Answer:
D. Molecules called pumps function to control active transport.
Explanation:
Active transport is one of the two types of transport (the other being passive transport). It is the type of transport in which substances move against their concentration gradient i.e. from a lower concentration to a higher concentration. Hence, due to this, energy input in form of ATP is required by the cell.
However, the process of active transport makes use of certain molecules called PUMPS to control it. The pumps moves ions/molecules against their concentration gradient. An example is the sodium-pottasium pump which moves sodium ions from a region of low conc. to a region of high conc.
Answer:
Double fertilization
Explanation:
The phenomenon of double fertilization is unique to flowering plants (i.e., angiosperms). Each pollen grain produces two male gametes (sperm cells), one of which fertilizes the egg to form the zygote, whereas the other sperm fuses with polar nuclei in the female gametophyte in order to form a triploid cell (3n) called endosperm. Subsequently, this endosperm will support embryonic growth by supplying storage nutrients and by serving as a mechanical barrier during seed development and germination.
The brain, heart and the skeleton are the integral parts of the nervous system, circulatory system and the skeletal system respectively. The nervous system is made of the brain and the spinal cord with neurons as the structural and functional units of it. The circulatory system is made up of the heart and its blood vessels. The skeletal system is made up of the bones and cartilages making the skeleton of the body.
The brain regulates the heart beat and the blood pressure. The heart nourishes the brain with oxygen and nutrients by pumping blood. The bone cells are nourished by the blood pumped by the heart. The bone marrow of the skeleton produces the new red blood cells which enter the blood circulatory system. Also the the ribs and the breast bone of the skeleton protects the heart, the cranium of the skeleton prtects the brain. The bones also provide calcium which is necessory for the functioning of the nervous system. The brain controls the skeletal movements of the body. The cerebellum of the brain controls the voluntary skeletal movements and the medulla controls the involuntary skeletal movements of the body. The blood brain barrier formed by the endothelial cells of the capillary walls located in the brain seperates the circulating blood from the brain and the extraclellular fluid in the central nervous system and acts as a selective semipermeable border.
Answer:
Allows farmers to grow plants using very little soil
Explanation:
Fertilizer helps us to return the nutrients to the soil for new or current plants to grow. These nutrients were spent by the plants that were there or the soil was not that rich with nutrients, to begin with. It will not replace soil and growing plants without soil is called hydroponics. Fertilizer is very useful in agriculture currently and most likely will continue to be a good way to grow plants for a while.
Answer:Most of the space inside the atom is empty because most of the α-particles passed through the gold foil without getting deflected.
Explanation:
