MOD 2 - Organisation of Living things Flashcards
Why do multicellular organisms live longer
Energy efficient
Tissue
group of similar cells working together to carry out a particular function in a multicellular organism e.g. muscle tissue
Example of a specialised cell
Red blood cells - carry oxygen throughout the body using hemoglobin
Unicellular Organism
only consist of one cell, performs all the survival processes themselves
Multicellular organism
made up of specialised cells, each conducting specific function.
Organ
Two or more tissues that work together to perform a specialised job
Palisade mesophyll
Perform photosynthesis
Leaf structure
Epidermis, cuticle, stomata, mesophyll, vascular bundles
Root structure
Epidermis, cortex, vascular bundles
Epidermis
Single layer of cells on outside of the leaf (upper and lower) - protect cells inside leaf, prevent water loss
Cuticle
Waterproof, prevent water loss
Stomata (stoma)
open and close - pores on underside of leaf
Guard cells
for gas exchange
Palisade layer
Perform photosynthesis
Spongey mesophyll
gas can diffuse - makes sure all cells get nutrients
Vascular bundles
transport materials around the plant
Root epidermis
Outer of roots, covered in epidermis, some cells have root hairs to increase SA:V so mineral and water uptake can be increased
Root cortex
Glucose and starch stored
Where are oxygen and carbon dioxide exchanged from
Alveoli
How does gas exchange occur
via diffusion
Characteristics of respiratory surfaces
Large surface area to increase rate of diffusion
Thin easily penetrable surface
Two types of digestion
Physical and chemical
Proteases
Digestive enzyme in stomach and intestine (responsible for breaking down proteins into amino acids)
What vascular tissue facilitates transport of water through a plant?
Xylem (tubes)
Transpiration - Cohesion - tension theory
movement of water in plants
Translocation
Movement of sugar around plants
Source to sink theory
Transport of sugar in plants - sugar actively transported into the phloem at the “source”, then transported through phloem tubes to the “sink”. Source has a high concentration of sugar, sugar moves to area of lower pressure (sink)
Xylem and phloem
Vascular bundles
Contain xylem and phloem.
Double closed circulatory system
4 chambered heart. Receives blood, pumps into lungs, receives it again to pump around the body.
Pulmonary circulation
transports blood to and from lungs - right ventricle away from heart, into alveoli, oxygenated blood travels back to heart, left atrium.
Systemic circulation
Transports blood to and from body - picks up co2 and waste
Artery
High pressure blood away from heart
Vein
Low pressure blood towards the heart
Semilunar valves
at the exit of ventricles, prevent blood expelled from the heart from flowing back in.
Main component of blood
Plasma
