Biology all - Aqsa year 9 Exam Questions With Correct And Revised Answers.
3 views 0 purchase
Course
Biology
Institution
Biology
Biology all - Aqsa year 9 Exam Questions
With Correct And Revised Answers.
2.1 describe the levels of organisation in organisms: organelles, cells, tissues, organs and systems
- answerTissues
are a collection of similar cells all serving a common function.
Organs
are made up of several kinds ...
Biology all - Aqsa year 9 Exam Questions
With Correct And Revised Answers.
2.1 describe the levels of organisation in organisms: organelles, cells, tissues, organs and systems
- answer✔✔Tissues
are a collection of similar cells all serving a common function.
Organs
are made up of several kinds of tissues together forming a functioning unit.
Systems
are several organs forming an organ system. Like the cardiovascular system is made up of the
heart, blood and blood vessels.
2.2 describe cell structures, including the nucleus, cytoplasm, cell membrane, cell wall,
mitochondria, chloroplasts, ribosomes and vacuole - answer✔✔NUCLEUS
Membrane-bound organelle that contains genetic material
CYTOPLASM
Material that fills cell to facilitate chemical reactions and hold organelles in place
CELL MEMBRANE
Phospholipid bilayer that controls the movement of substances into and out of cell
CELL WALL
External to cell membrane that protects and maintains the shape of cell (prevents cell from
bursting)
MITOCHONDRIA
Membrane-bound organelle that carries out cellular respiration
CHLOROPLAST
Plastid in plants that carries out photosynthesis
RIBOSOME
Site of protein synthesis
VACUOLE
Storage organelle in plants to store Water and dissolved substances
2.3 describe the functions of the nucleus, cytoplasm, cell membrane, cell wall, mitochondria,
chloroplasts, ribosomes and vacuole - answer✔✔NUCLEUS
Membrane-bound organelle that contains genetic material
CYTOPLASM
Material that fills cell to facilitate chemical reactions and hold organelles in place
CELL MEMBRANE
Phospholipid bilayer that controls the movement of substances into and out of cell
CELL WALL
External to cell membrane that protects and maintains the shape of cell (prevents cell from
bursting)
MITOCHONDRIA
Membrane-bound organelle that carries out cellular respiration
CHLOROPLAST
Plastid in plants that carries out photosynthesis
RIBOSOME
Site of protein synthesis
VACUOLE
Storage organelle in plants to store Water and dissolved substances
2.4 know the similarities and differences in the structure of plant and animal cells -
answer✔✔Plant cell: Fixed shape, large vacuole, cell wall, chloroplast
Animal cell: No fixed shape, little or no vacuole, no cell wall, no chloroplast
2.7 identify the chemical elements present in carbohydrates, proteins and lipids (fats and oils) -
answer✔✔CARBOHYDRATE
CHO
PROTEINS
CHON
2.8 describe the structure of carbohydrates, proteins and lipids as large molecules made up from
smaller basic units: starch and glycogen from simple sugars, protein from amino acids, and lipid
from fatty acids and glycerol - answer✔✔STARCH AND GLYCOGEN
Composed of simple sugars
PROTEIN
Composed of amino acids
LIPID
Composed of fatty acids and glycerol
CARBOHYDRATES
Saccharide unit (sugars)
2.9 practical: investigate food samples for the presence of glucose, starch, protein and fat -
answer✔✔Glucose: Benedicts solution
Place two spatulas of the food sample into a test tube or 1 cm3 if the sample is liquid. Add about
1 cm3 depth of water to the tube and stir to mix.
Add an equal volume of Benedict's solution and mix.
Place the tube in a water bath at about 95°C for a few minutes.
Record the colour of the solution.
Benedict's solution gradually turns from blue to cloudy orange or brick red when heated with a
reducing sugar. Sucrose is a non-reducing sugar and does not react with Benedict's solution
Starch: Iodine test
Place one spatula of the food sample on a dish or 1 cm3 if the sample is liquid.
Using a dropper, place a few drops of iodine solution onto the food.
Record any change in the colour of the solution.
Starch is detected using iodine solution. This turns blue-black in the presence of starch.
Protein: Biuret solution
Place one-two spatulas of the food sample into a test tube or 1 cm3 if the sample is liquid. Add
about 1 cm3 depth of water to the tube and stir to mix.
Add an equal volume of potassium hydroxide solution to the tube and stir.
Add two drops of copper sulfate solution and stir for two minutes.
Record the colour of the solution.
Proteins are detected using Biuret reagent . This turns a mauve or purple colour when mixed with
protein.
Fat: Ethanol test
Place two spatulas of the food sample into a test tube or 1 cm3 if the sample is liquid.
Add 2 cm3 of ethanol to the tube. Cover the end of the tube and shake the tube vigorously.
Allow the contents to settle.
Pour the liquid from the top of the mixture into a test tube half-filled with water.
Record the level of the food and whether the water is cloudy or clear.
A milky-whiteemulsion forms if the test substance contains lipids
2.10 understand the role of enzymes as biological catalysts in metabolic reactions -
answer✔✔Enzymes are proteins which catalyze metabolic reactions as they allow substrates to
bind onto their active site, breaking them down into products
AMYLASE / MALTASE
Starch → Glucose
PROTEASE
Protein → Amino Acids
LIPASE
Lipids → Fatty Acids & Glycerol
2.11 understand how temperature changes can affect enzyme function, including changes to the
shape of active site - answer✔✔-As the temperature increases towards optimum, the rate of
enzyme activity increases due to more kinetic energy and more frequent collisions
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller Brightstars. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $12.49. You're not tied to anything after your purchase.
