Genetics

Question 1

What does DNA stand for

Answer 1

Deoxyribonucleic acid

Question 2

What are nucleotides

Answer 2

Phosphate
Deoxyribose sugar
Nitrogen rich bases

Question 3

What is the shape of DNA

Answer 3

Double helix, like a twisted ladder: the uprights of the ladder are phosphate and sugar, and the rungs are bases

Question 4

What are the four bases

Answer 4

Adenine
Thymine
Guanine
Cytosine

Question 5

Describe complementary base pairing

Answer 5

The chemical structure of the rich bases means that they can only form chemical bonds with one of the other bases
A pairs with T
C pairs with G

Question 6

Define allele

Answer 6

Different forms of the same gene

Question 7

Define dominant

Answer 7

The characteristic that is a expressed in the heterozygous condition. To be observed in the appearance of the individual

Question 8

Define genotype

Answer 8

Genetic information carried by an individual

Question 9

Heterozygous

Answer 9

Having two different alleles on a homologous structure

Question 10

Homozygous

Answer 10

Having two identical alleles on homozygous structure

Question 11

Mutation

Answer 11

A mistake that happens as DNA is copied, causing a change to the base sequence

Question 12

Phenotype

Answer 12

Observable characteristics of the individual

Question 13

Pure breeding

Answer 13

Where all individuals have the same genetic information fir a chat geriatric generation after generation

Question 14

Recessive

Answer 14

The characteristic that remains hidden in the heterozygous structure

Question 15

Gene

Answer 15

A section of DNA that carries the genetic code for a particular characteristic

Question 16

Autosomes

Answer 16

All the chromosomes in a cell other than the sex chromosomes

Question 17

Centromere

Answer 17

The point on the chromosome, where two chromosomes are joined together

Question 18

Chromatid

Answer 18

One of the strands of chromosomes following replication

Question 19

Diploid number

Answer 19

The number of chromosomes in body cells: 2 sets

Question 20

Haploid

Answer 20

The number of chromosomes in gametes: one set

Question 21

Homologous structure

Answer 21

Chromosomes with genes for particular characteristics at the same location

Question 22

Give 3 examples of facts about chromosomes

Answer 22

Long thin thread like structured, found in the nucleus of the cell
Chromosomes are made of DNA and protein

Question 23

Steps in genetic manipulation (7)

Answer 23

1. Plasmids are removed from a bacterium
2. Plasmids are cut using an enzyme (restriction enzyme)
3. DNA is removed from human cells
4. DNA is cut using an enzyme to isolate the gene
5. Human gene is inserted into the plasmid to form recombinant DNA
6. The recombinant DNA is put into a bacterium
7. Bacterial cells grow and divide to produce many copies of the introduced gene

Question 24

How many cells in the human body

Answer 24

46 chromosomes (in 23 pairs)

Question 25

How many chromosomes in gametes

Answer 25

23 chromosomes, one in each pair

Question 26

Plasmids

Answer 26

Ring if DNA found in bacteria

Question 27

What did Mendel test his experiments with

Answer 27

Pea plants

Question 28

What is the purpose of Punnett squares

Answer 28

To determine and predict specific characteristics of an offspring when two parents mix

Question 29

Sex linked inheritance

Answer 29

There are some conditions, eg colourblindness, that are sex inherited. This means the genes involved are on sex determining chromosomes.

Question 30

Chromosomes for a female

Answer 30

XX

Question 31

Chromosomes for male

Answer 31

XY

Question 32

Steps of meiosis (6)

Answer 32

1. Pairs of double stranded chromosomes line up | 2. One double stranded chromos

Question 33

Describe mitosis

Answer 33

Mitosis produces two daughter cells that are identical to the parent cell. This type of cell division is involved in growth and repair of the body.

Question 34

Describe meiosis

Answer 34

Mitosis produces gametes (eggs and sperm) that have half the number of chromosomes as the parent cell

Question 35

Steps of mitosis, include PMAT

Answer 35

Prophase: chromosomes are replicated to become double stranded, and then they become visible. Metaphase: double stranded chromosomes line up along the equator (middle) of the cell Anaphase: the chromosomes move to oppose ends of the cell Telophase: two nuclei form, each with the diploid number of chromosomes. The membranes also form separating the nuclei into two daughter cells

Question 36

Steps of meiosis, include PMAT

Answer 36

Prophase 1: chromosomes line up with homologous pairs Metaphase 1: pairs of double stranded chromosomes line up Anaphase 1: one double stranded chromosomes of each pair moves to each pole Telophase 1: two cells are formed Prophase 2: Metaphase 2: double stranded chromosomes line up Anaphase 2: chromatids separate and move to poles Telophase 2: four cells result with a haploid number of chromosomes