differentiation (animals) Flashcards
what is differentiation
process by which a cell becomes specialised to its function by the expression of particular genes
how are blood cells specialised (erythrocytes)
-small so large SA:vol ratio for gas exchange
-no nucleus and full of haemoglobin
-biconcave
how are white blood cells specialised (neutrophils)
-contain lobed nucleus = flexible to squeez through tissue
-attracted to infected sites by chemotaxis
-many lysosomes in cytoplasm containing digestive enzymes to break down engulfed particles
how are sperm cells specialised
-many mitochondria for propulsion
-acrosome digestive enzymes to break down lining of egg
-head contains haploid male gamete nucleus
how is squamous epithelium specialised
-line surfaces e.g lungs
-flattened cells = thin for diffusion of gases
how is ciliated epithelium specialised
-found in airways
-cilia can move to waft mucous out of the airways
what are some types of animal tissue
-epithelium tissue
-connective tissue (cartilage)
-muscle tissue
-nervous tissue
what are the features and functions of epithelium tissue
-lining tissue
-cells very close to eachother and form continuous sheets
-no blood vessels within
-carry out function of protection, absorption, filtration, excretion and secretion
what are the features and functions of muscle tissue
-specialised to contract
-has many blood vessels= because they are metabolically active and require an abundant supply of oxygen and nutrients
-fibres elongated and contain special organelles called myofilaments made of protein; actin and myosin = allow muscle tissue to contract
what are the features and functions of connective tissue / catilage
-hold structures together, provides support
-consists of non-living extracellular matrix containing collagen and elastin and polysaccharides = enables it to withstand forces e.g weight
-examples- cartilage, bones, tendons, blood, ligaments
what are the features and functions of nervous tissue
made up of elongated cells with the ability to generate and conduct electrical impulses
-for ; sensory input, integration and communication to control muscles and glands, homeostasis and mental activity
what are the three types of muscles
explain
-skeletal; attached to the skeleton, for movement, packaged by connective tissue joined o bones by tendons
-cardiac; make up walls of heart , allow heart to beat and pump blood around
-smooth; in walls of intestine, blood vessels , uterus and urinary tracks, helps with digestion and nutrient collection
what are the types of cartilage and where are they
-hyaline- forms c shaped rings of trachea, embryonic skeleton and found in nose and ends of long bones
-fibrous - occurs between vertebrae discs and the knee
-elastic - makes up the outer ear and epiglottis
