Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Formation of Primary Urine in Malpighian Tubules
The formation of primary urine in malpighian tubules is due to secretion and not due to ultrafiltration. The cells of the malpighian tubules actively transport potassium from the haemolymph and concentrate it in the lumen. This results in the passive osmotic entry of water followed by the diffusion of other low molecular weight substances like salts, sugar, and uric acid. Figure will help you in understanding this phenomena. The rate of urine formation in insects is proportional to the concentration of K+ in the haemolymph. Thus, active transport of K+ is primarily responsible for generating urine flow in the excretory organs of insects.
Figure: Functions of Malpighian Tubules of Insects
As the potassium-rich isosmotic tubular fluid moves towards the gut, there is secretion of molecules like uric acid and reabsorption of sugars and ions. However, major modification in the composition of the fluid occurs in the hind gut, particularly the rectum, where there is extensive reabsorption of water and physiologically important solutes like K+. Uric acid, which enters the hind gut as water soluble potassium urate, gets precipitated facilitating further withdrawal of water. Insects that live on liquid or wet food excrete large amounts of hypoosmotic liquid urine. On the other hand, insects that live on dry food produce extremely dry excreta. To facilitate water reabsorption, the rectum in terrestrial insects show modifications referred to as rectal glands or rectal pads.
What is the excitation threshold of a neuron? How does this threshold relate to the "all-or-nothing" rule of the neural transmission? The excitation threshold of a neuron is th
Q. What is thyroid disease? Thyroid disease: Thyroid disease is associated with angina. Anginas pectoris presents itself in the form of speific symptoms which tend to re- oc
a) What new combinations of characteristics might arise in the offspring when a tall plant with white flowers is crossed with a dwarf plant (of the similar species) with red flower
ENDOPLASMIC RETICULUM (ER) Eucaryotic celIs have two major compartments- nucleus and cytoplasm. Cytoplasm was known to have no structure until the discovery of electron micrsscop
Bone Modeling It is a surface-specific activity (apposition or resorption) that produces a net change in the size and/or shape of a bone after initial bone formation in the emb
Name the Foods to avoid in soft diet include: Fried foods and nuts, rich pastries and desserts, Raw vegetables, Heavily spiced foods, Gas-forming vegetables, S
Features of Amphibian Gastrulation Major features of amphibian gastrulation are: Ectoderm surrounds the embryo by Epiboly. Gastrulation is initiated by a limited i
Spermiogenesis - Spermatogenesis At the end of the meiosis the spermatids appear as simple spherical cells with a centrally located nucleus. Their differentiation into sperm r
Complete Metamorphosis In all Endopterygota insects, where wings and other structures develop internally, (in invaginate imaginal epidermal pockets) such as beetles, wasps, b
The cystic fibrosis allele occurs in European populations with q=0.02, what fraction of this population can be expected to have cystic fibrosis?
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd