Biology 1 Flashcards
Where is the DNA found in the cell?
In the chromosomes in the nucleus
How do we normally find chromosomes in the body?
In pairs (23 in humans)
What are the basic stages of cell division?
- Genetic material doubles
- Increases the number of sub-cellular organelles
- DNA replicates
- Mitosis occurs - where the genetic material moves to either end of the cell
- Divides into 2 cells
What is a stem cell?
An unspecialised cell
What can adult stem cells become?
Blood cells or skin cells and some others
What can embryonic cells become?
Any type of cell
What are stem cells in plants called?
Meristem cells
What is a risk of using stem cells in medical treatment?
Transfer viral infection
Which organ system is responsible for our absorbing nutrients?
Digestive system
How does the body breakdown large food molecules into easily absorbable small molecules?
Enzymes - they are specific to each type of nutrient
What is the lock and key theory of enzymes?
Only certain substrates fit the active site of the enzyme - we refer to this as specificity
Carbohydrase breaks down what?
Carbohydrate
Lipase breaks down what?
Fats
Protease breaks down what?
Protein
What type of organ system is made up of the heart and blood vessels?
Circulatory system
Why is the heart part of a double pump system?
The heart pumps blood to the lungs and then to the rest of the body. The blood travels through the heart twice in one complete loop
What type of vessels move away from the heart?
Arteries
What type of vessels move towards the heart?
Veins
Blood carries what?
Oxygen, carbon dioxide, dissolved nutrients and urea
What are the 2 types of blood cell?
Red blood cells - carry oxygen
White blood cells - fight off diseases
What is health?
Health is a state of mental and physical wellbeing
What types of disease are there?
Communicable and Non-communicable diseases.
What are the four types of pathogen?
Virus - HIV
Bacteria - Salmonella
Funghi - Athletes foot
Protists - Malaria
What do viruses and bacteria do in the body?
Reproduce rapidly, take over cells, and can produce toxins to make you feel unwell
What type of disease is measles?
Measles is a viral infection, it presents with red spots and fever.
What type of disease is HIV?
HIV is a viral infection that presents like flu initially and can be treated with retroviral drugs
What type of disease if TMV?
Tobacco mosaic virus is a virus, it affects tobacco plants and tomato plants as they are related. It leads to discolouration of the leaves which reduces photosynthesis
Salmonella and Gonorrhoea are both what type of disease?
Bacterial. Salmonella bacteria are ingested from poorly handled or undercooked food. Poultry are vaccinated against salmonella. Gonorrhoea is an STD which can be treated with antibiotics and is spread by sexual contact
Rose black spot is what type of disease?
Rose black spot is a funghal infection that affects rose plants. It affects the growth of the plant and reduces the amount of photosynthesis that can occur.
Malaria is what type of disease?
Malaria is a protist which is spread by mosquitos. Malaria can be fatal and presents with a fever. Preventing breeding of mosquitos and use of mosquito need reduces the spread of the disease.
What are the physical defence systems of the human body?
Skin, Nose, Trachea, and Stomach
How do white blood cells help protect the body?
Phagocytosis
Antibody Production
Antitoxin Production
How do vaccines work?
A small sample of dead or inactive virus is injected into the body, which stimulates the white blood cells to produce antibodies. the memory white blood cells can respond quickly if the body is infected again with the same pathogen
Should antibiotics be used with viruses?
no, they do not work with viruses
How are drugs developed?
Extracted from plants (such as foxgloves) for drugs like digitalis. Willow helps produce anti-inflamatory aspirin and pencilin mould is used to produce antibiotics.
Most new drugs are synthesized by chemists
How are drugs trialled?
They are tested for toxicity, efficacy and dosage.
- Very low doses are administered to see if the drug is safe.
- If safe, further invesigation is done to determine the effective dose.
- Then a double blind trial is conducted to determine effectivness.
What is the word equation for photosynthesis
Carbon Dioxide + water –> Glucose + Oxygen
What is the chemical symbol for glucose?
C6H12O6
Is photosynthesis endothermic or exothermic?
Endothermic, energy is needed for the reaction to occur
What four factors affect photosynthesis?
Temperature
Light intensity
Carbon Dioxide concentration
Number of chlorophyll
