6.5 Reproductive Technologies Questions and Answers

6.5 Reproductive technologies – questions and answers

Q1.

Bk Ch6 S6.5 Q1

aDefine‘artificial insemination’ and ‘artificial pollination’.

bDescribe some of the advantages of artificial insemination and artificial pollination.

A1.

Bk Ch6 S6.5 A1

aArtificial insemination is the injection of male semen into a female of the same species – a technique often used by animal breeders. Artificial pollination is the dusting, often by hand, of fertile stigmas with the pollen from plants with desired characteristics.

bArtificial insemination allows farmers to mate animals with the most desirable characteristics even when large distances are involved. For example, sperm from a prize bull can be transported and used to inseminate a large number of cows in distant locations. This means a much larger number of offspring can be produced than occurs in normal mating. The same applies to artificial pollination of plants. Pollen from the male stamens is collected and used to dust the stigmas. Again, plants with the most desirable characteristics are selected for breeding in this way. Both techniques can result in rapid and widespread change within populations of organisms.

Q2.

Bk Ch6 S6.5 Q2

aWhat is a clone?

bUse a series of dot points to summarise the steps involved in cloning a sheep.

cExplain how all the sphagnum plants in an alpine valley might be clones (Hint: see Chapter 4).

A2.

Bk Ch6 S6.5 A2

aA clone is a genetically identical copy of an organism.

bCloning a sheep:

1. Mammary tissue from adult sheep is collected and cultured in the laboratory.

2. The nucleus is removed from a single mammary cell and transferred into an emptied mature egg cell.

3. The egg cell is then implanted into the uterus of a mature female sheep.

4. Normal development proceeds until a healthy lamb is born at the end of gestation.

cSphagnum moss usually reproduces asexually so all new plants that are produced from an original parent are clones. Given the right conditions of moisture and sunlight new plants easily grow from the smallest fragments of the adult plant. When fragments of branchlets break away from the parent plant and come to rest in a suitable place they will develop into new plants. In this way clones of sphagnum moss can come to inhabit an alpine valley.

Q3.

Bk Ch6 S6.5 Q3

Explain what is meant by a transgenic organism and give two examples explaining why each was produced.

A3.

Bk Ch6 S6.5 A3

A transgenic organism is one that has had a piece of DNA from another species inserted into its own DNA and is able to pass on the genetic modification to the next generation.

Any two examples plus the reason for their production; for example

•cotton bred with a bacterium included so it kills insect pests. The crops need not be sprayed with insecticide and are therefore cheaper to grow and less polluting to produce.

•bacteria containing human genes for the production of the human hormone insulin. The bacteria produce insulin which is harvested and used to treat people with diabetes.

Q4.

Bk Ch6 S6.5 Q4

Describe two processes used to produce transgenic species.

A4.

Bk Ch6 S6.5 A4

The answer given will depend on the two processes chosen but could include descriptions of isolating genes using restriction enzymes, making recombinant DNA, making copies of genes, or inserting genes into plants, animals or bacteria.

Q5.

Bk Ch6 S6.5 Q5

For a named plant and a named animal that have been selectively bred, explain the potential impact of the plant and animal on genetic diversity.

A5.

Bk Ch6 S6.5 A5

The answer given will depend on the example chosen but in general there should be some explanation about reducing the genetic diversity and consequences for the species over time such as inability to respond to environmental changes, pests and diseases and unsuitability to all geographic locations. If a domesticated plant or animal is chosen then human demands may determine the genetic characteristics selected.

6.5 Reproductive technologies – QApage 1 of 2