Biology Questions

An organelle called Eyespot allows some protists to detect light. It allows the cells to sense light direction and intensity and respond to it by swimming either towards the light (positive phototaxis) or away from the light (negative phototaxis).

Eyespot is a photoreceptive organelle found in the flagellate or (motile) cells of green algae and other unicellular photosynthetic organisms such as euglenids.

Eyespot-mediated light perception helps the cells in finding an environment with optimal light conditions for photosynthesis. Eyespots are the simplest and most common "eyes" found in nature, composed of photoreceptors and areas of bright orange-red pigment granules.

a -  at the peak of changes in blood pressure indicates the systiolic pressure.

Prokaryotic and Eukaryotic cells do share a feature of DNA.

Both prokaryotic and eukaryotic cells have structures in common.

All cells have a plasma membrane, ribosomes, cytoplasm, and DNA.

Prokaryotic cells are primitive cells which have no true nucleus and membrane bound organelles, while Eukaryotic cells are cells that have true nucleus, membrane bound organelles and well defined structures and layouts.

The rungs or the sides of the DNA ladder is made of Deoxyribose, which is a pentose, and a phosphate group are the two molecules together form the two sides of the DNA i.e, A sugar (deoxyribose) and a phosphate.

Water is the important nutrient all organisms need. Humans has almost 60% of their body weight is water. Some organisms have 90% of their body weight is of water.