Unit 2 - Multi-cellular organisms

Question 1

What are cells?

Answer 1

The living units from which all organisms are made

Question 2

How many organelles does an animal cell have and what are the organelles?

Answer 2

5 - nucleus, cytoplasm, cell membrane, ribosomes, mitochondria, cytoplasm.

Question 3

How many organelles does a plant cell have and what are the organelles?

Answer 3

8 - nucleus, cell membrane, ribosomes, mitochondria, cytoplasm, cell wall, chloroplast, sap vacuole.

Question 4

How many organelles does a bacteria cell have and what are the organelles?

Answer 4

6 - cell membrane, ribosomes, cytoplasm, cell wall, plasmid, DNA (also the flagellum and capsule which is not really classed as structures in the cell)

Question 5

How many organelles does a fungal cell have and what are the organelles?

Answer 5

7 - nucleus, cytoplasm, cell membrane, ribosomes, mitochondria, vacuole, cell wall

Question 6

What are single celled organisms?

Answer 6

bacterial

Question 7

What are multi-cellular organisms?

Answer 7

human

Question 8

What is diffusion?

Answer 8

Diffusion is the movement of liquid or gas molecules down a concentration gradient from a region of higher concentration to a region of lower concentration until the concentrations are both equal.

Question 9

What is the structure, arrangement and purpose of the cell membrane?

Answer 9

The cell membranes are extremely thin and are made of phospholipids and proteins. The lipids form two layers called a bi-layer of molecules which are mobile. The arrangement of proteins are found scattered as a mosaic in and around the lipid layers and they can move around the membrane, for this reason they membrane is described as fluid mosaic.The cell membrane controls/selects what enters and leaves the cell as it is selectively permeable.

Question 10

What is the test for starch?

Answer 10

Iodine solution

Question 11

What is the test for glucose?

Answer 11

Benedict’s reagent

Question 12

What is osmosis?

Answer 12

Osmosis is the movement of water molecules from a region of higher water concentration to a region of lower water concentration across a selectively permeable membrane

Question 13

What happens when plant cells gain water by osmosis?

Answer 13

This fills the large vacuole which forces the cell membrane out against the cell wall and the cell has now became turgid.

Question 14

What happens when plant cells lose water by osmosis?

Answer 14

The large vacuole empties and pulls the cell membrane away from the cell. This is called plasmolysis and the cell is now said to be plasmolysed.

Question 15

What happens when animal cells gain water by osmosis?

Answer 15

As there is no cell wall the cell membrane eventually ruptures and the cell bursts.

Question 16

What happens when animal cells lose water by osmosis?

Answer 16

The cell shrinks.

Question 17

What is active transport?

Answer 17

Transport where energy is required by proteins to move molecules or ions across a selectively permeable membrane from a region of lower concentration to a region of higher concentration against the concentration gradient.

Question 18

What are the 4 DNA bases?

Answer 18

Adenine, Cytosine, Guanine, Thymine

Question 19

What do DNA molecules carry?

Answer 19

The different codes for different amino acids and therefor, codes for a protein.

Question 20

What is a gene?

Answer 20

a section of DNA which codes for a protein. Each gene carries the genetic code for making one protein. Genes carry the genetic instructions to make all the proteins required to build an organism.

Question 21

What are proteins?

Answer 21

long chains of amino acids

Question 22

What determines the protein which is produced?

Answer 22

The sequence of amino acids, which is determined by the sequence of bases.

Question 23

What doe mRNA do?

Answer 23

mRNA carries the code for building a specific protein from the nucleus to the ribosome in the cytoplasm where the protein is assembled form amino acids, therefor acting as a messenger.

Question 24

What is mRNA bases?

Answer 24

Adenine, Guanine, Cytosine and Uracil.

Question 25

What are proteins made of?

Answer 25

Hydrogen, Oxygen Carbon and Nitrogen.

Question 26

What are functions of proteins?

Answer 26

• Structural (e.g. keratin, callagin)
• Hormones (e.g. insulin, testosterone, oestrogen)
• Antibodies (e.g. produced by white blood cells)
• Receptor (e.g. usually found on the outside of cells cell membrane)
• Enzymes (e.g. amylase, lipase, pepsin)

Question 27

What are enzymes?

Answer 27

Proteins made by all living cells

Question 28

What are enzymes function as a biological catalyst?

Answer 28

To speed up a chemical reaction and are unchanged by the reaction and can be used again.

Question 29

What are examples of enzymes?

Answer 29

• Catalase breaking down hydrogen peroxide into water and oxygen
• Pepsin breaking down protein into amino acids
• Amylase breaking down starch into Maltose

Question 30

What can an enzyme only work on?

Answer 30

It’s specific substrate

Question 31

What is unique about the shape of an active site of an enzyme?

Answer 31

It is complementary to it’s specific substrate

Question 32

What is the 5 mark answer for give an account of the properties of enzymes?

Answer 32

• They are specific
• Active site
• Synthesis/Degradation reaction
• Unchanged and can be used again
• Optimum pH/ temp and can be denatured by too high temps and active site shape will no longer attach to substrate as changed shape.

Question 33

What are the five steps to genetic engineering?

Answer 33

1) Identify section of DNA that contains the required gene from the source chromosome.
2) Extract required gene using enzymes.
3) Extract plasmid from bacteria cell.
4) Insert required gene into bacterial plasmid using enzymes.
5) Insert plasmid into host bacterial cell to produce a genetically modified organism.

Question 34

What are uses of genetic engineering?

Answer 34

• Insulin for the control of diabetes
• Antibodies such as penicillin
• Growth hormone
• Various vaccines for the control of diseases

Question 35

What do cells need energy for?

Answer 35

• Cell division
• Protein synthesis
• Transmission of nerve impulses
• Muscle cell contraction

Question 36

What is respiration?

Answer 36

A chemical reaction that happens in all cells. It involves the release of the chemical energy stored in glucose through a series of enzyme-controlled reactions

Question 37

How is ATP energy created?

Answer 37

From the reaction of ADP + Pi

Question 38

What is the overall equation of aerobic respiration?

Answer 38

Glucose + Oxygen -> CO2 + Water + 38 ATP

Question 39

What does glucose split into in respiration?

Answer 39

2 Pyruvate + 2 ATP

Question 40

What does one pyruvate split into in respiration?

Answer 40

18 ATP + Water + CO2

Question 41

When does anaerobic respiration take place?

Answer 41

respiration when there is not enough oxygen. Is normally the result of muscle fatigue during excercise.

Question 42

What is the overall reaction of anaerobic respiration in animals?

Answer 42

Glucose -> 2 ATP + lactate

Question 43

What are the 2 pyruvate broken down into in anaerobic respiration and where does this take place?

Answer 43

Lactate which will turn into lactic acid and this happens in the cytoplasm.

Question 44

What is anaerobic respiration in plants also called?

Answer 44

Fermentation

Question 45

What is the overall reaction of fermentation in plants?

Answer 45

Glucose -> 2 ATP + ethanol + CO2

Question 46

What does the fact CO2 is released mean for the fermentation reaction?

Answer 46

It is irreversible

Question 47

What does the fact no CO2 is released mean for anaerobic respiration in animals?

Answer 47

The lactate can be removed by paying back the oxygen debt, meaning that it is reversible.

Question 48

What can fermentation be used for?

Answer 48

The production of bread, wine and beer.