In a moss the sporophyte
is partially parasitic on the gametophyte
produces gametes that give rise to the gametophyte
arises from a spore produced from the gametophyte
arises from a spore produced from the gametophyte
People living at sea level have around 5 million RBC per cubic millimeter of their blood whereas those living at an altitude of 5400 metres have around 8 million. This is because at high altitude:
people get pollution-free air to breathe and more oxygen is available
atmospheric O2 level is less and hence more RBCs are needed to absorb the required amount of O2 to survive
there is more UV radiation which enhances RBC production
there is more UV radiation which enhances RBC production
A major breakthrough in the studies of cells came with the development of electron microscope. This is because
the resolution power of the electron microscope is much higher than that of the light microscope
the resolving power of the electron microscope is 200 – 350 nm as compared to 0.1 – 0.2 nm for the light microscope
electron beam can pass through thick materials, whereas light microscopy requires thin sections
electron beam can pass through thick materials, whereas light microscopy requires thin sections
Which one of the following is a matching set of a phylum and its three examples?
Cnidaria — Bonellia, Physalia, Aurelia
Platyhelminthes — Planaria, Schistosoma, Enterobius
Mollusca — Loligo, Teredo, Octopus
Mollusca — Loligo, Teredo, Octopus
Metameric segmentation is the characteristic of
Platyhelminthes and Arthropoda
Echinodermata and Annelida
Annelida and Arthropoda
Annelida and Arthropoda
What is common about Trypanosoma, Noctiluca, Monocystis and Giardia?
These are all unicellular protists
They have flagella
They produce spores
They produce spores
Which of the following statements regarding cilia is not correct?
The organized beating of cilia is controlled by fluxes of Ca2+ across the membrane
Cilia are hair-like cellular appendages
Microtubules of cilia are composed of tubulin
Microtubules of cilia are composed of tubulin
Which of the following environmental conditions are essential for optimum growth of Mucor on a piece of bread?
A. Temperature of about 25°C
B. Temperature of about 5°C
C. Relative humidity of about 5%
D. Relative humidity of about 95%
E. A shady place
F. A brightly illuminated place
Choose the answer from the following options
A, C and E only
A, D and E only
B, D and E only
B, D and E only
During photorespiration, the oxygen-consuming reaction(s) occur in
stroma of chloroplasts and mitochondria
stroma of chloroplasts and peroxisomes
grana of chloroplasts and peroxisomes
grana of chloroplasts and peroxisomes
Which one of the following not act as a neurotransmitter?
Acetylcholine
Epinephrine
Nor epinephrine
Nor epinephrine
D.
Nor epinephrine
Cortisone is a corticosteroid that is itself biologically inactive and is formed naturally in the adrenal gland (adrenal cortex) from the active hormone cortisol. Cortisol promotes the synthesis and storage of glucose and important in the normal response to stress, suppresses inflammation and regulates deposition of fat in body.
Acetylcholine is a neurotransmitter secreted from the nerve endings.
Epinephrine and nor-epinephrine are secreted from the medulla of adrenal gland and these also acts as neurotransmitter.