cell structure

• what are cells?


  all living organisms are made of cells, they provide structure and carry out certain functions
• what are prokaryotic cells?


  Cells without a nucleus or membrane-bound organelles. such as bacteria
• what are eukaryotic cells?

  Cells with a nucleus and membrane-bound organelles. such as plant and animal cells, also fungi
• what are plasmids in Eukaryotic cells and what do they do?

  Small, circular DNA molecules/rings . They can replicate and move between cells so that genetic info can be shared.
• where is genetic info in prokaryotic cells stored?

  since they don't have a nucleus, genetic material is stored in a single DNA loop in the cytoplasm (watery jelly)
• what do prokaryotic cells not have?

  mitochondria (respiration) and chloroplasts (photosythesis)
• what sub-cellular structures do animal cells contain?

  cell membrane, nucleus, ribosomes, mitochondria, cytoplasm
• what does the cell membrane do?


  separates the inside of the cell from the environment, it is selectively permeable meaning it has control over which substances can enter and exit
• what is the nucleus?

  contains chromosomes which contain the cells genetic material
• what are ribosomes?


  Cellular organelles responsible for protein synthesis. (making protein)
• what is mitochondria?

  where aerobic respiration takes place, aerobic respiration is a process which uses glucose and oxygen to release energy
• what is cytoplasm?


  jelly-like fluid that fills the cell, it is where most chemical reactions take place
• what is the cell wall?


  gives the cell structure
• what sub-cellular structures do plant cells contain?

  Chloroplasts, vacuoles, and cell walls.
• what is a permanent vacuole?

  fluid filled sac that stores water, it is enclosed in the cell membrane and makes up to 90% of the plants volume
• what are chloroplast?


  contain chlorophyll which is needed for photosynthesis and give plants their green colour
• what is a cell wall?

  surrounds the cell and is made of cellulose, the cell wall increases the structural strength of the cell and protects it
• how often do plants differentiate?

  throughout their lives, this means plants are always able to create new tissues
• when do animal cells differentiate?

  early on in their development, in mature animals most cells only divide to replace cells and repair tissues
• what are the sub cellular structures found in a bacteria cell?

  flagella, cell wall, cell membrane, cytoplasm, plasmids
• what is flagella?


  whip-like structures used for movement
• what are some specialised animal cells?

  Sperm cells, red blood cells, muscle cells, nerve cells.
• what are some specialised plant cells?

  Xylem, Phloem, Guard cells, Root hair cells
• how is the middle section of a sperm specialised?

  contains mitochondria to provide the sperm with energy to travel long distances and reach the egg cell
• what is the acrosome in a sperm cell?

  found at the tip of the head and contains the digestive enzymes needed to penetrate an egg cell
• what is the Flagellum on a sperm cell?

  a tail which allows sperm cells to travel towards the egg
• what does the head of the sperm contain?

  the nucleus which carries one half of an organisms genetic material, this combines with the egg cells half of genetic material to fertilise the egg, 23+23=46
• what are algal cells made up of

  Algal cells are eukaryotic and contain three types of double-membrane-bound organelles: the nucleus, the chloroplast, and the mitochondrion.
• what are specialised cells?

  Cells that have specific structures and functions to perform specific tasks in the body.
• what is cell differentiation?

  Cell differentiation is the process by which cells become specialized to perform specific functions in an organism. This occurs as cells develop and mature, and involves changes in gene expression and cell structure.