Biology 12th Class Biology

Chapter 16 Support and Movement – FSc Biology Notes Part 2

Chapter No 16
Support and Movement – FSc Biology Notes Part 2

Short questions Support and Movement

(i) What is the cause of cramps?
Answer. The cause our low blood sugar level, electrolyte depletion, dehydration irritability of spinal cord and neurone.

(ii) What is the diference between tetanus and muscle tetany?
Answer. Tetanus is a disease caused by an aerobic bacterium result in painful spasm of some skeletal muscles. While muscle tetany is a disease caused by low calcium in blood which affects neurones.

(iii) What is a ligament?
Answer. Ligaments are modification of fibrous joints. Which joins bone with bone.

(iv) What is “nutation”?
Answer. The growing tip of young stem moves in zigzag fashion due to alternate changes in growth on opposite side of the apex. This model of growth is called “nutation”.

(v) How many ribs do not attach with the sternum?
Answer. Two ribs do not attached with the sternum.
(vi) How is rickets produced?
Answer. Rickets are produced due to deficiency of calcium in diet for vitamin deficiency.

(vii) What is the cause of tetanus?
Answer. The cause of tetanus is is an aerobic bacterium clostridium tetani.

(viii) How is muscle fatigue produced?
Answer. Muscle fatigue is produced due to deficit of ATP.

(ix) Distinguish between the following.
(a) Axial skeleton and appendicular skeleton. (b) Phototactic and chemotactic stimulus. (c) Osteocytes and osteoblast. (d) Brachialis and brachioradialis. (e) Origin and insertion of muscles. (f) Bone and cartilage. (g) Troponin and tropomyosin.
Answer. (a) Axial Skeleton and appendicular skeleton

The axial skeleton consists of skull vertebrae and ribs sternum. Appendicular skeleton consists of pectoral girdle and appendages, pelvic girdle and appendage.

(b) Phototactic and Chemotactic Stimulus

Phototactic movement

The stimulus in this type of movement is light. The movement maybe towards the source of light or away from the source of light. The best example of positive tactic movement is passive movement of chloroplast due to cyclosis. This movement helps to chloroplast to absorb maximum light for O2 fixation. The light intensity and direction both affect the intracellular distribution of chloroplast.

Chemotactic movement

This type of movement take place when the simile are chemicals. Such type of movement is found in sperms of liverworts mosses, ferns towards archegonia in response to stimulus of nucleic acid released by ovum.

(c) Osteocytes and Osteoblast
Bone is a dynamic, living tissue that is constantly being reconstructed throughout the life of individual. New borne infants formed by self all osteoblast. Other than this the mature bone cells are called osteocyte and bone-dissolving cells are osteoclasts.

(d) Brachilalis and brachioradialis
The brachilalis is inserted in ulna while bracheoradilus is interested in certain radius.

(e) Origin and Insertion of muscles

(I) Origin
One end of the muscle is usually attached to more or less stationary base called origin.

(ii) Insertion
It is the end of muscle that moves the bone.

(f) Bone and Cartilage
(I) Bone is a special form of connective tissue in which collagen fibres are coated with calcium phosphate salt. It is a rigid structure but it never break.
(ii) Cartilage is a specialised connective tissue in which collagen matrix between cell is formed at positive mechanical stress.

(g) Troponin and tropomyosin
Twisting around the acting chain are the strands of protein called tropomyosin. The other protein in thin filament is tropin which is actually three polypeptide complex.

Extensive questions.
(i) What are the disadvantages of exoskeleton? Support and Movement

Answer. Exoskeletons are good due to the fact they are able to defend bugs and arthropods from their surroundings. They act form of like an armor around the body, and save you fungi, bacteria, and big predators from getting easy get admission to to the smooth insides. additionally they prevent loss of warmth and moisture from the body better than skin, because of their pressure and impenetrability. here is a have a look at at the precise defensive function of the exoskeletal wings of beetles in protecting them from getting eaten by way of spiders: beetles whose wing coverings were eliminated were notably much more likely to be eaten through a spider. purposeful fee of elytra beneath numerous stresses inside the pink flour beetle, Tribolium castaneum
Exoskeletons are not super if an animal is huge. for example, by way of tarantula has a overweight belly. The exoskeleton surrounding it’s far as thick because the exoskeleton at the relaxation of its frame; if my tarantula falls it’s rather possibly that her bottom will burst from the surprising pressure. Exoskeletons can’t resist as a whole lot surprise as skin. in addition they heal slower, on occasion never: if a tarantula’s exoskeleton is fissured, the exoskeleton will by no means restore itself, and the spider will prevent bleeding out handiest through forming a clot with its haemolymph (tarantula “blood.”) The handiest way to fully restore the exoskeleton is to shed the old one; new exoskeletons will steadily reduce damage, until a fully-regenerated organism comes out. This relies upon at the intensity of damage, how plenty a given wound penetrates into the still-forming future exoskeletons— at least for tarantulas. And on account that adults can only shed their skins every 2+ years, this means they can spend a whole lot of time with a water-soluble clot being the simplest issue maintaining them from bleeding out.
The final downside of exoskeletons that i can think of is the mandatory duration of helplessness in between sheddings. After ecdysis (the shedding of the exoskeleton), an organism have to await its new skeleton to harden, a period that ranges from hours (for cicadas) to numerous days (tarantulas). at this time the organism is largely boneless and ought to be sure to stay in a safe, static surroundings, due to the fact moisture and temperature changes can kill the organism an awful lot quicker. also, any fungal spores, micro organism, or mites can easily predate the organism and kill it. If the organism attempts to consume before its exoskeleton has hardened, it is able to bend its claws and fangs out of form and render itself unable to eat in any respect. Organisms with bones only have this kind of prone duration without delay after start; when one of our bones breaks, it’s fantastically irritating, however it’s best one a part of the body this is rendered so vulnerable.

(ii) What is the sliding ilament model? What does it explain?
Answer. Sliding Filament model of Muscle Contraction
The mechanism of muscle contraction is explained with the aid of sliding filament model. The arrangement of actin and myosin myofilament within a sarcomere is crucial within the mechanism of muscle contraction.
Actin: An actin myofilament is made from actin molecule, tropomyosin and troponin complex. Troponin consists of three sub-gadgets (troponin I, T and C). Tropomyosin shape helical strand that are wrapped round actin molecule longitudinally in thin twisted stranded form.
Myosin: A myosin filament includes a long rod-formed tail known as myosin rod and globular intertwined myosin head. The globular head seem at c programming language along the myosin myofilament.

(iii) Describe a hinge joint and explain how it is moved by antagonistic muscle.
Answer. A Hinge Joint
muscle tissues will contract and lighten up but they cannot stretch themselves, so they have to be stretched via the contraction of their opposed partners. All muscle tissues paintings in adverse pairs.
Use the animation on top of to see however the striated muscle and striated muscle work put together to create the ginglymoid joint flow. Hover over a muscle or bone to see its decision. click on a muscle to examine its name and what happens once it contracts click on a bone to see its commonplace name.
The elbow may be a hinge joint; it will open and shut sort of a door. Biologists use the word “amplify” to mean straighten the joint and therefore the phrase “flex” to intend bend the joint. The striated muscle is AN striated muscle because it extends the elbow. The striated muscle may be a skeletal muscle because it flexes the elbow.

Leave a Reply

Your email address will not be published. Required fields are marked *