Genetics

Question 1

The structure of DNA.

Answer 1

Double helix

• Base (hydrogen bonded); Adenine, Thymine, Guanine and Cytosine
• Phosphate
• Deoxyribose Sugar

Question 2

What are the nucleotides?

Answer 2

• Phosphate
• Deoxyribose sugar
• Nitrogen base

Question 3

What forms the upright parts of the double helix ladder?

Answer 3

Alternating sugar and phosphate units.

Question 4

What does DNA stand for?

Answer 4

Dexoyribose Nucleic Acid.

Question 5

What is genetics?

Answer 5

The study of heredity.

Question 6

What is heredity?

Answer 6

The passing of traits from parents to offspring.

Question 7

What do genes make?

Answer 7

Protein.

Question 8

What are true breeding plants?

Answer 8

Plants that always create plants that look like themselves.

Question 9

What is a hybrid?

Answer 9

The offspring of two plants of animals of different species or varieties.

Question 10

What is genetic manipulation?

Answer 10

The process of gene splicing to create recombinant DNA and enables cells to be genetically modified.

Question 11

What are the 7 steps of genetic manipulation?

Answer 11

1. Plasmids are removed from the bacterium
2. The plasmids are cut using an enzyme
3. DNA is removed from the cell
4. DNA is cut to isolate the gene using an enzyme
5. The gene is inserted into plasmid to form recombinant DNA
6. The recombinant is put into a bacterium
7. The bacterial calls grow and divide to produce many copies of the introduced gene

Question 12

What are enzymes?

Answer 12

A protein manufactured by a cell and is a catalyst in various biological functions.

Question 13

Define recombinant DNA.

Answer 13

DNA which has been modified by adding DNA from another source.

Question 14

Define DNA ligase.

Answer 14

An enzyme which joins DNA strands together.

Question 15

What are restriction enzymes?

Answer 15

An enzyme produced by certain bacteria.

Question 16

What is the restriction site?

Answer 16

Where the DNA has been cut.

Question 17

What is plasmid?

Answer 17

The ring of DNA found in bacteria.

Question 18

What is the donor DNA?

Answer 18

An organism which supplies living tissue to another organism.

Question 19

What is gene therapy?

Answer 19

When the defective gene is replaced with a normal gene.

Question 20

What is gene testing?

Answer 20

Replacing genes with diseases for normal genes to prevent or cure a disease.

Question 21

What are chromosomes?

Answer 21

Thread-like structures in the nucleus, composed of DNA and proteins; contains the genetic information in the form of genes.

Question 22

What is a gene?

Answer 22

A section of DNA the carries the genetic information for a particular characteristic.

Question 23

What is an allele?

Answer 23

Alleles are different forms of the same gene.

Question 24

Mendal’s 1st law

Answer 24

• Alleles are inherited as one from each parent.
• In the heterozygous state, the dominant trait is expressed phenotypically, the recessive trait is passed from carrier to offspring genotypically

Question 25

Dominant genes/characteristics

Answer 25

The characteristic that is expressed in the heterozygous.

Question 26

Recessive genes/characteristics

Answer 26

The characteristic the remains hidden in the heterozygous condition.

Question 27

Mendal’s 2nd law

Answer 27

Different gene pairs assort independently in gamete formation (meiosis) - this is only true in some cases

Question 28

Modes of Inheritance

Answer 28

• Inheritance patterns describe how a disease is transmitted in families.
• Help to predict the recurrence risk for relatives.
• Inheritance patterns for single gene disorders are classified based on whether they are autosomal or X-linked and whether they have a dominant or recessive pattern of inheritance.

Question 29

What is an autosome?

Answer 29

All the chromosomes in a cell other than the sex cell chromosomes.

Question 30

Sex linked characteristics

Answer 30

Sex linkage is linked to the gender of the individual. Usually such genes are found on the X chromosome.

Question 31

What is a punnett square?

Answer 31

The Punnett square is a diagram that is used to predict an outcome of a particular cross or breeding experiment.

Question 32

Define homozygous

Answer 32

Having two identical alleles on homologous chromosomes.

Question 33

Define heterozygous

Answer 33

Having two different alleles on homologous chromosomes.

Question 34

What are homologous chromosomes?

Answer 34

Chromosomes with genes for particular characteristics at the same location.

Question 35

What is a geneotype?

Answer 35

The genetic information carried by an individual.

Question 36

What is a phenotype?

Answer 36

The observable of the individual; the way genotype is expressed.

Question 37

What is a pedigree?

Answer 37

A diagrammed family history which gives information on the mode of inheritance of a disease and the recurrence risk, that is, the probability that the offspring of a couple will express a genetic disease.

Question 38

What is the diploid number?

Answer 38

The number of chromosomes in body cells; two sets or 2N.

Question 39

What is meosis?

Answer 39

The cell division which only produces gametes, the number of chromosomes in cells after meosis is half compared to the original cell.

Question 40

What is mitosis?

Answer 40

The cell division which is for growth and repair of an organism.

Question 41

Where are chromosomes found?

Answer 41

In the nucleus in most of the cells of your body.