Biology - Study Mode
[#141] The skeleton secreting cells in poriferans are known as
Correct Answer
(A) Scleroblasts
Explanation
Solution: The spicules are secreted by specialized mesenchyme cells known as scleroblasts. Scleroblast secreting a calcareous spicule is called calcoblast while that producing a siliceous spicule is called silicoblast.
[#142] Which one of the following phylum is characterised by absence of true coelom?
Correct Answer
(A) Nematoda
Explanation
Solution: Nematodais characterised by absence of true coelom.
[#143] Out of 900 reported species of living gymnosperms, conifers are represented by about 500 species, About 2,50,000 species of angiosperms (flowering plants) have also been reported in the world. The vast and dominant woodlands in Europe, Asia, North America and mountains such as Himalayas are wooded with
Correct Answer
(C) only conifers
Explanation
Solution: Out of 900 reported species of living gymnosperms, conifers are represented by about 500 species, About 2,50,000 species of angiosperms (flowering plants) have also been reported in the world. The vast and dominant woodlands in Europe, Asia, North America and mountains such as Himalayas are wooded with only conifers.
[#144] One of the following is not a function of bones.
Correct Answer
(C) Secretion of hormones for calcium regulation in blood and bones
Explanation
Solution: Secretion of hormones for calcium regulation in blood and bones is not a function of a bone.
[#145] Plants absorb most part of water needed by them through their
Correct Answer
(C) root hairs
Explanation
Solution: Root hair cells are specialized epidermal cells that greatly increase the surface area of roots. The function of root hairs is to collect water and mineral nutrients present in the soil and take this solution up through the roots to the rest of the plant.