Description : Which one of the following is a matching pair of a body feature and the animal possessing it? (a) Ventral central – Leech nervous system (b) Pharyngeal gill slits – Chamaeleon absent in embryo (c) Ventral heart – Scorpion (d) Post-anal tail – Octopus
Last Answer : (a) Ventral central – Leech nervous system
Description : Crocodile and penguin are similar to whale and dogfish in which one of the following features? (a) Possess a solid single stranded central nervous system (b) Lay eggs and guard them till they hatch (c) Possess bony skeleton (d) Have gill slits at some stage
Last Answer : (d) Have gill slits at some stage
Description : Given below are four matchings of an animal and its kind of respiratory organ: (A) Silver fish – Trachea (B) Scorpion – Book lung (C) Sea squirt – Pharyngeal slits (D) Dolphin – Skin The correct matchings are (a) (A) and (B) (b) (A), (B) and (C) (c) (B) and (D) (d) (C) and (D).
Last Answer : (b) (A), (B) and (C)
Description : Which of the following characters is absent in all chordates? (a) Diaphragm (b) Coelom (c) Pharyngeal gill clefts (d) Dorsal nerve cord
Last Answer : (a) Diaphragm
Description : Assertion :- The aquatic mammals like Dolphins whales etc. do not contain gill slits. Reason : Their adaptation to aquatic life secondary.
Last Answer : Assertion :- The aquatic mammals like Dolphins whales etc. do not contain gill slits. Reason : Their ... . D. If both Assertion & Reason are false.
Description : Sharks and dogfishes differ from skates and rays because (a) gill slits are ventrally placed (b) head and trunk are widened considerably (c) distinct demarcation between body and tail (d) their pectoral fins distinctly marked off from cylindrical bodies
Last Answer : (d) their pectoral fins distinctly marked off from cylindrical bodies
Description : Sharks and dogfishes differ from skates and rays because (a) gill slits are ventrally placed (b) head and trunk are widened considerably (c) distinct demarcation between body and tail (d) their pectoral fins distinctly marked off from cylindrical bodies.
Last Answer : (d) their pectoral fins distinctly marked off from cylindrical bodies.
Description : Important characteristic that hemichordates share with chordates is (a) ventral tubular nerve cord (b) pharynx with gill slits (c) pharynx without gill slits (d) absence of notochord.
Last Answer : (b) pharynx with gill slits
Description : Match the following columns and select the correct option. Column-I Column-II (A) 6-15 pairs of gill slits (i) Trygon (B) Heterocercal caudal fin (ii) Cyclostomes (C) Air bladder (iii) Chondrichthyes (D) Poison sting (iv) Osteichthyes ... (i) (ii) (c) (iv) (ii) (iii) (i) (d) (i) (iv) (iii) (ii)
Last Answer : (a) (ii) (iii) (iv) (i)
Description : An important characteristic that Hemichordates share with Chordates is : (1) Ventral tubular nerve cord (2) Pharynx with gill slits (3) Pharynx without gill slits (4) Absence of notochord
Last Answer : (2) Pharynx with gill slits
Description : Which class of animals has 5-6 pairs of gill holes on their head ?
Last Answer : Answer : Chondrichthis class animals have 5-6 pairs of gill holes on their heads.
Description : Does Vertibrata become embryonic notochord ?
Last Answer : Answer : In the vertebrate phase, the embryonic notochord turns into a nerve.
Description : Which animal's body is made up of two embryonic cell layers ?
Last Answer : Answer : The body of a hydra is made up of two embryonic cell layers.
Description : How does pharyngeal pouches provide evidence for biological evolution?
Last Answer : It simply highly suggests that all organisms going through thisdevelopmental phase have common ancestry, thus are related on thetree of life.
Description : Embryological support for evolution was disapproved by (a) Karl Ernst von Baer (b) Alfred Wallace (c) Charles Darwin (d) Oparin.
Last Answer : (a) Karl Ernst von Baer
Description : What is the last stage of mitosis cell division ?
Last Answer : Telophase is the final stage of mitosis cell division.
Description : At what stage of mitosis new chromosomes are formed ?
Last Answer : Answer : New chromosomes are formed during the prophase stage of mitosis
Description : At what stage of division does the number of chromosomes in the offspring cell become half of the number of chromosomes in the mother cell ?
Last Answer : The number of chromosomes in the offspring cell formed during the division of miosis-1 is half of the number of chromosomes in the mother cell.
Description : At what stage of cell division does the nucleus get bigger ?
Last Answer : The size of the nucleus increases during the prophase stage of cell division.
Description : Which stage of mitosis cell division is chronic ?
Last Answer : Answer : The prophase stage of mitosis cell division is chronic.
Description : At what stage do each chromosome split vertically to form two chromatids ?
Last Answer : Each chromosome splits vertically to form two chromatids in the prophase step.
Description : At what stage of mitosis is the spindle device formed ?
Last Answer : Answer : The spindle instrument is formed in the pro-metaphase stage of mitosis.
Description : At what stage of mitosis do the chromosomes form VLJ or I ?
Last Answer : Answer : In the anaphase stage of mitosis, the chromosomes have VLJ or I shape.
