Pre Flashcards
(75 cards)
What is one structural role of protein in living organisms?
Production of hair, skin, and nails.
Why do organisms need nitrogen?
Essential for building DNA, RNA, and protein.
What family of plants has a symbiotic relationship with nitrogen-fixing bacteria?
Legume plants.
What is a biological similarity between the nitrogen cycle and the carbon cycle?
Both rely on microorganisms.
What is meant by the term genetic engineering?
Artificial manipulation of genes.
What happens in the isolation stage of genetic engineering?
Target gene from donor is identified and removed, plasmid from bacterium is removed and acts as a vector.
What happens in the expression stage of genetic engineering?
The gene causes the production of a protein (product).
What is the function of plasmids in genetic engineering?
Act as vectors to transfer foreign DNA into host cells, enabling gene cloning and expression. They also contain antibiotic resistance markers for identifying modified cells.
What enzyme is involved in the ligation stage of genetic engineering?
DNA ligase.
What is one application of genetic engineering in animals?
Production of genetically modified (GM) animals for medical research, such as mice engineered to model human diseases (e.g., cancer, Alzheimer’s).
What is one application of genetic engineering in microorganisms?
Production of insulin. Genetically modified E. coli bacteria are used to produce human insulin for diabetes treatment.
How do valves help move blood through veins?
Prevent back flow of blood.
How do muscle fibres help move blood through veins?
Allow expansion to increase blood flow and can withstand pressure; the elastic fibres reshape the vessel.
Name the type of tissue that lines blood vessels
Endothelium
State a function of the lymphatic system
Returns excess tissue fluid from cells to the bloodstream
Give a way lymph differs from blood
Blood: red as it contains haemoglobin in red blood cells, contains red blood cells (RBCs), which are responsible for carrying oxygen throughout the body.
Lymph: pale yellow, consists of white blood cells (mainly lymphocytes), fats, and excess tissue fluid but does not contain red blood cells.
In which zone of the root tip is water absorbed from the soil?
Root hairs
Name the process by which water is absorbed from the soil
Osmosis
Name the vascular tissue that transports water in roots
Xylem
Give one way the xylem is adapted to transporting water
By having lignified cell walls, which provide strength and prevent collapse under pressure.
Name the process by which minerals are absorbed from the soil
Active transport
Write a sentence on how mature red blood cells are adapted to their function
They are disc shaped which increases their surface area, this allows more oxygen to be transported around the body.
Write a sentence on why turgor pressure is important to plants
Turgor pressure is important to plants as it helps maintain cell shape and rigidity, preventing wilting.
Describe how you investigated the effect of heat denaturation on the enzyme catalase
Blend celery with water, then filter to extract the catalase solution. Boil one portion of the catalase solution for 5 minutes to denature it, while keeping another portion at room temperature as a control. Add equal volumes of hydrogen peroxide and pH buffer to two separate test tubes. To one test tube, add the boiled catalase, to the other, add the unboiled (active) catalase. Measure the foam (oxygen bubbles) produced over a fixed time (e.g., 1 minute) using a graduated cylinder.