gwenca.wordpress.com Chapter 2 : Organisa0on of the organism 01 Parts of an animal cell visible under a light microscope • Nucleus • Cytoplasm • Cell membrane 02 Parts of a plant cell visible under a light microscope • Cell wall • Nucleus • Cytoplasm • Chloroplasts • Vacuole • Cell membrane 03 Organelles only found in plant cells (not animal cell) • cellulose cell wall • permanent vacuole • chloroplasts 04 What structures do cytoplasm of all cells contain? • ribosomes • vesicles 05 What structures do all eukaryotes have? • mitochondria • rough endoplasmic reticulum 06 Labelled cell diagram: gwenca.wordpress.com 1 gwenca.wordpress.com 07 Labelled light micrograph of an onion epidermal cell: 08 Function of nucleus • controls all the activities in the cell • contains genetic material DNA 09 Function of cytoplasm and cell membrane • Cytoplasm: - where many chemical reactions take place • Cell membrane: - controls substances entering and leaving cell 10 Function of cell wall & what it is made of • gives cell structure • prevents bursting • cellulose (plants) 11 Function of chloroplasts • site of photosynthesis 12 Function of permanent vacuole • contains cell sap (a solution of sugars and salts) 13 Function of mitochondria • site of aerobic respiration • providing energy in form of ATP 14 Function of ribosomes • site of protein synthesis 15 Function of rough endoplasmic reticulum • produce and transport proteins 16 Function of vesicles • transport materials in the cell gwenca.wordpress.com 2 gwenca.wordpress.com 17 What organelle does a very metabolically active cell likely to have lots of? • Mitochondria as they provide energy through aerobic respiration 18 Magnification 19 How do you convert from μm to mm? • 1000 micrometre = 1 millimetre 20 Ciliated cells • have long and thin cilia (increases surface area) • which beat to move mucus upwards to throat in the trachea and bronchi 21 Root hair cells • absorbs water and ions from soil • have lots of mitochondria to provide energy for active transport • have long extension to maximise the surface area available for uptake 22 Xylem vessels • transport water from roots to rest of the plant • supports the plant • waterproofed with lignin • small diameter to maintain continuous column of water • dead cells do not interrupt the @low of water 23 Nerve cells • transmit nerve impulses • ends contain neurotransmitters to send impulses to other neurones • long axon to transmit impulses long distances • thin to transmit impules faster • covered in myelin sheath to speed up transmission 24 Red blood cells • transports oxygen • no nucleus (more space for haemoglobin) • contains a lot of haemoglobin to carry oxygen • biconcave disc shape (large surface area to volume ratio) • thin membrane minimise diffusion distance gwenca.wordpress.com 3 gwenca.wordpress.com 25 Palisade mesophyll cells • absorb light and carry out photosynthesis • contains lots of chloroplasts • thin and tall so many chloroplasts can be • large vacuole • thin cell wall minimise diffusion distance packed 26 Sperm cell • travel to penetrate and fertilise an egg cell • long @lagellum to help swim to the egg • middle section contains lots of mitochondria which provide the cell with energy for swimming to the egg • an acrosome at the tip containing enzymes to digest the outer membrane of the egg 27 Egg cell • halpoid nucleus: after fusing with a sperm it produces diploid organism • lots of cytoplasm for many divisions • lots of nutrients to support the egg until it reaches the uterus • It contains lots of fats and protein to: - make new cells after fertilisation - make cell membrane - make enzymes - make cytoplasm - fat / protein provide source of energy - energy for cell division • The purpose of the jelly-coating: - changes shape after fertilisation - to prevent entry of other sperm - fuse with a sperm cell for reproduction 28 Tissue • a group of cells with similar structures, working together to perform a shared function 29 Organ • a structure made up of a group of tissues, working together to perform speci@ic body functions 30 Organ system • a group of organs with related functions, working together to perform body functions gwenca.wordpress.com 4 gwenca.wordpress.com 31 Name 3 organ systems in the body 1. respiratory system 2. circulatory system 3. reproductive system 32 What organs make up the digestive system? • Oesophagus • Stomach • Small intestine • Large intestine • Liver • Pancreas • Gallbladder • Anus 33 What organs make up the circulatory system? • heart • lungs • blood vessels 34 What type of tissue is the heart made up of? • cardiac muscle 35 What tissues make up a plant leaf? • Mesophyll tissue (spongy mesophyll & palisade mesophyll) • Epidermis (upper and lower) • Veins (xylem and phloem) gwenca.wordpress.com 5