Answer:
Energy added to cold water, E1
E1 = m•Cp•ΔT = 6 x 4.187x(42-20) = 6x4.187x22
Energy lost by hot water, E2:
E2 = X(CpΔT) = X x 4.187 x (75-42) =X x 4.187 x 33
So, since E1 = E2
6x4.187x22 = X x 4.187 x 33
X = 6x22/33 = 4.0kg
So the mass of the hot water added to the 6kg of cold water is 4.0kg
 
        
             
        
        
        
<span>Only a single amino acid could change, because the reading frame is unaffected</span>
 
        
             
        
        
        
Answer:
Plant cells have a cell wall, a large central vacuole, and chloroplasts, but a animal cell does not have those things.
Nucleus; contains DNA
Lysosome; breaks down nutrients and wastes
Vacuole; storage
Centrosome; has a role in Mitosis to seperate chromosomes
Chloroplast; photosynthesis
Endoplastic Reticulum; transport nutrients within the cell
Ribosome; protein synthesis
Mitochondria; breaks down glucose into ATP energy
Cell wall; a rigid membrane found in plants and some bacteria
Golgi apparatus; packages proteins made, exocytosis
Cell membrane; a flexible mebrane around eukaryotic cells
Hope this helped 
Brainliest please; i need it to reach the next rank
Explanation:
 
        
             
        
        
        
Answer:
A) A tentative statement used to guide a scientific investigation is called scientific hypothesis.
As hypothesis is a proposed details of a phenomena, it can guide us in one way or another to carry out the scientific investigation.
B) Makes prediction about future events is scientific hypothesis.
Scientific hypothesis bases on the observation made predicts about future events, which could be either true or false.
C) Can be tested many independent researches is a scientific theory. 
A scientific theory is developed when it has been passed through many researches and had gained acceptance too.
D) Both Scientific theory and hypothesis are based on the observations of the natural phenomena. 
Firstly, an observation is made based on natural phenomena, which leads to questions, then research or study is carried out to answer these questions leading to the formation of a hypothesis which upon successful  testing forms a theory.
E) Scientific theory is a well-established highly reliable explanation. 
It a highly sustained explanation based on facts of nature, that are confirmed via a lot of experiments.