Description : At what stage of mitosis division does the offspring chromosome form ?
Last Answer : In the anaphase stage of mitosis division, offspring chromosomes are formed.
Description : At what stage of cell division does each chromatid have a centimeter ?
Last Answer : In the anaphase step of cell division, each chromatid has one centimeter.
Description : At what stage of cell division does nucleolus almost disappear ?
Last Answer : The nucleolus is almost extinct during the pro-metaphase phase of cell division.
Description : At what stage of mitosis cell division does half of the chromosome move towards the North Pole and half towards the South Pole ?
Last Answer : Answer : In the anaphase stage of mitosis cell division, half of the chromosomes move towards the North Pole and half towards the South Pole.
Description : Which stage of mitosis cell division is short-lived ?
Last Answer : The pro-metaphase phase of mitosis cell division is short-lived.
Description : At what stage of mitosis do the chromosomes resemble the English alphabet J ?
Last Answer : The chromosomes in the anaphase stage of mitosis are like the English alphabet J.
Description : At what stage do the offspring chromosomes come to the opposite pole ?
Last Answer : Answer : The offspring chromosomes come to the opposite pole in the step of telophase.
Description : At what stage of mitosis division do the chromosomes become the shortest and thickest ?
Last Answer : In the metaphase stage of mitosis division, the chromosomes become the shortest and thickest.
Description : Netocord is found only in Larda stage in which sub-episode animal ?
Last Answer : Answer : Netocords are found only in the larda stage in the Urochordata subfamily .
Description : The infective stage to humans in schistosomiasis is (a) the adult (b) miracidum (c) Sporocyst (d) cercaria
Last Answer : (b) miracidum
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 : Study the given figure below and answer the question that follow important-questions-for-class-12-biology-cbse-fertilisation-pregnancy-and-embryonic-development-t-33-3 (i)Name the stage of human embryo the ... implantation in the uterus. (iv)Where are the stem cells located in this embryo? -Biology
Last Answer : (i)The stage is blastocyst. (ii) A—Trophoblast. It helps in attachment to endometrium during implantation and provides nourishment to developing embryo. (iii) Inner cell mass acts as precursor to embryo ... into ectoderm and endoderm. (iv) Stem cells are located in inner cell mass of embryo.
Description : Name the embryonic stage that gets implanted in the uterine wall of a human female. -Biology
Last Answer : Blastocyst gets implanted in the uterine wall.
Description : in which of the following the notochord is present in embryonic stage
Last Answer : in which of the following the notochord is present in embryonic stage A. All chordates B. Some chordates C. Vertebrates D. Non- chordates
Description : In which stage of development the embryonic cells form the germinal layers by the movement
Last Answer : In which stage of development the embryonic cells form the germinal layers by the movement A. Morula B. Blastula C. Gastrula D. Zygote
Description : Movement of blastomers usually seen in which embryonic stage :-
Last Answer : Movement of blastomers usually seen in which embryonic stage :- A. Morula B. Blastula C. Gastrula D. In all embryonic stages
Description : Three germ layers are formed during which stage of embryonic development :-
Last Answer : Three germ layers are formed during which stage of embryonic development :- A. Morula B. Blastula C. Gastrula D. In any two stages
Description : Assertion : Mucoid connective tissue is called as embryonic tissue. Reason : Mucoid connective tissue is mainly found in enbryonic stage .
Last Answer : Assertion : Mucoid connective tissue is called as embryonic tissue. Reason : Mucoid connective tissue is ... D. If both Assertion & Reason are false.
Description : What is the cell division during the first stage of the embryonic development called ?
Last Answer : How is this stage characterized? The cell division in the first stage of the embryonic developments is called cleavage, or segmentation. In this stage, mitosis occurs from the zygote forming the new embryo.
Description : What are the cells produced in the first stage of the embryonic development called ?
Last Answer : The cells that resulted from the cleavage (the first stage of the embryonic development) are called blastomeres. In this stage the embryo is called morula (similar to a “morus”, mulberry).
Description : After the blastula stage what is the following stage of the embryonic development ?
Last Answer : How is the passage from blastula to the next stage called? The blastula turns into gastrula in a process known as gastrulation.
Last Answer : How is the passage from blastula to the next stage called? The blastula turns into gastrula in a process known as gastrulation. Image Diversity: gastrula
Last Answer : The cells that resulted from the cleavage (the first stage of the embryonic development) are called blastomeres. In this stage the embryo is called morula (similar to a “morus”, mulberry). Image Diversity: morula
Description : How are the main classes of arthropods classified according to the presence of larval stage in their embryonic development?
Last Answer : In crustaceans there are species with direct and others with indirect development. In insects there are species without larval stage (ametabolic insects), others undergoing indirect ... while holometabolic insects undergo complete metamorphosis. Phylum Arthropoda - Image Diversity: metamorphosis
Description : The subphylum in which notochord is restricted only to the embryonic stage is
Last Answer : vertebrata.
Description : In which of the following, notochord is present in embryonic stage? (a) All chordates (b) Some chordates (c) Vertebrates (d) Non chordates
Last Answer : (a) All chordates