Marcus' bio review

Unit 1

Why do you think biologists originally placed fungi within the plant kingdom? [K/U T/I]

Predict how the level of atmospheric oxygen would change if the population of photosynthetic

marine bacteria greatly increased. Explain your prediction. (2.1) T/I A

Explain how vaccines have helped in the ght against many of the world’s most devastating

diseases.

(2.2) T/I A

Unit 2

Can a couple in which both partners are heterozygous for cystic brosis conceive a child without

the disease? What is the probability that they will do so? (5.5) T/I A

Most cattle raised for beef are fed a diet based on corn. The digestive system of cattle is better

able to deal with grass and other leafy plants, but corn is much cheaper. Feeding corn to cattle

keeps the price of beef lower. Unfortunately, because of their digestive systems, cattle must be

fed antibiotics along with corn so that they gain weight quickly enough to be profitable, and so

they do not get sick or die. Beef NEL Unit 2 Review 273 7380_Ch06_pp226-275.indd 273

1/10/11 8:43:09 AM cattle also often live in very densely packed feedlots, which adds to the

possibility of infection. In 2010, there were more than 5 million beef cattle in Canada. Most of

those were fed corn and given antibiotics. T/I A

(a) Are you concerned that such widespread use of antibiotics could contribute to antibiotic

resistance? Why or why not?

(b) If beef cattle are fed grass instead of corn, they often require fewer antibiotics to stay

healthy. But it is also more expensive to feed them, and they may not grow as fast. As a result,

cattle ranchers have to charge more for their product, and beef costs more for the consumer. Do

you fear the potential for antibiotic resistance more than a shortage of affordable beef? Explain.

(c) Horizontal gene transfer between strains of bacteria known in beef cattle and harmful strains

known in humans may be possible. Does that knowledge change your response to (b)? Explain

why or why not.

. Genetic engineers may eventually be able to change the inherited traits of human embryos. T/I

A

(a) In what circumstances, if any, do you think you would allow your child’s inherited traits to be

changed in this way?

(b) Would you have wanted your parents to allow your own traits to be changed in this way?

Explain why or why not.

Unit 3

As a scientist, why is it important to consider alternative explanations that might account for

your findings when you test hypotheses? (7.4) K/U

There are approximately 100 remaining Florida panthers in the Everglades. Florida panthers

are a subspecies of mountain lions. Would bringing mountain lions into the Everglades from the

Rockies help or hurt the Florida panther gene pool? Support your opinion. (7.6) T/I A

. How large a role do you think humans have had in the current rapid rate of extinctions on

Earth? K/U A

Unit 4

During a heart transplant, a heart can be taken out of a person’s body and continue to beat on

its own. How is this possible? Explain what keeps the heart beating even though it receives no

input from the nervous system. (11.4) K/U T/I

. Could life forms on a distant planet develop a metabolic process in which food was broken

down to release energy without involving oxygen? Explain your thinking. (10.1) T/I A

. A friend received a fairly deep cut on her leg in a soccer game. The cut now has pus forming

around it. Is the presence of pus a positive sign that the wound is healing correctly or a sign of

infection? Why? (11.2) T/I A

Unit 5

Suppose your neighbour weeds his lawn regularly, but the dandelions keep reappearing.

Explain why this is happening and suggest what your neighbour should do to stop the

dandelions from regrowing. (13.2) K/U A

Some substances produced by plants can be used in harmful ways by humans. For example,

the nicotine in tobacco leaves is part of cigarettes and other tobacco products that harm human

health. Imagine that a group of concerned individuals has proposed eradicating all plants that

produce substances that can be used in harmful ways by humans. Do you think this is a

reasonable solution? Explain why or why not. (12.2) T/I C A

. Do you think city planners should be required to include trees in their plans for cities? State at

least two specific reasons to support your response. (12.7) K/U A