In multicellular organisms there are millions of cells. Most of these cells are specialised to carry out a few functions. Each specialized function is taken up by a different group of cells or tissues. Since these cells of a tissue carry out only a particular function, they do it very efficiently. FRead more
In multicellular organisms there are millions of cells. Most of these cells are specialised to carry out a few functions. Each specialized function is taken up by a different group of cells or tissues. Since these cells of a tissue carry out only a particular function, they do it very efficiently. For example, in human beings, muscle cells contract and relax to cause movement, nerve cells carry messages and blood flows to transport oxygen, food, form ones and waste materials and so on. Likewise, in plants, vascular tissues (xylem, phloem) conduct water and food from one part of the plant to other parts. So, multicellular organisms show division of labour.
(a)They are undergoing divisions (by mitosis) and do not store food. (b) They have lignified walls and form bundles for mechanical function. (c) It has stone cells or sclereids. (d) Collenchyma provides them flexibility. (e) Sclerenchyma fibres are tightly packed.
(a)They are undergoing divisions (by mitosis) and do not store food.
(b) They have lignified walls and form bundles for mechanical function.
(c) It has stone cells or sclereids.
(d) Collenchyma provides them flexibility.
(e) Sclerenchyma fibres are tightly packed.
Water hyacinth (Eichornia crassipes) has spongy petioles which enclose a lot of makes the plant lighter than water so that it is able to float on surface of water.
Water hyacinth (Eichornia crassipes) has spongy petioles which enclose a lot of makes the plant lighter than water so that it is able to float on surface of water.
In animals, subcutaneous fat functions as an insulating layer that prevents heat loss from the body in cold environment. so animals in cold areas and fishes of cold 'water possess thicker layer of subcutaneous fat. Fat also functions as reserve food during periods of food scarcity.
In animals, subcutaneous fat functions as an insulating layer that prevents heat loss from the body in cold environment. so animals in cold areas and fishes of cold ‘water possess thicker layer of subcutaneous fat. Fat also functions as reserve food during periods of food scarcity.
Epidermis is the outer protective. Layer of plant body which does not allow the parasites to gain entry into plant's internal tissues due to (i) absence oi intercellular spaces; (ii) thick outer walls;(iii) deposition of cutin and wax in the cuticle covering the epidermis; (iv) silica and other depoRead more
Epidermis is the outer protective. Layer of plant body which does not allow the parasites to gain entry into plant’s internal tissues due to (i) absence oi intercellular spaces; (ii) thick outer walls;(iii) deposition of cutin and wax in the cuticle covering the epidermis; (iv) silica and other deposition.
Blood platelets are responsible for the release of thromboplastin necessary for blood clotting at the site of injury. In the absence of blood platelets, blood clotting will not occur after injury and bleeding will continue from the wound. This will finally cause the death of the injured person.
Blood platelets are responsible for the release of thromboplastin necessary for blood clotting at the site of injury. In the absence of blood platelets, blood clotting will not occur after injury and bleeding will continue from the wound. This will finally cause the death of the injured person.
Apical meristems are present at the tips of roots, shoots, branches and leaves. They form the growing parts of the roots and stems. If they are damaged or cut, the growth in length of that part will cease to occur.
Apical meristems are present at the tips of roots, shoots, branches and leaves. They form the growing parts of the roots and stems. If they are damaged or cut, the growth in length of that part will cease to occur.
Blood is considered as mobile connective tissue because, during circulation, it passes through all the organs of the body and in doing so, it connects different tissues and organs of the body.
Blood is considered as mobile connective tissue because, during circulation, it passes through all the organs of the body and in doing so, it connects different tissues and organs of the body.
What is the utility of tissues in multicellular organisms?
In multicellular organisms there are millions of cells. Most of these cells are specialised to carry out a few functions. Each specialized function is taken up by a different group of cells or tissues. Since these cells of a tissue carry out only a particular function, they do it very efficiently. FRead more
In multicellular organisms there are millions of cells. Most of these cells are specialised to carry out a few functions. Each specialized function is taken up by a different group of cells or tissues. Since these cells of a tissue carry out only a particular function, they do it very efficiently. For example, in human beings, muscle cells contract and relax to cause movement, nerve cells carry messages and blood flows to transport oxygen, food, form ones and waste materials and so on. Likewise, in plants, vascular tissues (xylem, phloem) conduct water and food from one part of the plant to other parts. So, multicellular organisms show division of labour.
