Prelim Revision

Question 1

What is a unicellular organism?

Answer 1

An organism with one single cell

Question 2

What is a multicellular organism?

Answer 2

An organism made up of many cells

Question 3

What does the nucleus do?

Answer 3

Controls cell activities and contains genetic material (DNA)

Question 4

What does the cell membrane do? What is it made of?

Answer 4

Controls what enters and exits the cell, made of phospholipids and plasmids, selectively permeable

Question 5

What does the cell wall do?

Answer 5

Support and shape, prevents plant cells from bursting

Question 6

What is the cell wall made of? (plant and other cells)

Answer 6

Cellulose in plant cells, other substances in other cells like fungal and bacterial

Question 7

What does the vacuole do?

Answer 7

Stores the cell sap, helps to support the cell

Question 8

What do chloroplasts do?

Answer 8

Contains chlorophyll, site of photosynthesis

Question 9

What do mitochondria do?

Answer 9

Site of aerobic respiration, and ATP production

Question 10

What to ribosomes do?

Answer 10

Site of protein synthesis

Question 11

What is every living organism made of?

Answer 11

Cells (unicellular or multicellular)

Question 12

What do animal cells contain?

Answer 12

Cell membrane, cytoplasm, nucleus, ribosome, mitochondria

Question 13

What do plant cells contain?

Answer 13

Cell wall, cell membrane, nucleus, cytoplasm, vacuole, ribosomes, mitochondria, chloroplasts (in green plant cells)

Question 14

What do fungal cells contain?

Answer 14

Cell wall, cell membrane, vacuole, nucleus, ribosomes, mitochondria, cytoplasm

Question 15

What do bacterial cells contain?

Answer 15

Plasmid, cell membrane, cytoplasm, cell wall, ribosome

Question 16

What is aerobic respiration?

Answer 16

The release of energy from food by a cell using oxygen

Question 17

What is the cytoplasm?

Answer 17

Site of chemical reactions

Question 18

What is DNA?

Answer 18

Substance found in chromosomes that carries the genetic code

Question 19

What is photosynthesis?

Answer 19

Process carried out by green plants to make their own food using light energy

Question 20

What is the cell membrane made of?

Answer 20

Phospholipids and protein

Question 21

What is passive transport?

Answer 21

The movement of molecules from a high concentration to a low concentration, does not require additional energy

Question 22

What are some examples of passive transport?

Answer 22

Diffusion and osmosis

Question 23

What is diffusion?

Answer 23

The movement of substances from a high concentration to a lower concentration

Question 24

What are some examples of substances that enter most cells by diffusion?

Answer 24

Oxygen, glucose, amino acids

Question 25

What are some examples of substances that leave most cells by diffusion?

Answer 25

Carbon dioxide, Urea

Question 26

Why is diffusion important?

Answer 26

Helps provide the cell with raw materials and helps to remove waste products

Question 27

What is osmosis?

Answer 27

The movement of water molecules from a region of high water concentration to a region of low water concentration

Question 28

What would happen to an animal cell placed in a solution with a higher water concentration than that inside the cell?

Answer 28

Burst

Question 29

What would happen to an animal cell placed in a solution with a lower water concentration than that inside the cell?

Answer 29

Shrink

Question 30

What would happen to a plant cell placed in a solution with a higher water concentration than that inside the cell?

Answer 30

Turgid

Question 31

What would happen to a plant cell placed in a solution with a lower water concentration than that inside the cell?

Answer 31

Plasmolysed

Question 32

What is active transport?

Answer 32

The movement of molecules from a region of low concentration to a higher concentration, requiring additional energy (ATP)

Question 33

What is the chromosome complement of a cell?

Answer 33

The number and type of chromosomes it contains

Question 34

What would it mean if the chromosome complement was diploid?

Answer 34

That their nuclei have two matching sets of chromosomes

Question 35

What is replication?

Answer 35

The process by which DNA copies itself

Question 36

What is a replicated chromosome called?

Answer 36

A chromatid

Question 37

What happens during mitosis?

Answer 37

Each chromosome is replicated, the nucleus of a diploid parent cell divides to produce two daughter cells (genetically identical to the parent calls)

Question 38

What is the sequence of events during mitosis?

Answer 38

1. Chromosomes replicate and become visible as pairs of chromatids 2. The chromosomes line up along the equator of the cell 3. Their chromatids are pulled to opposite poles by spindle fibres to form two new nuclei 4. The cell cytoplasm then splits between the new nuclei to form two daughter cells

Question 39

What are chromosomes made up of?

Answer 39

Genes

Question 40

What is a single DNA molecule called?

Answer 40

A double stranded helix

Question 41

What does each strand of DNA carry?

Answer 41

A chain of molecules called bases

Question 42

What are the four different types of bases?

Answer 42

Adenine, Thymine, Guanine, and Cytosine, these bases make up the genetic code

Question 43

What does the base sequence of a specific gene determine?

Answer 43

The amino acid sequence in the specific protein to be assembled

Question 44

Where are proteins assembled?

Answer 44

At the ribosomes in the cell cytoplasm

Question 45

What is messenger RNA (mRNA)?

Answer 45

A molecule that carries a complementary copy of the code from the DNA in the nucleus to a ribosome

Question 46

What does the shape of a protein affect?

Answer 46

The function

Question 47

What are the functions of proteins?

Answer 47

Structural, Enzymes, Hormones, Antibodies and Receptors

Question 48

What do structural proteins do?

Answer 48

Make up cell structures such as membranes

Question 49

What do enzymes do?

Answer 49

Function as biological catalysts and are made up by all living cells, they speed up chemical reactions and are unchanged in the process

Question 50

What do hormones do?

Answer 50

Act as chemical messengers between cells and travel in body fluids such as blood

Question 51

What are antibodies?

Answer 51

Protein molecules that are involved in body defences

Question 52

What are receptors?

Answer 52

Found in cell membranes, recognise specific substances

Question 53

What is the substance an enzyme acts on called?

Answer 53

The substrate

Question 54

What is the active site of an enzyme?

Answer 54

Where they bind to substrate molecules

Question 55

What does it mean that enzymes are specific?

Answer 55

The shape of the active site only fits with the shape of the complementary substrate, lock and key

Question 56

What conditions does an enzyme work best in?

Answer 56

Optimum

Question 57

What can extremes in temperature or pH do to the enzyme? How will this affect the enzyme?

Answer 57

Change its molecular shape, known as denaturation, this will affect the rate of the reaction

Question 58

How can genetic information be transferred?

Answer 58

Naturally or Artificially

Question 59

What are some natural methods of genetic transfer?

Answer 59

Fertilisation in plants and animals