Answer:
Both biotic and abiotic factors affect the survival and reproductive success rate of fishes in an ecosystem.
The number of predators that a particular type of fish will have will influence the survival and reproductive rate of that fish. An increased number of predators will mean that the fishes will not be able to survive in that ecosystem and will be eaten up.
The number of preys will also affect the survival rate of fishes in an environment. The lesser the number of preys, the more the competition for food among species.
Abiotic factors like the concentration of salts in water will also influence the survival and reproduction of fishes. If a fish is not adapted to live in saline water conditions, then accumulation of salts in the ecosystem might destroy the whole fish species in that ecosystem.
Human activities, like the throwing of wastes into the aquatic ecosystem, drainage of fertilizers in the aquatic system can also destroy the survival and reproduction rate of a particular kind of aquatic animal species.
Explanation:
The influence DNA has upon the synthesis of lipids, carbohydrates and steroids can be summarized or stated by B. Proteins that DNA codes for catalyze the reactions that synthesize these compounds.
Immigration followed by competition
I hope this right, if its not, sorry =)
Answer:Enrico must multiply the distance of mars from sun (meters) with the 
to convert the distance in astronomical units.
Explanation:
1 astronomical unit = 
Let the distance between the sun and Mars be Y( meters)
Distance in AU= 
Enrico must multiply the distance of mars from sun (meters) with the to convert the distance in astronomical units.
The label A represents mitochondria.
The mitochondria is also called the powerhouse of the cell which converts glucose to energy rich molecules of ATP.
Label B represents nucleus.
Nucleus contains the genetic material or DNA, RNA , nucleolus, chromatin fibres and proteins. It contains the chromosomes which control the hereditary characteristics.
Label C represents lysosome.
Lysosomes contain digestive juices which breaks down large cell parts and large molecules and helps in intracellular digestion.
Label D represents rough endoplasmic reticulum having ribosomes.
The rough endoplasmic reticulum provides surface for protein synthesis. It is also used to transport cellular contents from one cell to another.
