Clastic sedimentary rocks: The word clastic came from “clasts” which means grains. Mainly silicic rocks like sandstone, shale etc. fall under clastic rocks. Organic sedimentary rocks: Sedimentary rockswhich are formed due to biogenic activity/processes or form fromorganic matter are called organic sedimentary rocks.
The Correct answer is "We want to understand the many aspects of human health, physiology, and behavior that are influenced by genes"
The geneticists devote so many resources to studying genetics in humans because they have realized that there are several diseases or physical traits (which may be due to the mutant gene) which are controlled by genes. For example diabetes which was earlier only thought to be regulated by insulin is now known to be as a heretical disease. Also it has been found that genetic diseases that are not present in the parent suddenly appear in their children. This may be due to the presence of recessive traits associated with genes and are being transferred from the forefathers. Not only diseases the physiological characteristics such as skin colour, eye colour, height, hair colour etc are also due to the result of expression of traits carried by the genes.
In the current scenario the different lifestyle, food and harmful environment conditions also produces genetic variation. Thus it is very important for the geneticist to refer several knowledge resources to understand the expression of gene under varying condition and how it may impact the humans.
Explanation: Gametes are the cells used during sexual reproduction to produce a new individual organism or zygote. The male gamete, sperm, is a smaller, mobile cell that meets up with the much larger and less mobile female gamete, egg or ova. Both sperm and egg are only haploid cells. They only carry half of the chromosomes needed.
If you are talking about evolution, the two types of evidence is
1. fossil evidence
2. molecular evidence
Members of phylum Porifera are commonly known as spongs. They are generally marine and mostly asymmetrical animals. These are primitive multicellular animals and have cellular level of organization (lacks tissues). These Organisms (belonging to phylum Porifera) lacks most of the structures that are present in multicellular organisms like digestive system, respiratory system, Brain etc
Body of Spongs are made up of spicules or spongin fibers and these organism contain a water canal system which helps them in digestion, reproduction and catching their food in marine habitat.
