood retina is formed by the retinal pigment epithelium cells and their junctions b. the blood retina barrier is typically defective in the ... fluid and anions from the extracellular space of the retina into the circulation d. all above
Description : The following structures are of ectodermal origin: a. the retina and its retinal pigment epithelium b. iris stroma c. the sclera d. the ciliary muscle e. the corneal stroma
Last Answer : the retina and its retinal pigment epithelium
Description : The cells of the retinal pigment epithelium: a. are of mesenchymal origin b. are shorter at the fovea than else where in the retina c. have intracellular melanosomes d. regenerate visual pigment e. form the inner outer blood-retina barrier
Last Answer : have intracellular melanosome
Description : In retinal detachment, fluid accumulates between: a. Outer plexiform layer and inner nuclear layer. b. Neurosensory retina and layer of retinal pigment epithelium c. Nerve fiber layer and rest of retina. d. Retinal pigment epithelium and Bruch’s membrane.
Last Answer : ANSWER: B
Description : Prosthetic group in cone cell phototreceptors is (A) Iodine (B) Opsin (C) 11-cis-retinal (D) all-trans-retinal
Description : MSH causes (A) Dispersal of melanin granules in melanocytes (B) Increase in melanin concentration in melanocytes (C) Decerease in melanin concentration in melanocytes (D) Increase in number of melanocytes
Description : The highest concentration of cystine can be found in (A) Melanin (B) Chondroitin sulphate (C) Myosin (D) Keratin
Last Answer : Answer : D
Description : Formation of melanin from tyrosine requires the action of (A) Dopa decarboxylation (B) Diamine oxidase (C) Peroxidase (D) Tyrosinase
Description : DOPA is an intermediate in the synthesis of (A) Thyroid hormones (B) Catecholamines (C) Melanin (D) Catecholamines and melanin
Description : All the following statements about phenylketonuria are correct except (A) Phenylalanine cannot be converted into tyrosine (B) Urinary excretion of phenylpyruvate and phenyllactate is increased (C) It ... diet (D) It leads to decreased synthesis of thyroid hormones, catecholamines and melanin
Description : Tryptophan could be considered as precursor of (A) Melanotonin (B) Thyroid hormones (C) Melanin (D) Epinephrine
Description : The fo l low ing substances are ce l l inclusions except (A) Melanin (B) Glycogen (C) Lipids (D) Centrosome
Last Answer : D
Description : cAMP is so called because it is formed during (A) TCA cycle (B) Urea cycle (C) Rhodopsin cycle (D) It has a cyclic structure
Description : The following form of vitamin A is used in the visual cycle: (A) Retinol (B) Retinoic acid (C) Retinaldehyde (D) Retinyl acetate
Description : Retinol and Retinol binding protein are bound with this protein: (A) Albumin (B) Prealbumin (C) α-globulin (D) β-globulin
Description : Retinol and retinol –binding protein (RBP) bound with this protein: (A) Albumin (B) Prealbumin (C) α2-globulin (D) β-globulin
Description : Dictary deficiency of this vitamin leads to night blindness: (A) Retinol (B) Niacin (C) Ascorbic acid (D) Cholecalciferol VITAMINS 125
Description : Retinol is transported to the blood as retinol attached to (A) α1-globulin (B) α2-globulin (C) β-globulin (D) γ-globulin
Description : Retinal is reduced to retinol by retinene reductase in presence of the coenzyme (A) NAD+ (B) NADP+ (C) NADH + H+ (D) NADPH + H+
Description : Retinoic acid is involved in the synthesis of (A) Rhodopsin (B) Iodopsin (C) Porphyrinopsin (D) Glycoproteins