Theory can be changed based on new research but law is backed up with immense info and is has not been broken once
Antarctic fish species requires an adaptation to cold environment. Living at cold temperature environment would demand certain biological responses such as cutaneous respiration, enlarged blood vessels, and producing greater amounts of fat. Most of these fat are composed of higher phospolipid levels which are primarily due to phosphatidylethanolamine. This phospolipid is responsible for destabilizing cell membranes and make it more fluid thereby allowing unrestricted blood flow. The fatty acid composition of the membrane lipid is important for membrane fluidity, this is mainly attributed to unsaturated fatty acids which are responsible for decreasing the order of membrane lipids thereby decreasing viscosity. At extremely low temperatures, organisms with low concentration of unsaturated fatty acids would freeze cell membranes. That's why antarctic fishes have higher levels of unsaturated fatty acids.
During a solar eclipse, when the Moon's shadow falls on the Earth, we stand in the shadow rather than looking at it. Observers standing in the umbra see a total eclipse of the Sun, while observers under the penumbra see a partial eclipse.
Answer:
Answer is option A.
Orchid bees are to Brazil nut trees as breezes are to pine trees.
Explanation:
In Brazil nut trees, the female orchid bees act as pollinators that help in pollination. In pine trees, wind or breeze helps in pollination.
Pine trees are gymnosperms and so they do not have flowers to attract pollinators like bees or butterflies or birds. They are wind-pollinated. Pine trees are monoecious i.e., both male and female reproductive structures (pine cones) are present on the same tree.
The male cones (catkins) produce pollen grains that are lightweight, less sticky and have air bladders or small wing-like structures. As a result of these features, the pollen grains can be easily carried and dispersed by the breeze. In order to prevent self pollination (pollen falling on the female cones of the same tree), the male cones are normally located on the lower branches of the pine tree.
The female cones are located on the upper branches of the tree and the center of the cone contains eggs or ovules. The pollen grains that are carried by the wind, fall on the female cone of another pine tree. Each pollen grain grows a pollen tube into the center of the cone and the nucleus cell of the pollen travels through the tube and reaches the egg, where it combines with the egg to form an embryo. The embryo eventually grows into a seed. The seeds of pine trees are then dispersed by wind or animals such as squirrels.
