The bird was frightened by the human as a defense mechanism it knows to fly away for safety.
Answer:
Neither observer nor subjects know which subject receives the vaccine and which receives a placebo
Explanation:
In a double-blind study neither the participants nor the experimenters is aware of who is receiving a particular treatment.
Its used to prevent bias in research results from demand characteristics or the placebo effect
Out of the following given choices;
(1) an increase in the number of clams
(2) a decrease in the number of water plants
(3) an increase in the number of crabs
(4) a decrease in the number of crayfish
The answer is D. Crayfish are are freshwater crustaceans resembling small
lobsters. Clams and crabs are found in marine waters. Most crayfish cannot
tolerate polluted water. Crayfish feed on animals and plants, either living or
decomposing, and detritus, therefore a decrease in small invertebrates in the river
would decrease their food source thence
consequently affect their numbers.
i wish i could help but i dont understand the work you where given maybe ask the teacher for some one on one help???????
Youre not able to determine gender unless given that a specific trait applies to only one gender. The only thing determinable is that there are three striped kittens and one black kitten.