Answer:
8%
Explanation:
Given that,
Mass of solute = 8 g
Mass of soultion, (mass of alloy) = 100 g
We need to find the percent by mass of 8.0g copper is added to enough zinc to produce 100g an alloy. It can be calculated by the formula as follows :
So, the percent by mass is 8%.
<u>Answer:</u>
Limited resources contribute to evolutionary change in animals by increasing Intra-specific competition.
<u>Explanation:</u>
- Intra-specific competition means competition among the members of same species.
- Individual of same species have same ecological niche i.e. how an organism is related with biotic and abiotic aspect of environment.
- So they require same resources of their survival. When population of any species increases then there is high chance of intra-specific competition because of limited resources.
- Intra-specific competition also determine the population size of species. For example, competition among shark rodents.
A. direct B. indirect C. direct D. indirect
Competition occurs by direct and indirect means. Organisms interact directly by fighting (aggression) for scarce resources. Two eagles fighting over the salmon carcass and two colonies of ant clashing over a wasp are samples of aggression (direct competition)
Indirect competition happens when there is a common or limited <span>supply of at least one resource (food, water, and territory). </span>Use of this resource lessens and later depletes the amount available to others, or they compete for space.<span> Gray foxes preying on penguins and squirrels relying on nuts for food are samples of indirect competition.</span>
<u>Phenylketonuria</u>
Explanation:
Phenylketonuria (PKU) is a type of a rare inherited metabolic disorder.
Etiology: PKU results from excessive accumulation of the amino acid phenylalanine in the body. Normally, phenylalanine will be converted to tyrosine (forms neurotransmitters) by the action of the enzyme phenylalanine hydroxylase.
Among people with PKU, a defect in the PAH gene which codes to synthesize this enzyme occurs which leads to the absence of this enzyme. So the phenylalanine which is normally present in dietary protein is not metabolized and gets accumulated. This gene is inherited by the child only if both the parents are with the defective PAH gene.
Symptoms: Stunted growth, behaviroral disturbances, learning difficulties, seizures, tremors etc.
Treatment: Basic treatment is to follow a diet which limits dietary sources of phenylalanine. High protein foods like meat, egg should be avoided. Children can be given PKU formula to supplement their nutritional needs.
Answer:
c. Only one of the statements is true
Explanation:
Quaternary structure, the highest level of protein organization in which association of several protein chains are closely arranged. The protein subunits are attached together by van der Waals forces and hydrogen bonds between nonpolar side chains. it is present in all the proteins which have 80 or more amino acids are present.
Collagen, is most abundant protein in the animal kingdom. It is insoluble fibrous protein present in the extracellular matrix and in connective tissue.
A protein chain has directionality consist of a free amino group at one end, and a free carboxyl group on other end.
Hence, only (2) statement is true the correct option is c.
