B1 cell biology Flashcards

Question

The cell cycle

Answer 1

1. The cell grows. No. Of sub cellular structures increases 2. DNA replicates to form 2 copies of each chromosome 3. Further growth and cell checked for errors 4. Mitosis- the chromosomes move apart and 2 nuclei form 5. Cytoplasm divides to make 2 identical cells 6. Temporary cell resting period, doesn't divide

Answer 2

As cells divide, new cells acquire certain features for their specific function. A cells shape,size and internal structure are adapted for its role. Most animal cells differentiate at an early stage

Answer 3

``` Head Acrosome- contains enzymes to penetrate the egg Nucleus- 23 chromosomes Mitochondria- in spiral for energy Tail for movement Cell membrane 55 nano metres long 3 nano metres wide ```

Answer 4

``` Extensions that communicate with other nerve cells Nucleus Fatty covering- the myelin sheath Main part of cell(cell body) Gap I'm myelin sheath- the nerve impulses jumps from one gap to the next making it quicker. Branches that connect with a muscle Motor nerve cell length 1m diameter 1-20 nano metres ```

Answer 5

Mitochondria- provide energy for muscle contraction Protein filaments- slide over each other to produce muscle contraction The cells that make up a skeletal muscle fibre physically join together during their development

Answer 6

Give the cells of a heart and skeletal muscle a striped appearance. In smooth muscle, found in the circulatory system, there are fewer filaments, which are thinner and less well organised

Answer 7

Cell Tissue - lots of cells Organs- tissue grouped together Organ system- organs working together

Answer 8

A damaged cell that divides uncontrollably.

Answer 9

Slow growing Often have capsule around so easy to remove Not cancerous and rarely spread Can press on other body organs and look unsightly

Answer 10

Grow faster Can spread to other body tissues As it grows, cancer cells detach and can form secondary tumours in other parts of the body.

Answer 11

Chemicals and other agents that cause cancer called carcinogens They damage the DNA causing mutations If it isn't discover in the cell cycle it continues to spread.

Answer 12

Viruses Chemicals in the home,industry or environment Ionising radiation Ultraviolet radiation Lifestyle choices eg. Alcohol, smoking, diet

Answer 13

Unspecialised cells that can produce many different types of cells

Answer 14

Injuries eg. Spinal injuries leading to paralysis Conditions in which the body cells degenerate eg. Alzheimer's disease, diabetes and multiple sclerosis Cancers, or following treatments for cancer such a chemotherapy or radiation eg. Leukaemia Produce red blood cells

Answer 15

Removed from a living human embryo Religion doesn't agree with this as life starts at contraception Law says embryos can be created purely for scientific research

Answer 16

If a stem cell is taken from a bank to which other people have contributed the patients body may reject it. A current solution is to find a close match between donor and patient. Or give drugs to suppress Immune system. A possible source is blood left in the umbilical cord and placenta after baby is born. It is easy to collect and store.

Answer 17

Producing stem cells with the same genes as the patient. So it wouldn't be rejected. Requires nuclear transfer.

Answer 18

``` Human egg has nucleus removed and combined with the nucleus of the patient. Cell is simulated to divide Embryo produced is grown. After 4-5 days stem cells are removed Stem cells from the embryo are cultured ```

Answer 19

How successful would it need? After 60 divisions mutations have been observed Virus could transfer with stem cell leading to infection Is it morally right to create an embryo with the intent of destroying it Could an embryo simple be a resource for researchers Are there more positives than negatives Does it give patients false hope

Answer 20

Protein molecule- helically coiled nucleic acid molecule with protein coat. Virus- has lipoprotein envelope around it.

Answer 21

Cells die or become damaged A eukaryotic organism reproduces by asexual reproduction Cancer cells divide Eukaryotic cells are cloned

Answer 22

Drive chemical reactions needed to keep them alive, including building large molecules For movement ( make our muscles contract) For keeping warm Cell division Maintain constant environment Active transport Transmit nerve impulses

Answer 23

Uses glucose to create heat (ectothermic reaction) Glucose+oxygen}carbon dioxide + water C6H12O6+6O2}6CO2+6H2O Starts in cytoplasm then in mitochondria Respiration with oxygen

Answer 24

Respiration without oxygen In cytoplasm of cell Anaerobic respiration in yeast cells and other micro organisms is called fermentation

Answer 25

Glucose} ethanol+carbon dioxide | Anaerobic isn't as efficient a as aerobic

Answer 26

Glucose}lactic acid Incomplete oxidisation cases a build up of Latin acid and oxygen debt. The acid is taken to the liver by the blood where it is oxidised to co2 and waterproof converted to glucose then glycogen. Glycogen levels in the muscles and liver are then restored Needs oxygen to repay debt

Answer 27

Best to grow them in large numbers to study them. Bacteria grow in culture, in or on a culture medium This is either a liquid nutrient broth or a gel agar

Answer 28

All equipment must be sterilised The inoculating loop must be sterilised by passing it through a Bunsen flame before and after use The lid of the agar plate must be secured, but not sealed using adhesive tape Agar plates must be sterilised in an autoclave before disposal This is an aseptic technique

Answer 29

Prokaryotes divide into 2 rapidly to form a colony

Answer 30

Lag phase- no reproduction. Bacteria copying DNA and proteins within their cell Exponential growth phase Stationary phase- resources become scarce so bacteria dies at same rate produced Death phase- bacteria poisoned by build up of toxins in the culture

Answer 31

Disc diffusion technique Agar plate inoculated with bacterium being tested (spread over plate evenly) A disc of antibiotic is placed on the plate Different concentrations are put on plate as well

Answer 32

Lab- mueller-Hinton agar with blood For human pathogens 37 degrees Celsius School- normal agar plate Bacteria (don't want to grow pathogens) 25 degrees Celsius

Answer 33

A sample bacteria for testing must be representative of the population of bacteria Clear zones will be uniformly circular Measurements made with ruler or callipers If there is poor growth becomes anomalies

Answer 34

Agar plate inoculated with bacteria with different disks with different disinfectants and a control Inoculate at 25 degrees Celsius See which has the biggest clear zone as it is most effective for bacerierium staphylococcus aureus in hospitals

B1 cell biology Flashcards

(58 cards)