2.6 Cell adaptations and stem cells Flashcards
What is the function of Erythrocytes and its adaptations
-To transport oxygen around the body
-Biconcave shape for an increased surface area so more space for oxygen to bind.
-no nucleus so can be packed with more haemoglobin
-Elastic membrane to squeeze through small capillaries
What is the function and adaptations of Neutrophils
-Ingest invading pathogens (e.g bacteria and fungi via phagocytosis)
-Twice the size of erythrocytes
-Attracted to infection site by chemotaxis ( the direction of a cell by chemical stimulus)
What is the function and adaptations of squamous epithelial cells
-Flat cells found on the surface where things need to be exchanged e.g the alveoli
-Flat shape means substances can easily pass through
-Have a short cell cycle so can divide quickly
What are the functions and adaptations of ciliated epithelial cells
-Protect the lungs from harmful pathogens and dust
-Have hair-like cilia on the surface which line the trachea
-They sweep mucus (released by goblet cells) with trapped pathogens in them away from the lungs
What is the function and adaptations of a sperm cell
-To fertilise with an ovum
-Contain lots of mitochondria and therefore ATP so they can propel towards an ovum
-Long and thin so can move easily
-Enzyme at the front which can break outer layer of the ovum
-Contain a haploid male gamete at the head
What is the function and adaptations of cartilage
-Provides support and protects your bones and joints
-Strong and flexible
-For e.g its is found in a ring structure in the trachea and helps keep it open allowing you to breath
What is the function of the three types of muscle tissue
Smooth muscle tissue-allow movement, found in the walls of blood vessels, uterus and urinary tracks
Cardiac muscle tissue- allow movement, make up the walls of the heart and allow it to beat and pump blood
Skeletal muscle tissue-joined to bones by tendons when these muscles contract they cause bones to move.
What is the adaptations of Palisade cells?
-Long and cylindrical so pack closely but leave space for air like carbon dioxide
-Large vacuole so chloroplasts are on the edge of the cell for short diffusion distance of carbon dioxide
-Contain many chloroplasts for photosynthesis
-contain cytoskeleton and motor proteins to move chloroplasts closer to upper surface of leaf when light intensity is low and down when high
How do guard cells open the stoma?
-ATP is used to actively transport potassium ions into the guard cell this lowers it’s water potential causing water to flow into the cell
-This opens the stoma so air can enter the spaces within the layer of the leaf and carbon dioxide can diffuse in and oxygen out for photosynthesis
How is the root hair cell adapted to carry out its function?
-Hair like projections increase surface area for absorption
-Mineral ions are actively transported into root hair cells lowering their water potential so water will flow in
-They have special carrier proteins to actively transport mineral ions which can also produce their own ATP
How is the xylem adapted for its function?
-Lignin is deposited into cell walls to reinforce it but it also kills the cells
-The ends of the cell break down so that the xylem produces a discontinuous column
How is the phloem adapted for its function?
-Sieve tube cells lose most of their organelles so sieve plates can develop
-Companion cells contain their organelles and carry out their metabolic functions
What is the epidermal tissue?
-Consists of flattened cells and form a protective covering over leaves
-Some have walls with a waxy substance which forms a cuticle.
What is differentiation and an undifferentiated cell?
-Differentiation is the process of becoming specialized, some genes will be expressed or turned off
-Undifferentiated cell is one that has resulted from mitosis or meiosis
What is a stem cell?
-An undifferentiated, unspecialized cell with the potential to differentiate into a variety of cells
-Essential for growth, development, and tissue repair
-Once a cell is specialized is can’t divide anymore
