National 5 unit 1 - S3

Question 1

Names of organelles in a plant cell:

Answer 1

Cytoplasm
Mitochondria
Cell membrane
Nucleus
Ribosomes

Question 2

Names of organelles in a plant cell:

Answer 2

Cell wall
Cytoplasm
Mitochondria
Cell membrane
Vacuole
Chloroplasts
Ribosomes
Nucleus

Question 3

Function of Nucleus:

Answer 3

Contains cell DNA and the cells activities

Question 4

Function of Ribosomes:

Answer 4

Used for protein synthesis

Question 5

Function of mitochondria:

Answer 5

Site of respiration

Question 6

Function of chloroplasts:

Answer 6

Site of photosynthesis

Question 7

Function of cytoplasm:

Answer 7

Site of chemical reactions

Question 8

Function of vacuole:

Answer 8

Stores cell sales and water

Question 9

Function of cell membrane

Answer 9

Controls the entry and exit of materials in a cell

Question 10

Function of cell wall:

Answer 10

To support the cell and give it structure

Question 11

What is the cell membrane made up of?

Answer 11

Phospholipids and proteins

Question 12

What is the cell wall made up?

Answer 12

Cellulose

Question 13

What is osmosis?

Answer 13

When water particles move down the concentration gradient from low to high through a selectively permeable membrane until evenly spread- this takes no energy

Question 14

Define turgid

Answer 14

Swelled up and firm but not bursting

Question 15

Define plasmolysed

Answer 15

To become shrivelled and lost moisture

Question 16

Define flaccid

Answer 16

When the whole tissue has lost water

Question 17

Define active transport

Answer 17

When solid or gas particles move up the concentration gradient from low to high until evenly spread this takes energy

Question 18

Define diffusion

Answer 18

When solid or gas particles move down the concentration gradient from high to low until evenly spread - this takes no energy

Question 19

Define genes

Answer 19

Sub units of chromosomes

Question 20

Define chromosomes

Answer 20

Threadlike structures found in the nucleus

Question 21

How many chromosomes do humans have?

Answer 21

46

Question 22

What is the structure of DNA called?

Answer 22

A double helix

Question 23

What are the 4 different bases of DNA?

Answer 23

A (adenine)
T (thymine)
C (cystosine)
G (guanine)

Question 24

What are DNA strands held together by?

Answer 24

Weak hydrogen bonds

Question 25

What does the A base bond with?

Answer 25

T base

Question 26

What does C base bond with?

Answer 26

G base

Question 27

What does the base sequence in DNA code for?

Answer 27

Amino acid sequences in proteins

Question 28

How many bases code for 1 amino acid?

Answer 28

3 bases

Question 29

What are amino acids held together by?

Answer 29

Peptide bonds

Question 30

What are the first 3 steps in protein synthesis?

Answer 30

1. The DNA opens up 2. mRNA (messenger RNA) is made in the nucleus against one of the dna strands (it is a copy) 3. The mRNA passes out of the nucleus into the cytoplasm

Question 31

What are the last 2 steps in protein synthesis?

Answer 31

4. When the mRNA meets a ribosome the sequence of bases code for different amino acids 5. These amino acids are joined together by peptide bonds to form a protein

Question 32

Define genetic engineering:

Answer 32

The transfer of genes from on organism to another e.g. humans to bacteria

Question 33

What are the first 2 stages of genetic engineering?

Answer 33

1.the required gene is identified and this chromosome is cut by special enzymes to release the gene 2. A plasmid is taken from a bacterial cell and cut open using special enzymes which act like scissors

Question 34

What is a plasmid?

Answer 34

A bacterial genome

Question 35

What are the last three stages of genetic engineering?

Answer 35

3.the chromosome is sealed into the plasmid using a different enzyme which acts like glue 4. The plasmid is inserted into a host bacterial cell 5. The bacteria with this gene then starts to multiply

Question 36

Define vector:

Answer 36

Something that acts as a carrier between species

Question 37

What acts as the vector in genetic engineering?

Answer 37

The bacterial plasmid