cells

• Eukaryotic vs. Prokaryotic


  Eukaryotic cells contain membrane-bound organelles, such as the nucleus, while prokaryotic cells do not. Differences in cellular structure of prokaryotes and eukaryotes include the presence of mitochondria and chloroplasts, the cell wall, and the structure of chromosomal DNA.
• Name a feature of a prokaryotic bacteria cell


  Flagellum
• diagram of a plant cell,

  
• Diagram of an animal cell

  
• Bacteria cell diagram

  
• what is the job of the cell wall?


  prevents cells from bursting, protect the cell, keeps the cell in shape
• what does it mean the cell membrane is selectively permeable?

  it means that the membrane allows certain substances to pass through while restricting others.
• what does the large vacuole do in a plant cell


  storage of water
• is a plant cell eukaryotic?

  true, it has a nucleus
• compare the structure of red blood cells to plant cells 


  Red blood cells in animals are small, biconcave discs without a nucleus, designed to carry oxygen efficiently due to their large surface area. Plant cells have a cell wall made of cellulose, a nucleus, chloroplasts for photosynthesis, and large vacuoles for storage. Both have cell membranes, but their structures reflect their roles in different organisms' functions and environments.
• what cells do not contain chloroplasts?

  Root cells do not contain chloroplasts
• Name one structure which is present in both plant cells and fungal cells but not in animal cells.


  cell wall
• Name the cells that control the opening and closing of the stomata.

  Guard cells: these cells surround the stoma and change shape to regulate the opening and closing of the stoma.
• role of the red blood cell


  transport oxygen around the body
• the role of white blood cells is...


  engulf pathogens, produce antibodies and antitoxins
• What is a tissue? 


  A group of cells working together to perform a shared function, and often with similar structure. 
• what are stem cells?


  Stem cells are cells with the potential to develop into many different types of cells in the body
• Name the type of tissue in plants that contains stem cells?

   meristem tissue.
• what is the use of stem cells?

  Stem cells are used for treating diseases, repairing tissues, and in scientific research. They can turn into different cell types, which helps in treatments for conditions like blood disorders or injuries.
• what is meiosis?


  Meiosis is a type of cell division that produces gametes (sperm and egg cells in animals, pollen and ovules in plants). It reduces the chromosome number by half, resulting in four non-identical daughter cells, each with half the number of chromosomes as the original cell. 
• what is mitosis?


  Mitosis is a type of cell division that results in two identical daughter cells, each with the same number of chromosomes as the original cell.
• what is the difference between meiosis and mitosis?

  Chromosome Number: Mitosis maintains the same number of chromosomes (diploid to diploid). whereas Meiosis reduces the chromosome number by half (diploid to haploid).

  Number of Divisions: Mitosis has one division, resulting in 2 identical daughter cells. Meiosis has two divisions, resulting in 4 non-identical daughter cells
• what are the uses of mitosis?

  1. Growth: Allows organisms to grow by increasing the number of cells.

  2. Repair: Replaces damaged or dead cells, such as skin cells after an injury.

  3. Asexual Reproduction: In some organisms, mitosis produces offspring without fertilization
• what are the uses of meiosis?

  1. Production of Gametes: It creates sperm and egg cells in animals, and pollen and ovules in plants, which are essential for sexual reproduction.

  2. Genetic Variation: Meiosis introduces genetic diversity through processes like crossing over, leading to unique combinations of genes in offspring.
• Some antibiotics work because they damage the bacterial cell wall. The bacteria die because the cells burst. Explain why the cells burst.

  water enters the (bacterial) cell by osmosis so damaged / no cell wall cannot withstand pressure of the water
• which contains a nucleus prokaryotic or eukaryotic?

  Eukaryotic
• what Controls the movement of substances into and out of the cell?

  cell membrane
• what is meant by a cell membrane is semi permeable?

  the cell membrane is semi-permeable, meaning it allows some substances (like water and gases) to pass through while blocking others. 
• what is the purpose of mitochondria?

  (site of aerobic) respiration
• What is the function of chloroplasts?

  The function of chloroplasts is to carry out photosynthesis. they contain chlorophyll to absorb sunlight
• what is the purpose of the stomata?

  allow gas exchange in plants. They let carbon dioxide enter for photosynthesis and oxygen exit as a by-product. 
• what is the purpose of the Cytoplasm?

  The cytoplasm is the jelly-like substance inside a cell where most of the cell’s chemical reactions happen. 
• what is the purpose of the cell wall?

  provides structure and support to the cell, preventing it from bursting.
• Name one structure which is present in both plant cells and fungal cells but not in animal cells.

  cell wall
• Name the process by which these stem cells then form specialised cells.

  Differentiation of stem cells
• Give two similarities between the prokaryotic cell and the eukaryotic

  1. Both have a cell membrane to control the movement of substances in and out.

  2. Both contain ribosomes for protein synthesis.
• what is the purpose of mitochondrion in animal cells?

  the site of aerobic respiration in animal cells. It releases energy in the form of ATP
• Name the cells in a leaf that control the rate of water loss.

  guard (cells)
• what stops the cell from bursting?

  The cell wall in plant cells and the cell membrane in animal cells play crucial roles in preventing the cell from bursting.
• Describe how red blood cells are adapted to their function

  1. Biconcave shape - Increases surface area for efficient gas exchange.

  2. No nucleus - Provides more space for haemoglobin, which binds oxygen.

  3. Flexible membrane - Allows them to squeeze through narrow capillaries.

  4. Haemoglobin presence - A protein that binds oxygen to form oxyhaemoglobin.

  5. Thin membrane - Enables quick diffusion of oxygen and carbon dioxide.