Answer:
Answer is E.
Explanation:
Generally, sphincter are circular or ring - shaped muscles, surrounding the natural opening in the body. They control the movement of substances by opening and closing through expansion and contraction.
There are many sphincter in the body, examples are
* Cardiac sphincter...found at the upper area or portion of the stomach.
* Pupilary sphincter..found in the iris of the eye.
* Glisson's sphincter...controlling the secretion of the gall bladder,pancrease and the liver.
Answer:
Cell organelle
Explanation:
The cell organelle is the small organ-like structure present inside the cell in the cytoplasm.
Different types of cell organelles are present in the cell which performs specific functions like of storage, of digestion of biomolecules like lysosomes, of protein synthesis and many others.
The organelles are usually enclosed by either a single phospholipid membrane like in lysosomes, Golgi apparatus or two lipid layers like in nucleus and chloroplast.
Thus, cell organelle is the correct answer.
Answer/Explanation:
Types of reproductive isolation include: temporal, ecological, mechanical, and behavioural.
A snail with a flat disc-like shell will not be able to mate with a snail having a conical shell - this is an example of mechanical isolation, where the animals are physically unable to mate due to incompatible body shapes and sizes.
The reproductive organs of male bush babies do not match with the reproductive organs of females of other bush baby species. - this is another example of mechanical isolation, as the sexual organs will physically not allow reproduction between these species
The mating call of a cricket is not recognized by a cricket of other species - this is an example of behavioural isolation, which results from incompatible mating rituals. I.e. the animals do not respond to each others mating behaviours
The signals sent by a male firefly are not recognized by the female firefly of other species. - this is also an example of behavioural isolation.
Temporal isolation is where species cannot interact because they do not have the same mating seasons or are not active at the same type of day. ?Ecological isolation occurs when two species do not come into physical contact to one another because they access different areas of the habitat. E.g. mating zones, food sources or nesting sites.
The first organisms to inhabit Earth were prokaryotes that
lived 3.5 billion years ago. prokaryotes are well organised, achieving all of an organism’s life functions
within a single cell. These were the precursors to eukaryotic cells
Answer:
The correct answer is option A, that is, cytochrome c oxidase.
Explanation:
A sequence of complexes, which conduct electrons from electron donors to electron acceptors through redox reactions, that is, both oxidation and reduction reactions taking place simultaneously is termed as the electron transport chain. This conduction of electrons is further combined with the mediation of protons across a membrane.
Four membrane-bound complexes are present within the mitochondria, of these in complex IV or cytochrome c oxidase, the withdrawal of 4 electrons takes place from 4 molecules of cytochrome c, and is mediated towards the molecular oxygen, which further gives rise to 2 molecules of water. During the process, 8 H+ are withdrawn from the mitochondrial matrix, which contributes to the proton gradient.
