Chapter 8
What do plants need for photosynthesis?
carbon dioxide and water
Why is our blood red?
because our blood contains a red pigment called haemoglobin.
The function of heart is to .. It is made of a special type of muscle called ...
What is a pathogen?
a microorganism that causes disease.
What is an antibody?
a protein molecule with a particular shape to destroy a particular pathogen.
Water moves into a root hair by ...
osmosis
The main transport system of all mammals is the ..., also known as ...
Define atria and ventricles
Atrium are the upper chambers to collect blood from the body into the heart.
Ventricles are the lower chambers of the heart to pump blood out of the heart and all around the body.
What are transmissible diseases?
a disease that can be passed from one person to another.
Define active immunity and passive immunity
Active immunity is defence against a pathogen by antibody production in the body (having the disease and getting over it, being vaccinated with weakened pathogens)
Passive immunity is a short-term defence against a pathogen by antibodies acquired from another individual (mother to infant, by injection of antibodies)
What is the instrument used to measure the rate of transpiration?
Potometer
Oxygenated blood is blood containing a lot of oxygen from the lungs.
Deoxygenated blood is blood containing only a little oxygen.
Why do ventricles have much thicker, muscular walls than the atria? What are the thickness differences between the walls of the right and left ventricles?
The ventricles pump blood out of the heart and all around the body, so they need thicker walls to help them do this.
The right ventricles pumps blood to the lungs, which are very close to the heart. The left ventricle, however, pumps blood all around the body. The left ventricle has an especially thick wall of muscle to enable it to do this.
Mention the four kinds of pathogens
Viruses, Bacteria, Protoctists, Fungi
The function of valves
to make sure the blood flows in the right direction.
What do xylem and phloem transport?
Xylem transports water.
Phloem transports sucrose and amino acids.
The steps of blood flow
Superior and Inferior vena cava - right atrium - tricuspid valve - right ventricle - pulmonary valve - lungs - left atrium - bicuspid valve - left ventricle - aortic valve - aorta - rest of the body
Define systole and diastole
Systole is when cardiac muscles contract, the heart becomes smaller, squeezing blood out.
Diastole is when cardiac muscles relax, the heart becomes larger, allowing blood to flow into the atria and ventricles.
How do pathogens get into your body?
by direct contact, indirect transmission, and by vectors
Define double circulatory system and single circulatory system
Double circulatory system means the blood passes through the heart twice on one complete circuit.
Single circulatory system means blood passes through the heart only once on a complete circuit.
Define transpiration, transpiration stream, active transport, and translocation
Transpiration: the evaporation of water from a plant
Transpiration stream: when water is constantly being taken from the top of the xylem vessels, to supply the cells in the leaves which reduces the effective pressure at the top of the xylem vessels, so that water flows up them.
Active transport is special carrier molecules in the cell membrane of the root hair carry the mineral ions across the cell membrane into the cell, against their concentration gradient.
Translocation: the movement of sucrose and amino acids in phloem, from regions of production to regions of storage, or to regions of utilisation in respiration or growth
Mention the two types of white blood cells and their definition
Lymphocyte (with a large nucleus): 25% -> make antibodies
Phagocyte (with lobed nucleus): 70% -> engulf pathogens
Explain the definition, structure, and function of the blood components
1. Plasma is the liquid part of blood. Its structure is water, containing many substances in solution. Plasma's function is a liquid medium in which cells and platelets can float, and transports CO2, nutrients, urea, hormones in solution, heat, proteins, antibodies.
2. Red cells has biconcave discs with no nucleus and contain haemoglobin. It is to transport oxygen and small amount of CO2.
3. White cells has variable shapes with nucleus. Its function is to engulf & destroy pathogens and make antibodies.
4. Platelets is the small fragments formed from special cells in the bone marrow with no nucleus. It help in blood clotting.
What are the body defenses to prevent pathogens from entering the body? Give examples.
mechanical barriers (nostrils contain hairs to trap dust that might be carrying pathogen), chemical barriers (sticky mucus, hydrochloric acid), food hygiene (keep animals away from food), personal hygiene (keeping your body clean)
What is CHD, the Factors that increase a person's risk of getting CHD, the Name of the drug for patients with CHD