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Answer:</h2>
The scientist started to study relationships among various groups of organisms <u>C. by using genetic analyses</u>.
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Explanation:</h2>
The following features were used to study about the relationships between different groups of organism:
- External morphology
- Similarities in structure
- Genetic analysis
- Chemical composition
The molecular similarities in the structure of RNA, DNA, and proteins help to establish the relationship of relationships between different groups of organisms. This was studied through testing the samples obtained by organisms using genetic analyses.
The outcome of the gram stain is based on differences in the cell's cell wall(different composition of the cell wall
Answer:
The null hypothesis is a general statement that states that there
is no relationship between two phenomenons under
consideration or that there is no association between two groups.
A hypothesis, in general, is an assumption that is yet to be proved
with sufficient pieces of evidence.
Answer:
A. Their bodies tend to take in too much water.
Explanation:
Osmoregulation is the maintenance of osmotic concentration inside the body cells and in the extracellular fluid by controlling the amount of water and salts. Organisms living in water can be divided into two groups: Some are osmoconformers which change the osmolarity of body fluids with respect to the surrounding medium. Some are osmoregulators which do not allow change in internal osmolarity and try to maintain it by various means.
If as osmoregulator is placed in fresh water environment then their body is hypertonic to their environment. Osmosis will occur which is the movement of water from low solute to high solute concentration. Thus the problems faced by such organisms would be:
- Entry of excess water
- Loss of body salts to outside.
Adaptations in such organisms would be:
- Body cover such as scales or adipose covers
- They do not drink more water
- Excess water is eliminated as dilute urine
- Special cells called ionocytes or chloride cells help in active uptake of sodium ions and chloride ions.
