The difference between an artery and a vein is that arteries are larger, more muscular and more elastic than veins; they carry blood that is under pressure from having been pumped out of the heart; veins are under much less pressure, so they are not as strong
Answer:
3 Pollen tube forms and grows through the style
5 Sperm fertilizes the egg
1 Pollen is released from the anther
4 The pollen tube reaches the ovule within the ovary
2 Pollen sticks to the stigma
Explanation:
The process of double fertilization entails the fertilization of the egg by one sperm and that of two polar nuclei to produce the triploid endosperm tissue that nourishes embryo.
* The image describes the process in detail.
Answer:
A. maintenance of axons is not a cellular activity associated with microtubules.
Explanation:
Microtubules are hollow, bead-like, tiny tubular structure that helps cells maintain its shapes. Together with microfilaments and intermediate filaments, they form part of the cell's cytoskeleton. Microtubules also contributes to the cell movement or cytokinesis that includes muscle contractions in muscle cells. Microtubules also replicated chromosomes to opposite ends of a cell during cell division. Microtubules also contribute to the parts of the cell that help it move and are structural elements of cilia, centrioles and flagella. A bundle of microtubules makes up an axonemal structure of cilia and flagella.
Ecological balance always require that there must be more producers than the number of consumer. When the equation for ecological balance will be reverse there will be ecological imbalance which is called the disturbances. This will later on cause the scarcity of resource and extinction of one species.
Most likely D, because pesticides are poisonous to surrounding life.
