Biology 1 - Cells and organisation (B1- B4) Flashcards
How many micro meters in a mm?
1000
What is the equation for magnification?
magnification= size of image / size of real object
What does the nucleus do in a cell?
Contains genes and chromosomes and controls activities of the cell
What is the cytoplasm and what does it do?
A liquid gel in which the organelles are suspended and where most of the chemical reactions needed for life take place in the cell.
What does the cell membrane do?
Controls what enters and exits the cell
What do the mitochondria do?
Aerobic respiration takes place here, releasing energy for the cell.
What do the ribosomes do?
Protein synthesis
What is the permanent vacuole?
A space in the cytoplasm filled with cell sap. This is important for keeping the cells rigid to support the plant.
What do plant cells have that animal cells don’t? Two things.
Large vacuole and chloroplasts
What are Eukaryotic cells?
Animal and plant cells are examples - Cell membrane, cytoplasm and genetic material that is enclosed in a nucleus.
What are Prokaryotic cells?
Bacteria are an example. The genetic material is not in a distinct nucleus. It forms a single DNA loop. Prokaryotes may contain one or more extra small rings of DNA called plasmids.
What does the xylem do in a plant stem?
Carries water and mineral ions from the roots to the highest leaves and shoots. The xylem also supports the plant.
What does the Phloem do in a plant stem?
Carries food made by photosynthesis around the body of the plant.
What is diffusion?
The spreading out of the particles of a fluid in a solution. The net movement is from an area of higher concentration to an area of lower concentration of the particle.
How do substances move around cells?
Diffusion
What is Osmosis and how does it differ from diffusion?
The movement of water from a dilute to a more concentrated solute solution through a partially permeable membrane.
What is Active transport?
The movement of substances from a more dilute solution to a more concentrated solution, against the concentration gradient.
How are chromosomes found in body cells?
In pairs.
What is the cell cycle?
The series of stages in which cells divide.
What are the three stages of cell division
Stage 1 - longest stage, Replication of DNA to form two copies of each chromosome and synthesis of new sub-cellular structures.
Stage 2 - Mitosis, the nucleus divides.
Stage 3 - Cell divide in two
What is mitosis?
The division of the nucleus during cell division.
What is a tissue?
A group of cells with similar structure and function.
What is an organ?
Collections of tissues performing specific functions.
What is an Organ system?
A group of organs which work together to form organisms.
What does the liver do in the digestive system?
Makes bile.
What does the Stomach do in the digestive system?
Breaks down large insoluble food molecules into smaller soluble ones
What does the small intestine do in the digestive system?
Breaks down large insoluble food molecules into smaller soluble ones and then absorbs them into the blood.
What does the Large intestine do?
Absorbs water from undigested food.
What colour does starch turn iodine?
Blue-black
What are enzymes?
Biological catalysts that are produced by the body.
What are each broken down by and into:
- Starch (Carbohydrate)
- Proteins
- Fats (Lipids)
- Starch into sugar by amylase
- Protein into amino acids by protease
- Lipids broken down into fatty acids and glycerol by Lipase.
What are the four main components of blood?
Plasma, red and white blood cells and platelets.
What substance in red blood cells holds oxygen?
Haemoglobin
Which blood vessels carry blood to the heart?
Veins
Which blood vessels carry blood to the organs?
Arteries
Which blood vessels are one cell thick?
Capillaries
What do the valves do?
Prevent back flow of blood in the heart.
Where does gas exchange take place in the lungs?
Alveoli
What is transpiration?
The loss of water vapour from the leaves of plants through the stomata when they are opened to allow gas exchange for photosynthesis.
What does protease break down?
Proteins into amino acids.
What does lipase break down?
Lipids into fatty acids and glycerol.
What does amylase break down?
Starch into sugar
How do you test for protein in a food?
Add Biuret reagent to food sample
Mauve/purple colour shows protein is present.
How do you test for glucose in a fruit?
Heat mixture and add a few drops of Benedict’s solution
Glucose turns solution blue to orange.
How does water move from roots to the leaves?
They move up the xylem by the transpiration stream.
What is the effect of chlorophyll deficiency on a plant. (4 points)
- Less photosynthesis
- Less glucose is made
- Less energy released for growth
- Less glucose for respiration so less amino acids / proteins / cellulose for growth
What do the villi do?
Absorbs food molecules from small intestine. Inc. Glucose.
