Unit A Section 4.2

Question 1

What is artificial selection?

Answer 1

Artificial selection is the process of selecting and breeding individuals with desirable traits to produce offspring that have these desired traits

Question 2

What is the difference between natural selection and artificial selection?

Answer 2

-in natural selection the environment “selects”
traits.
-In artificial selection, humans select traits.

Question 3

What organisms can artificial selection apply to?

Answer 3

livestock, champion horses, domestic pets, food, and ornamental plants.

Question 4

How can food or plants be artificially selected?

Answer 4

-by taking the seeds of the healthiest or best
producing plants and sowing them the following year, farmers can generally “weed out” less desirable traits and promote more desirable ones.

Question 5

How long has an artificial selection going on?

Answer 5

-Humans have practiced artificial selection since we first began to farm about 10 000 years ago.
- After so many generations of artificial selection,
most of our plants no longer resemble the wild species from which they were bred

-For example, Corn was bred by native peoples from a species of grass called teosinte

Question 6

What is biotechnology?

Answer 6

using technology to biologically breed animals into more desired ones

Question 7

What is the advantage of biotechnology?

Answer 7

artificial selection has successfully produced most of our world’s crops and livestock

Question 8

What is the disadvantage of biotechnology?

Answer 8

it takes a very long time (many generations of plants and animals) to get an organism with the desired combination of traits.
-EX. breed cows over many generations to get a whole herd that produces large quantities of milk

Question 9

What is the solution for the slow artificial selection process?

Answer 9

• developed technologies that can speed up this process

- These technologies can range from “low tech” to extremely “high tech.”

Question 10

What is a clone?

Answer 10

Identical organisms produced by technology are called clones

Question 11

What is the simplest way to create a clone?

plants

Answer 11

is by taking a cutting from a plant and growing an
identical plant from the cutting.

-Horticulturalists do this routinely.

Question 12

What is the drawback of cloning?

plants

Answer 12

the ideal plant has only so many leaves that can be

cut off to use as cuttings.

Question 13

What is the solution for the drawback of cloning plants,.

HOW have Scientists have developed a quicker way to create clones

Answer 13

• Cells are removed from an individual plant that has the particular traits that are wanted
• These cells are placed on a Petri dish or bottle containing nutrients and hormones the cells need.
• Once these cells have developed into seedlings, they can be transplanted into the soil.

Because the starting point is a cell rather than an entire part of the plant, many more clones can be produced from a single plant

Question 14

What Artificial reproductive technology?

Answer 14

refers to any artificial method of joining a male and female gamete.

Question 15

What is artificial insemination?

Answer 15

In artificial insemination, sperm are harvested from a bull with desired characteristics and are inserted into many female cows.

-In artificial insemination, sperm from just a few animals
are used to impregnate many females.

Question 16

What is the advantage of artificial insemination?

Answer 16

is that the bull’s sperm can be in several places at

once and more cows can be inseminated

Question 17

What is vitro fertilization?

Answer 17

• Another reproductive technology is in vitro fertilization
• In this technology, sperm from a prize bull and eggs from a prize cow are harvested from the animals
• In a laboratory, the eggs and sperm are placed in a Petri dish, and the eggs are fertilized.
• This produces many more embryos than could be produced naturally.
• Each embryo is implanted into a different cow.
• These cows will eventually give birth to many calves, all of which will be brothers and sisters.

Question 18

What is the advantage of vitro fertilization?

Answer 18

-Scientists can also determine the sex of the embryos before they are implanted into a cow to develop

-By choosing only female embryos, dairy farmers can therefore be guaranteed that all their calves will be
female, rather than having to use their resources to raise unneeded males.

Question 19

what is Genetic engineering?

Answer 19

refers to any technology that directly alters the
DNA of an organism

-every new advance increases our ability to control the
characteristics of organisms.

Question 20

What are the genetic engineering techniques?

Answer 20

-genetic engineering techniques involve inserting a
gene from one species into another species.
-Ex. Bacteria are genetically engineered to produce life-saving medicines such as insulin
-Scientists have isolated the gene that contains the instructions for making Bt toxin and have inserted it into the DNA of plants.

Question 21

How do artificial technologies risk animals?

Answer 21

-Artificial reproductive technologies can reduce the genetic variation in breeding lines of livestock.

Question 22

Why are some animals cloned?

Answer 22

-the rhesus monkey ANDi have been genetically altered as part of research programs into human diseases
-cattle, are being cloned as potential largescale producers of meat and milk
- Herds of such genetically identical individuals may be far more susceptible to disease than more genetically
variable herds.

Question 23

What is the drawback for animal cloning?

Answer 23

-unsuccessful pregnancies, birth defects, and deaths among clones.

-Some researchers speculate that something about the process of removing the nucleus from the donor egg
may be responsible

Question 24

What is the problem with genetically engineering plants to be herbicide resistant?

Answer 24

• Many crop plants can still cross with their wild weed relatives.
• There have been reported cases of genetically engineered canola interbreeding with weeds, and the weeds’ offspring have become resistant to herbicide.