Answer: question 6
Explanation: Biogeography The fossil record, Embryology, similarity and vestigial structures, genetics and Observable evolution on small timescales.☺
Answer: The Heart
Explanation:
The blood circulatory system (cardiovascular system) delivers nutrients and oxygen to all cells in the body. It consists of the heart and the blood vessels running through the entire body. The arteries carry blood away from the heart; the veins carry it back to the heart. The system of blood vessels resembles a tree: The “trunk” – the main artery (aorta) – branches into large arteries, which lead to smaller and smaller vessels. The smallest arteries end in a network of tiny vessels known as the capillary network.
There are two types of blood circulatory system in the human body, which are connected: The systemic circulation provides organs, tissues and cells with blood so that they get oxygen and other vital substances. The pulmonary circulation is where the fresh oxygen we breathe in enters the blood. At the same time, carbon dioxide is released from the blood.
Blood circulation starts when the heart relaxes between two heartbeats: The blood flows from both atria (the upper two chambers of the heart) into the ventricles (the lower two chambers), which then expand. The following phase is called the ejection period, which is when both ventricles pump the blood into the large arteries.
In the systemic circulation, the left ventricle pumps oxygen-rich blood into the main artery (aorta). The blood travels from the main artery to larger and smaller arteries and into the capillary network. There the blood drops off oxygen, nutrients and other important substances and picks up carbon dioxide and waste products. The blood, which is now low in oxygen, is collected in veins and travels to the right atrium and into the right ventricle.
This is where pulmonary circulation begins: The right ventricle pumps low-oxygen blood into the pulmonary artery, which branches off into smaller and smaller arteries and capillaries. The capillaries form a fine network around the pulmonary vesicles (grape-like air sacs at the end of the airways). This is where carbon dioxide is released from the blood into the air inside the pulmonary vesicles, and fresh oxygen enters the bloodstream. When we breathe out, carbon dioxide leaves our body. Oxygen-rich blood travels through the pulmonary veins and the left atrium into the left ventricle. The next heartbeat starts a new cycle of systemic circulation. Below is an attachment of a diagram that explains the connection between pulmonary and systemic circulation from google.
Answer:
The water potentials (Ψ) of the cell and its surroundings are the same.
Explanation:
When a cell is kept in hypotonic surroundings such as distilled water, the osmotic movement of water occurs towards the cell. The entry of water makes the cell swell up and it becomes turgid. Water potential is determined by solute and pressure potentials mainly. Here, the solute potential of the cell and the distilled water was different resulting in differences in their respective water potential values which in turn served as a driving force for endosmosis.
When the cell is fully turgid, the solute concentration of the cell and the surrounding distilled water become equal to each other. Under these conditions, the water potential of the cell and distilled water are the same.
Answer:
Explanation:
Bonds form when atoms share or transfer valence electrons. In a covalent bond, two atoms share one or more electrons. Water is a polar molecule. A hydrogen bond is a relatively weak bond between two oppositely partially charged sides of two or more molecules.