B3

Question 1

What’s the nucleus’s function?

Answer 1

Contains genetic material which controls cell activity.

Question 2

What’s the cytoplasm’s function?

Answer 2

Most chemical reactions take place here. These are controlled by enzymes.

Question 3

What’s the cell membrane’s function?

Answer 3

Controls the movement of substances to and from the cell.

Question 4

What’s the mitochondria’s function?

Answer 4

Release energy (most from respiration).

Question 5

What’s the ribosomes’s function?

Answer 5

To do protein synthesis.

Question 6

How many chromosomes does a human cell contain?

Answer 6

23 PAIRS.

Question 7

What does a chromosome carry?

Answer 7

Genetic material (genes).

Question 8

What does a nucleus contain?

Answer 8

DNA in the form of X and Y chromosomes.

Question 9

What do genes control?

Answer 9

A characteristic or feature.

Question 10

What is a gene?

Answer 10

A short strand of DNA.

Question 11

What does DNA form?

Answer 11

A double helix.

Question 12

What are different versions of the same gene called?

Answer 12

Alleles.

Question 13

Order in size of a cell’s genetic order:

Answer 13

cell’s nucleus> X and Y chromosomes> Genes >DNA> double helix> base pairs> triplets.

Question 14

How do you get a triplet?

Answer 14

A sequence of three base pairs.

Question 15

What does a triplet do?

Answer 15

A triplet codes for one amino acid.

Question 16

What do amino acids do?

Answer 16

A strand of sequenced amino acids make a specific protein.

Question 17

What are the complementary base pairs?

Answer 17

A-T and C-G.

Question 18

What is meant by complementary base pairs?

Answer 18

when two un-joined bases join together with their missing puzzle piece. Only two sets of complementary base pairs : A-T AND C-G.

Question 19

What’s the sequence of DNA replication?

Answer 19

1) Double strand ‘unzips’. 2) Free bases join to EXPOSED bases. 3)=complementary base pairs 4)2x new IDENTICAL strands are formed.

Question 20

State 2x reasons why you need to make proteins in your cells:

Answer 20

1) Reproduction/cloning/cell division 2)Regrowth in the cell

Question 21

Describe how DNA carries the genetic code:

Answer 21

DNA carries the genetic code in the double helix which is made out of phosphate (the backbone). In-between the back bone there are the base pairs which code (a triplet) for amino acids which in turn code ( in a sequence) for a particular protein.

Question 22

Explain how cell activity is controlled by the genetic code:

Answer 22

The genetic code is instructions for the cell: Base pairs in threes (a triplet) make a particular amino acid and then in turn the amino acids are sequenced for a particular protein for a particular function.

Question 23

Why is the shape of a protein molecule important?

Answer 23

The protein eg: enzyme has to fit the substrate exactly to for fill it’s function of a biological catalyst to a chemical reaction (a catalase). The reaction is the binding

Question 24

What is the active site?

Answer 24

Active site: The stage when the enzyme joins on to the substrate to catalyse the reaction.

Question 25

What are the uses of proteins?x4

Answer 25

1) Hormones eg;insulin 2)Carrier molecules eg; haemoglobin 3)structural proteins eg;collagen 4)enzymes eg; Amylase

Question 26

Biological catalysts are...? What do they do? Also how can you enhance their performance?

Answer 26

Enzymes. They speed up the chemical reaction (r of r) without being used up. You can increase the temperature but not too high otherwise the enzymes will become denatured and change their shape so they wouldn't fit the substrate.

Question 27

Chemical reactions are...?

Answer 27

The splitting or joining of a substrate.

Question 28

The substrate has to...?

Answer 28

Fit into the active site of the enzyme.

Question 29

Explain the 'lock and key' theory:

Answer 29

'lock and key' theory is that the specific enzyme has to receive the 'key' which is the substrate to catalyse the reaction.

Question 30

What does increasing the temperature do for the enzymes?

Answer 30

1) At first an increasing temperature increases the rate of reaction because the enzymes and the substrates have more k.e. which lowers the collision rate.

Question 31

What's the Q10 calculation?

Answer 31

rate at highest temp/rate at lowest temp

Question 32

What is a mutation?

Answer 32

A change in the genetic code/DNA

Question 33

What could happen if a mutation occurred in an unborn child?

Answer 33

1)Develop abnormally 2)Die

Question 34

How do you get cancer?

Answer 34

When mutant cells reproduce uncontrollably =tumor

Question 35

What's a neutral mutation?

Answer 35

1)Tongue rolling 2)Ear lobes

Question 36

What can cause mutations?

Answer 36

1) Ionising radiation eg: exposure to lots of radiation. 2) Exposure to harmful chemicals eg: Cigarettes. Carcinogen- if produces cancer. Mutagen- if produces mutations.

Question 37

What is anaerobic respiration?+ equation

Answer 37

Anaerobic respiration is when oxygen from the lungs is transported the cells by ATP(CONTROLLED BY ENZYMES)muscle's mitochondria where the chemical reaction of respiration happens. glucose → lactic acid (+ energy released)

Question 38

What's rate of reaction affected by?

Answer 38

Because ATP is controlled by enzymes the rate of reaction is affected by pH and temperature(denaturing changes shape of enzymes so the become obsolete from their previous function).

Question 39

What is anaerobic respiration?+equation

Answer 39

Anaerobic respiration doesn't use oxygen because there isn't enough oxygen to go around your body. Glucose→lactic acid+energy Lactic acid causes cramps and fatigue in muscles as it builds up.

Question 40

What's the respiratory quotient?

Answer 40

amount CO2 produced RQ------------------------ amount of O2 used

Question 41

How do you clone an adult animal?

Answer 41

Eg: Dolly 1)Take one sheep's cell and remove the nucleus. Leaving the egg cell with no genetic information. 2)Insert another nucleus from a different sheep in the empty cell. This was a diploid nucleus from an udder cell=all genetic information. 3)Electric shock given to the cell to start mitosis division. 4)the dividing cell is now an embryo and implanted in the surrogate sheep.

Question 42

What is mitosis?

Answer 42

Mitosis is the splitting of the cell into two identical cells.

Question 43

What's the process of mitosis?

Answer 43

1)Replicate DNA. PROPHASE 2)Coil into double arm chromosomes.METAPHASE 3)line up in the centre of the cell and two arms split to go at opposite ends of the pole/cell. METAPHASE 4) Spindle fibres grab them. ANAPHASE 5)Split and the new cell nuclear membrane is forming.TELOPHASE 6) Cells continue to grow. INTERPHASE

Question 44

What's the sequence of mitosis?

Answer 44

Prophase, metaphase, anaphase, telophase, interphase P mati