The teratogens can be defined as any physical, chemical, or infections agents that have the ability to penetrate the protective layers of the embryo, and affect its viability. The overall development and the development of the different organ systems might be affected because of these teratogens. When the embryo is exposed to the teratogens after the organogenesis is complete, it is most likely that the fetus will suffer from the stunted growth. When the organogenesis is complete, the organs are already formed, and hence, no severe damage can occur to them. Down's syndrome will result if the chromosomal abnormality occur in the fetus, which is not likely after the organogenesis is already complete. Any kind of severe anatomical defects are also least likely after organogenesis is completed. Therefore, the chances of having stunted growth are high.
Answer:
No one can see in total darkness. Fortunately, there’s almost always some light available. Even if it’s only dim starlight, that’s enough for your eyes to detect. What’s truly amazing is how little light is required for you to see.
Human eyes have two main features that help us see better in low light: the pupil’s ability to change size, and the eye’s two types of light-sensing cells.
Opening up to let in more light
Your pupils are the black areas at the front of your eyes that let light enter. They look black because the light that reaches them is absorbed inside the eyeball. It’s then converted by your brain into your perceptions of the world.
You’ve probably noticed that pupils can change size in response to light. Outside on a bright sunny day, your pupils become very small. This lets less light into the eye since there’s plenty available
Answer:
Biologists measure the number of trophic levels in an ecosystem so as to check its stability and health.
Explanation:
Trophic levels are the feeding position in a food chain such as primary producers, consumers, etc. They are positions that an organisms occupies in a food chain (series of steps in which organisms transfer energy by eating or being eaten);- what it eats and what eats it.
Theoretically there is no any limit to the number of trophic levels in a food chain or number of organisms that live on each level.
