Answer: Organs are grouped into organ systems, in which they work together to carry out a particular function for the organism. For example, the heart and the blood vessels make up the cardiovascular system.
Explanation:
Yes they can. An AB parent can indeed sometimes have an O child. But it is by no means common. In fact it would be fair to say that it is exceedingly rare.
The one exception is in certain Asian groups. Some of these folks have a rare version of the ABO blood type gene called cis-AB. People with this gene version have an AB blood type but can easily have an O child.
Answer: The part of DNA that the teacher was modelling would be the backbone of DNA.
Explanation:
The DNA is made of double helical structure which is twisted. In the structure of DNA two strands are coiled among each other.
The DNA consists of the nitrogenous bases, phosphate groups and deoxy-ribose sugar.
The backbone of DNA is made up of sugar( alternating )and phosphate group.The nitrogenous bases such as adenine, cytosine ,guanine and thymine are joined to the deoxy-ribose sugar.
This backbone part was part that the teacher was making as a model by using two coiled springs.
