Biology
State the main function of the following:
(i) Chordae tendinae
(ii) Lymphocytes
(iii) Seminiferous tubule
(iv) Thylakoids
(v) Beta cells of pancreas
Answer
(i) Chordae tendineae play a vital role in holding the atrioventricular valves in place while the heart is pumping blood.
(ii) Lymphocytes produce antibodies which kill or neutralise the germs or the poisons from them.
(iii) The Seminiferous tubules produce sperms by the process called spermatogenesis.
(iv) The thylakoid membranes of a chloroplast are the site of light reactions of photosynthesis as the pigment chlorophyll is contained in the walls of thylakoids.
(v) Secrete insulin that helps to lower the level of glucose in blood.
Related Questions
Choose the correct answer from the four options given below each statement:
A reflex arc in man is best described as movement of stimuli from :
- Receptor cell, sensory neuron, relaying neuron, effector muscles.
- Receptor cell, efferent nerve, relaying neuron, muscles of the body
- Receptor cell, spinal cord, motor neuron, relaying neuron.
- Receptor cell, synapse, motor neuron, relaying neuron.
Choose the correct answer from the four options given below each statement:
NADP is expanded as :
- Nicotinamide, adenosine dinucleostide phosphate
- Nicotinamide, adenine dinucleotide phosphate
- Nicotinamide, adenine dinucleous phosphate
- Nicotinamide, adenosine dinucleous phosphate
Give the exact location of the:
(i) Lenticels
(ii) Prostate gland
(iii) Thyroid gland
(iv) Centrosome
(v) Mitral valve
Given below are sets of five terms each. In each case rewrite the terms in logical sequence as directed at the end of each statement. An example has been done for you:
Example : Cortical cells, Root hair, xylem, Soil water, endodermis (absorption of water by the plants)
Answer : Soil water, Root hair, cortical cells, endodermis, xylem.(i) Active immunity, Antigen, Antibody, Bacteria, Lymphocytes (defence mechanism of the body).
(ii) Implantation, Parturition, Ovulation, Gestation, Fertilisation (stages leading to formation of foetus and birth).
(iii) Oval window, Tympanum, Cochlea, Auditory canal, Ear ossicles (path through which a vibration of sound is transferred in the human ear).
(iv) Karyokinesis, S-phase, Cytokinesis, G1-phase, G2-phase (cell cycle).
(v) Renal vein, Renal artery, Afferent arteriole, Efferent arteriole, Glomerulus (pathway of blood through glomerulus).