Out of the following give choices;
a. All DNA strands
contained only the heavy nitrogen isotope.
b. Half of the DNA strands contained only the light nitrogen
isotope.
c. All DNA strands contained both heavy and light nitrogen
isotopes.
d. All DNA strands contained only the lighter nitrogen
isotope.
The answer is b. Meselson–Stahl experiment demonstrated the semi-conservative model of DNA replication.
When DNA is replicated, one strand of the new double
helix strand is the parent's strand while the other is the newly synthesized
one. This made the semiconservative model stand out over the other two, dispersive
and conservative models.
Ans.
Cognitive development is defined as the making-up of thought processes, such as decision-making, problem solving, and remembering processes, from childhood to adulthood through adolescence.
The approach of cognitive development, which includes the goal to understand the human thinking by study of encoding, recovery, and storage of information, is known as information processing.
Thus, 'Dr. Marquette has take information processing approach of cognitive development in her studies.'
I would say B.
A, umm, don't crash trains, that's bad.
C, Lillian is wondering how fast a train can go, not at what curve will it fall.
D, Lillian isn't wondering about the size of the trains, just the speed.
A controlled experiment is when the experimenter can change one variable in the experiment and completely change the results.
Redi experiment involved a closed jar with rotting meat on the inside. He waited for a few days and found no new forms of life in the jar.
He then did the same experiment, but this time he took the lid off the jar. After those few days he found there were maggots in the rotting meat from flies.
This is a great example of a controlled experiment, because he only had to change one variable to completely change the results. In this case that variable was just removing the lid from the jar.
Redi was trying to prove spontaneous generation with his experiment. Although, it failed.
Spontaneous generation: When life forms from non-livings.
Redi disproved spontaneous generation, but proved biogenesis.
Biogenesis: When life comes from other living beings.
He proved biogenesis because the flies had reproduced when the jar was opened.
"genotype (n.) the particular alleles at specified loci present in an organism. Synonyms: constitution. makeup." Hope this helps
