B4 Flashcards
Where in the heart is the natural pacemaker found?
Right atrium
How can you identify plant diseases?
Referring to gardening manuals/websites, taking infected plants to a lab, using monoclonal antibody kits
What’s the role of the phloem?
Transports dissolved sugars made in the leaves around the whole plant for immediate use of storage. This is is called translocation
Name an adaption of the root hair cell
A long narrow “protrusion” which increases surface area for absorption
- no chloroplasts, can’t photosynthesise under ground
- extra mitochondria for energy
Name an adaption of the xylem
- hollow tubes of dead plant cells
- strengthened by lignin spirals which support stem and withstand pressure
How is the phloem adapted?
- tubes of elongated cells
- cell sap can move from one phloem to others through pores in walls
- assisted by alive companion cells
Define transpiration
Movement of water from the soil, into the roots, through stem and out of the stomata on the underside of the leaves
Define transpiration
Movement of water from the soil, into the roots, through stem and out of the stomata on the underside of the leaves
Describe the circulatory system
- made of blood, heart and blood vessels
- transports blood around the body, carrying oxygen from the lungs and glucose from digestion to the cells that need them as well as carrying waste substances to be removed
Blood is a tissue containing which components?
- Red blood cells
- white blood cells
- platelets
- plasma
Red blood cells
Carry oxygen
Biconcave shape gives them an increased SA:V ratio for diffusion of oxygen
Red pigment haemoglobin binds to oxygen
White blood cells
Make up immune system, attack invading microorganisms
Platelets
Fragments of cell, causes clotting at the sites of wounds
Plasma
Straw coloured fluid in which the platelets, red and white blood cells are suspended. It carries dissolved CO2 and glucose
Arteries
Take blood away from heart
Strong and can stretch to deal with blood at high pressure
Thick walls made from muscle and elastic tissue
Veins
Take blood into heart
Valves prevent backflow of blood and keep it flowing in the right direction
Capillaries
Tiny vessels found in lungs and body parts, 1 cell thick, allow oxygen and CO2 to diffuse into and out of the blood
What and where is the natural pacemaker found?
Small patch of cells which controls the resting heart rate
Right atrium
What path does blood take from the lungs?
Lungs –> pulmonary vein, LV, LA –> aorta, body –> vena cava, RV, RA –> pulmonary artery, lungs
How is coronary heart disease caused?
Build up of fatty material in coronary arteries, narrowing them. This reduces blood flow through them, resulting in lack of oxygen for the heart muscle
Artificial pacemakers
Treats: irregularities in heart rate
Works by: gives out electrical impulses to control heart rate
Stents
Treats: coronary heart disease
Works by: opens up coronary arteries to keep blood flow to heart muscle
Statins
Treats: high cholesterol that can lead to coronary heart disease
Works by: reducing blood cholesterol levels and slows down rate of fatty material deposit
Replacement valves
Treats: faulty/ leaky heart valves
Works by: 2 types- biological come from pigs/human donors
Mechanical- built from man made materials
Heart transplants
Treats: heart failure
Works by: from human donors- artificial hearts temporarily used when patients wait for transplants, or to rest the heart as an aid to recovery
Respiratory system
Gets oxygen from air into lungs during inhalation and removes waste carbon dioxide from the body during exhalation
What happens at the alveoli?
Gas exchange with the blood
How are alveoli adapted for gas exchange?
Thin walls- reduces distance that oxygen needs to diffuse, increasing rate of diffusion
Huge surface area- tiny size, round shape and large number of alveoli increases surface area, increasing rate of diffusion
Surrounded by capillaries- network of capillaries provides a constant flow of blood, maintaining an oxygen concentration gradient, maintaining a high rate of diffusion
What’s the role of the root hair cell?
Absorbs water by osmosis and mineral ions by active transport from the soil
What’s the role of thr xylem?
Transports water and mineral ions from the roots, through the stem and to the leaves. This is called transpiration
What’s the role of the phloem?
Transports dissolved sugars made in the leaves around the plant for immediate use or storage. This is called translocation
Which factors effect transpiration?
Humidity, light intensity, wind intensity, temperature
How does temperature effect rate of transpiration?
Higher temp increases rate of evaporation of water through the leaves, increasing transpiration
How does humidity effect rate of transpiration?
High humidity means there’s already a lot of water vapour in the air. This will slow down the rate of evaporation from the leaves, reducing transpiration
How does wind intensity effect rate of transpiration?
Stronger air movements increase rate of evaporation from leaves, increasing rate of transpiration
How does light intensity effect rate of transpiration?
Plants respond to bright light by doing more photosynthesis. They open their stomata to get more carbon dioxide in, but in turn, allow more water to evaporate, increasing rate of transpiration
