Answer:
a) Teeth arose from the rough scales of ancestral sharks.
b) Skeletal developments leading to the amphibian movement onto land probably evolved from lobe-finned fishes.
d) The anterior gill arch formed the basis for the evolution of the vertebrate jaw.
Explanation:
The animals we know today have physical characteristics that are evolutionary adaptations of characteristics of their ancestors, which have undergone a series of evolutions and modifications over the years giving rise to new species that have resulted in the species we know today. This process of evolutions and adaptations also happened with the ancestral species of fish, which allowed that today, they had characteristics such as teeth and jaws. Many of these evolutions occurred even in different species, such as the evolution that allowed the amphibians to have a skeleton, which evolved from the spine fins of fish.
Answer:
corrugated cardboard tube - digestive tract
irregular surfaces on the corrugated tube - villi
pump - heart
Plastic tubing - blood vessels
Explanation:
The corrugated cardboard tube represents the digestive tract. The give away was the presence of the irregular surfaces within the tubes. This is called the villi. The villi is responsible for the absorption of food after digestion into the body.
Irregular surfaces on the corrugated tube represent the villi. They are tiny hair-like structures that are in the small intestine, that are responsible for the absorption of food into the bloodstream.
The pump represents the heart. The heart is the only organ in the body that provides the pressure force that pushes the blood throughout the body. In this model, the pump will most likely be performing the same function.
The plastic tubings are meant to contain one form of fluid or the other. Judging from that, they can be said to represent the blood vessels. This is because they are connected to the heart and are meant to transport bodily fluids around the body
MRNA is a short lived form of genetic information that is used in transcribing the genetic information, hence it is not very useful for analysis since it is fragile and wrong transcriptions happen quite often. SNPs (Single Nucleotide Polymorphisms) are a form of genetic mutation; they are more frequent than most other mutations since a single transription error may lead to this. While SNPs are important in genetic analysis and getting information about causes of disease, they are not very helpful in determining your maternal lineage. Similarly, while nuclear DNA contains a large portion of our genetic information, half of it is from our fathers and half from our mothers, so the analysis becomes hazy very soon. Mitochondrial DNA instead is directly passed down from mother to her offspring since the embryo contains only the mitochondria of the ovary. Thus, studying differences between mitochondrial DNA, one can gain information about his maternal lineage and go back to Mitochondrial Eve, the person from which all living persons have gotten their mitochondria from. Thus, the correct answer is c.
From the dendrites to the axon terminals in the sequence of firing
