The correct answer is C, oxygen. Oxygen was once harmful and used to cause harm to the DNA in primitive organisms.
Later on, the bacteria developed enzymes that prevented their DNA from damaging action of oxygen. Afterward, they evolved to use it for cellular respiration.
She is able to determine it to be a mollusk because Mollusks
characteristics are the following:
Term from Latin meaning “soft”
Has a mantle and cavity (breathing and excretion)
Radula (band like an antenna) is present
<span>Structure of the nervous system (brain wraps the
esophagus and has two nerve chords)</span>
Answer: Allopatric speciation , by geographical isolation
Explanation:
Allopatric speciation occurs when two populations are separated by geographical barrier from one another.
The differences in their traits as new species, is due to influence of selective pressures in their individual new environments on the morphological, physiological and behavioural features leading to the formation of a new species..
Answer:
1. Integumentary System
2. Digestive System and Endocrine System
Explanation:
An organ system combines multiple organs to perform one or more biological functions.
The integumentary system which human skin, is an organ system that protects the outer body. So the stretch marks women experience during pregnancy are evident on the skin, and since it was mentioned in the question that "A mother's body undergoes many changes to accommodate the developing fetus during pregnancy" it can be concluded that the skin stretched due to fetus development.
The digestive system here, the liver, can get disordered by a liver disease known as Cholestasis, which alters the flow of bile produced by the liver for digestion and can lead to bilirubin buildup poisoning blood and causing itchiness that can be experienced during pregnancy.
The Endocrine system is the Hormone center of the body, it affects the mood, and can cause itchiness too.