See lessGive reasons for: (a) Meristematic cells have a prominent nucleus and dense cytoplasm but they lack vacuoles (b) Intercellular spaces are absent in sclerencymatous tissue (c) We get a crunchy and granular feeling when we chew pear fruit (d) Branches of a tree move and bend freely in high wind-velocity (e) It is difficult to pull out the husk of coconut.
(a)They are undergoing divisions (by mitosis) and do not store food. (b) They have lignified walls and form bundles for mechanical function. (c) It has stone cells or sclereids. (d) Collenchyma provides them flexibility. (e) Sclerenchyma fibres are tightly packed.
(a)They are undergoing divisions (by mitosis) and do not store food.
See less(b) They have lignified walls and form bundles for mechanical function.
(c) It has stone cells or sclereids.
(d) Collenchyma provides them flexibility.
(e) Sclerenchyma fibres are tightly packed.
Water hyacinth floats on water surface. Explain.
Water hyacinth (Eichornia crassipes) has spongy petioles which enclose a lot of makes the plant lighter than water so that it is able to float on surface of water.
Water hyacinth (Eichornia crassipes) has spongy petioles which enclose a lot of makes the plant lighter than water so that it is able to float on surface of water.
See lessFill in the blanks: Xylem transports ……… and…….from soil.
Xylem transports Water and minerals from soil.
Xylem transports Water and minerals from soil.
See lessAnimals of colder region and fishes of cold water have thicker layer of subcutaneous fat. Describe why?
In animals, subcutaneous fat functions as an insulating layer that prevents heat loss from the body in cold environment. so animals in cold areas and fishes of cold 'water possess thicker layer of subcutaneous fat. Fat also functions as reserve food during periods of food scarcity.
In animals, subcutaneous fat functions as an insulating layer that prevents heat loss from the body in cold environment. so animals in cold areas and fishes of cold ‘water possess thicker layer of subcutaneous fat. Fat also functions as reserve food during periods of food scarcity.
See lessWhich structure protects the plant body against the invasion of parasites?
Epidermis is the outer protective. Layer of plant body which does not allow the parasites to gain entry into plant's internal tissues due to (i) absence oi intercellular spaces; (ii) thick outer walls;(iii) deposition of cutin and wax in the cuticle covering the epidermis; (iv) silica and other depoRead more
Epidermis is the outer protective. Layer of plant body which does not allow the parasites to gain entry into plant’s internal tissues due to (i) absence oi intercellular spaces; (ii) thick outer walls;(iii) deposition of cutin and wax in the cuticle covering the epidermis; (iv) silica and other deposition.
See lesswhat will happen if all blood platerets are removed from blood?
Blood platelets are responsible for the release of thromboplastin necessary for blood clotting at the site of injury. In the absence of blood platelets, blood clotting will not occur after injury and bleeding will continue from the wound. This will finally cause the death of the injured person.
Blood platelets are responsible for the release of thromboplastin necessary for blood clotting at the site of injury. In the absence of blood platelets, blood clotting will not occur after injury and bleeding will continue from the wound. This will finally cause the death of the injured person.
See lessWhat will happen if bone marrow is destroyed.
Bone marrow produces blood cells. If bone marrow is destroyed, white blood cells (WBCs), red blood corpuscles (RBCs) and platelets will not be formed.
Bone marrow produces blood cells. If bone marrow is destroyed, white blood cells (WBCs), red blood corpuscles (RBCs) and platelets will not be formed.
See lessWhat will happen if apical meristem is damaged or cut?
Apical meristems are present at the tips of roots, shoots, branches and leaves. They form the growing parts of the roots and stems. If they are damaged or cut, the growth in length of that part will cease to occur.
Apical meristems are present at the tips of roots, shoots, branches and leaves. They form the growing parts of the roots and stems. If they are damaged or cut, the growth in length of that part will cease to occur.
See lessWhy is blood considered to be connective tissue?
Blood is considered as mobile connective tissue because, during circulation, it passes through all the organs of the body and in doing so, it connects different tissues and organs of the body.
Blood is considered as mobile connective tissue because, during circulation, it passes through all the organs of the body and in doing so, it connects different tissues and organs of the body.
See less