The other strand, which has a polarity of 5' ® 3' is displaced, during transcription. Assertion: Holoblastic cleavage with almost equal sized blastomeres is a characteristic of placental animals.Reason: Eggs of most mammals, including humans, are of centrolecithal type. B) Mitochondria are called power house of a, cell because they produce large amount of, energy in the form of ATP., 31. Thus, terrestrial, herbivores are less productive than aquatic, herbivores., The number of species increases, the, community biomass increases and the, community's ratio of respiration to, photosynthesis increases during an, ecological succession. A) ECG consists of P-wave, QRS wave and Twave. PEP enzymes show high, affinity for CO2.
The contraction of, external intercostal muscles lifts up the ribs, and the sternum causing an increase in the, volume of the thoracic chamber in the, dorso-ventral axis. It stimulates the interstitial cells of, leydig (testis) to secrete the male sex, hormone testosterone and other androgen, to regulate the secondary sexual, characteristics., The follicle stimulating hormone (FSH) is, secreted by anterior pituitary. Assertion Reason Questions for Biology Chapter 24 Sexual Reproduction in Flowering Plants. A) Lysosomes are single membrane bound, small vesicles containing hydrolytic, enzymes in the form of minute crystalline, or semicrystalline granules of 0. Page 260: EBD_7166, 256,, 21. There is another type of genetic, material found in cells and viruses known, as ribonucleic acid (RNA). Glucagon acts, mainly on the liver cells (hepatocytes) and, stimulates glycogenolysis which also, contributes to a complex disorder called, diabetes mellitus., (c) Males have more stature than females, because of the action of male sex hormonetestosterone which is secreted by testis in, males.
Assertion: Both digested and semi-digested, food is absorbed by body surface in tapeworms., Reason: Tapeworms lack digestive organs., 25. Petals or, corolla constitute the upper or inner series, of accessory floral organs which are leaflike but brightly coloured to attract, pollinating animals. All are taxa, which, represent taxa at different levels., 39. Assertion reason question on grade 11 placentation english. Assertion: Flowering depends only on a, combination of light and dark exposure in some, plants., Reason: The site of perception of light or dark, duration are the shoot apices of plants., 23. Page 25: 21,, Plant Kingdom, 12.,, 13.,, 14.,, 15.,, 16., 17.,, 18.,, (c) The fusing gametes in the lower forms of, algae are similar in size, structure and, behaviour.
RNA, polymerase also known as DNA-dependent, RNA polymerase, is an enzyme that, produces primary transcript RNA., 40. A) Artificial insemination (AI) or intrauterine, insemination (IUI) is way of treating, infertility. Assertion: Ammonia is converted into nitrate, by soil bacteria like Nitrosomonas and, Nitrobacter., Reason: These nitrifying bacteria are, photoautotrophs., 26. B) The part of plant which is cultured is called, explant. Within the, chloroplast there is the membranous, system consisting of grana, the stroma, lamellae, and the fluid stroma. Assertion: In electron transport chain, there is, a loss of energy at each step., Reason: At each step of ETC, there are electron, carriers., 21. Assertion: In plant tissue culture somatic, embryos can be induced from any plant cell., Reason: Any viable plant cell can differentiate, into somatic embryos., [AIIMS 2003],, 225,, 40. A pivot joints allows movement,, 141,, primarily in one plane. Such gametes are called, isogametes. C) Organisms with lethal mutation bear lethal, genes that result in the death of the, individual which carries them. A, fruit formed without fertilisation, i. e., a, seedless fruit is called parthenocarpic fruit, e. Assertion reason question on grade 11 placentation list. g., banana., 60. A),, agriculture, so these areas have high, population density.
Page 252: EBD_7166, 248,, 11.,, 12., 13.,, 14.,, 15.,, Assertion- Reason in Biology, (c) Adult onset diabetes management is, possible by taking insulin at regular time, intervals, but insulin from other animals, could elicit immune response in body., Biotechnology has helped to overcome this, problem. The, membrane system is responsible for, trapping the light energy and also for the, synthesis of ATP and NADPH., (c) Anthocyanin pigments only give, colouration since the epidermal cells, mainly have potential colouring pigments., It is responsible for blue, red, pink and, purple colours, observed in different parts, of plants such as petals, stamens and fruits, etc., Anthocyanins are also important for, attracting insects for pollination and seed, dispersal. This, may be due to suppression of expression, of harmful recessive genes that are, expressed only in homozygous conditions., Inbreeding is mating of individuals closely, related individually. Site of, vernalization is apical meristem., 32. Assertion: The hierachy includes seven obligate, categories., Reason: Intermediate categories are used to, make taxonomic positions more informative., 37. Assertion: The nitrogen bases of the two chains, of DNA are held together by hydrogen bonds., Reason: Both chains of DNA are antiparallel., 21. During their migration, these cause, itense itching and swelling. Corymb inflorescence is found in, Cassia sp., A flower is regarded as complete if it has all, the four floral whorls, i. Assertion: IgM is a type of immunoglobulin which cannot cross the placenta. Reason: IgM is pentamer immunoglobulin, joined by J chain. e., calyx, corolla,, androecium and gynoecium. Assertion: Amoeba contains a contractile, vacuole., Reason: It helps in both digestion and, osmoregulation., 28. Thus, a, dosage compensation mechanism must be, present through which the effective dosage, of genes of the two sexes is made equal., This is achieved by inactivation of one X, chromosome in females which gets, condensed and become heteropyknotic., Since only one X chromosome is needed, for normal metabolism in cells of females,, in some cells, the other X chromosome has, the ability of being heterochromatic and, euchromatic in others. The green cotyledons, function as leaves of the seedling.
Spirogyra shows, haplontic life cycle and therefore, it shows, zygotic nucleus as well., (a) In some species of red algae, the cell walls, become hardened with calcium carbonate., These algae are hence, important for the, formation of coral reefs.