The structure being described is the tricuspid valve.The right atrium is one of the two atria of the heart which function by receiving blood entering the heart, it is located to the right of the left atrium and superior to the much larger and more muscular right ventricle. Between the right atrium and right ventricle is a one way valve known as the tricuspid valve.
The lower limb bones are attached to the axial skeleton by a ring of bones called the pelvic girdle. The pelvic girdle consists of the right and left hip bones.
The bones of the head and trunk of the vertebrate form the axial skeleton.
The membranes that surround and protect the brain and spinal cord are called meninges.
Answer:
Electron
Explanation:
The electron is subatomic particle that revolve around outside the nucleus and has negligible mass. It has a negative charge.
Symbol= e-
Mass= 9.10938356×10-31 Kg
It was discovered by j. j. Thomson in 1897 during the study of cathode ray properties.
He constructed the glass tube and create vacuum in it. He applied electric current between electrodes. He noticed that a ray of particles coming from cathode to wards positively charged anode. This ray was cathode ray.
Properties of cathode ray:
The ray is travel in straight line.
The cathode ray is independent of composition of cathode.
When electric field is applied cathode ray is deflected towards the positively charged plate.
Hence it was consist of negatively charged particles.
While neutron and proton are present inside the nucleus. Proton has positive charge while neutron is electrically neutral. Proton is discovered by Rutherford while neutron is discovered by James Chadwick in 1932.
Symbol of proton= P+
Symbol of neutron= n0
Mass of proton=1.672623×10-27 Kg
Mass of neutron=1.674929×10-27 Kg
Answer:
d. smooth endoplasmic reticulum
Explanation:
Organelles are structures found in inside the cell which carries out a specific function. Types of organelles include endoplasmic reticulum, Golgi body, ribosomes, nucleus etc. The function in the question is protein synthesis.
Ribosomes are the sites of protein synthesis in the cell of living organisms.
- The nucleus is involved in the synthesis of protein because it directs all the cellular processes in a cell including protein synthesis.
- Rough endoplasmic reticulum (RER) is a type of endoplasmic reticulum whose surface is attached to by ribosomes, hence, giving it its rough surface. Since ribosomes (organelle for protein synthesis) are attached to the RER, the RER are involved in protein synthesis.
- Golgi bodies are organelles that functions to package, process and sorted the proteins produced in the ribosomes.
- The smooth endoplasmic reticulum (SER) are NOT involved in the synthesis of protein because they have no ribosomes attached to their surface. Instead, they are involved in lipid synthesis.
