Core 2- Patterns In Nature

Question 1

State the cell theory

Answer 1

Cells are the smallest units of
Life
All cells are made up of pre exsistant cells
All living things are made up of cells

Question 2

Structure n function of cell organelles

Answer 2

Organelles are the functional units of cells, all organelles are surrounded by a membrane and have a particular job to do for the cell. Because they are surrounded by a membrane. They are easily indetifiable.

Question 3

ORGANIC CHEMICAL- Carbs

Answer 3

Are compounds consisting of carbon, hydrogen and oxygen atoms. Carbs= energy source in cells. They are broken down to
Glucose when energy is required. When humans eat more carbs it stores as fat. Some carbs are important in cell structure e.g plant cell walls are made up of complex carbs

Question 4

ORGANIC CHEMICALS- lipids

Answer 4

Contain hydrogen and oxygen. There is little oxygen in lipid molecules. Lipids are insoluble in water

Question 5

ORGANIC CHEMICALS- protein

Answer 5

Needed by body for growth and repair. Protein contain atoms of carbon, hydrogen, oxygen and nitrogen. They are lrg molecules made up of sml molecules called amino acid. The structure n function of the cell depend on the proteins from which they are made

Question 6

ORGANIC CHEMICALS- nucleic acid

Answer 6

Contains linked sugar molecules, nitrogen based and phosphate groups. They play an important role in determining heredity. 2 types if nucleic a it’s are : deoxyribonuiec acid found in the chromosome. ribonuclease acid found through out cell theory for the manufacture for proteins

Question 7

Compare diffusion n osmosis

Answer 7

Diffusion- a gradient which exsist when 2 areas have different concentrations if a substance, the substance moves until the two concentrations are equal

osmosis- the passive transport involving the diffusion of water molecules across a selectively permeable membrane. Water will move by diffusion from am area to wear there is more of it to where their is less

Compared- both involved in the passive spreading of the molecules from regions where they are more concentrated to regions where they are less concentrated

Question 8

Explain why cells need to

Be small

Answer 8

Cells need nutrients to grow
The area of this surface affect the rate at which nutrients can enter the cell, as well as the rate at which wastes can leave. The rate of exchange in substances through the membrane Is more efficient than in are cell

Question 9

Fluid mosaic model if cell membranes

Answer 9

Molecules move in and out of cells. Living cells are continual exchanging materials with their external environments

Question 10

Process of mitosis

Answer 10

Division of nucleus which leads to identical copies of each chromosome being passed from norther cell to daughter cells. Process of cell division in human body grows and repairs and maintains.

Question 11

Compare respiration and photo synthesis

Answer 11

Respiration:
Organism- all living things
Organ- lungs ills skin leaves all cells ribosomes
Equation- glucose +oxygen > carbon dioxide + water + energy

Photosynthesis:
Organisms- plants only
Organ- leaves only, chloroplast
Equation- carbon dioxide +water + sunlight > glucose + oxygen

Question 12

Compare light n electron microscopes

Answer 12

Light- mag- up to 1500x
Res- up to 0.2um
Advantage- samples prepared quickly, coloured stains can be used, living cells can be viewed
Disadvantage- limited visible detail.

Electron- mag- 1000 000
Res- up to 0.0003ym
Ad- high mag and res, allows objects as small as molecules to be viewed
Dis- only non living can be seen, electrons must be kept in a vacuum to prevent scattering