The correct answer is the second option. Animals have two major types: vertebrates and invertebrates. Vertebrates are animals that have backbone while the invertebrates do not have one. Examples for vertebrates are birds and mammals while the latter are insects and squid.
The correct option is A.
When an end of a tuning fork that is vibrating is placed against a table, it produces a sounder that is dramatically louder than the original sound produced by the vibrating tuning fork. At this stage, the tuning fork is forcing the table to vibrate at its own frequency. Thus, the statement in option A is not true.
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Answer:</h3>
Vertebrates have backbones, while invertebrates do not.
Humans, for example, are vertebrates because we have backbones.
Answer:
Because older cultures of gram-positive bacteria tend to lose their ability to retain crystal-violet in the peptidoglycan of their cell walls and can be confused with gram-negative bacteria.
Explanation:
Gram staining is used to differentiate between two major groups of bacteria. Gram-positive and gram-negative, these bacteria differ in the amount of peptidoglycan in their cell walls. Gram-positive bacteria have a higher amount of peptidoglycan, which absorbs the violet crystal complex used in gram staining, staining them purple/violet. Old cultures of gram-positive bacteria tend to lose the ability to retain the violet crystal and are stained by safranine, staining them red/pink and appear to be gram-negative.
