Which of the following tissues provide maximum mechanical support to plant organs?
Sclerenchyma
Collenchyma
Parenchyma
Aerenchyma
B.
Collenchyma
Collenchyma is responsible for performing photosynthesis due to the presence of chloroplast and aerenchyma is responsible for allowing exchange of gases between the shoot and the root.
Sclerenchyma are dead mechanical tissue whose cells are long or short, narrow, thick walled and lignified. It acts as a versatile mechanical tissue that provides maximum mechanical strength to the plant. While, the other tissue such as parenchyma helps in storage of food and water and is involved in activities like photosynthesis, respiration, etc.
The crystal of lead zirconate is a key component of
sonography
electrocardiography
electroencephalography
magnetoencephalography
Assertion : Leaf butterfly and stick insect show mimicry to dodge their enemies.
Reason : Mimicry is a method to acquire body colour blending with the surroundings.
If both Assertion and Reason are true and the reason is the correct explanation of the assertion
If both Assertion and Reason are true but the reason is not the correct explanation of the assertion
If Assertion is true statement but Reason is false
If both Assertion and Reason are false statements
Lucocytes (WBCs) are considered as true cells because
they possess nucleus
they do not contain haemoglobin
they show great power of movement
they are responsible forphagocytic activity
The function of microvilli is :
cellular movement
specialized uptake of macro molecules
increase in surface area for absorption
extensive movement of substances over cell surface
Inner surface of the bronchi, bronchioles and fallopian tubes are lined by
cubical epithelium
columnar epithelium
squamous epithelium
ciliated epithelium
What external changes are visible after the last moult of a cockroach nymph?
Mandibles become harder
Anal cerci develop
Both fore wings and hind wings develop
Labium develops
