In certain flowering plants, the flower contain more stamen than pistil to increase chances of pollination.
The stamen is the male reproductive part of a flower and the pistil is the female reproductive part of the flower.
More stamen means more pollen. By producing more stamen and therefore more pollen, the chances of pollen coming into contact with the pistil are much higher especially since pollination depends on either wind or insects.
However, not all flowering plants have this arrangement.
Answer:
EDTA is a chelating agent used to preserve samples for DNA extraction and as an anticoagulant
Explanation:
Ethylenediaminetetraacetic acid (EDTA) is a well-known chelating agent that binds metal ions (iron and calcium ions). In police cases, EDTA can be used for DNA extraction since this agent chelates metal ions in DNase enzymes which are contained in the samples, thereby reducing their activity and preserving DNA samples for a long time. Moreover, EDTA is also used as an anticoagulant for blood cells, which allows preserving the cellular components and the morphology of blood samples.
Answer:
The correct answer is: Yes, this is an example of Reproductive Isolation.
Explanation:
- Reproductive Isolation can be defined as the mechanism adopted by different species during the course of their evolution, due to which the individuals belonging to different species are incapable of mating with each other and producing viable offspring.
- The given question is an example of Mechanical, Pre-zygotic Reproductive Isolation.
- Prezygotic Isolation refers to the mechanism adopted by individuals of different species during the course of evolution such that successful fertilisation of gametes from individuals of different species never occur, hence a viable zygote is never formed.
- Mechanical Isolation refers to the mechanism adopted by individuals of different species during the course of evolution such that their reproductive organs or the organs that assist in the process of reproduction are incompatible to each other. Hence, the gametes of each species are unable to come in vicinity of each other.
- Here, the pollen grain from the flower of one species of juniper is unable to form the pollen tube when its sits on the stigma of the flower of another species of juniper. This is an example of Mechanical Isolation.
The swallowing mechanism consists of three stages, beginning with the oral phase that begins in the mouth. The second stage, called the pharyngeal phase, triggers the swallowing reflex that moves food through the throat, or pharynx. During the pharyngeal phase, the larynx closes and breathing stops while food begins to move through the throat to the esophagus. The closing of the larynx is accomplished by the epiglottis. During the third stage, food is moved down the esophagus to the stomach.
Answer:
Chemical nutrients and energy tend to flow in the same direction for most of an ecosystem. The big difference is that the chemical nutrients are ultimately recycled in the ecosystem while the energy is ultimately lost from the ecosystem to the universe at large. Energy in any ecosystem ultimately comes from the Sun.
