Biology-2014

Question 1

How does decay keep eggs warm?

Answer 1

Microorganisms respire releasing energy

Question 2

Why must birds control the temperature of their nest?

Answer 2

Maintains sex balance

Question 3

What does a vaccine contain?

Answer 3

Inactive pathogens

Question 4

How does a vaccination prevent infection

Answer 4

White blood cells produce antibodies rapidly which kill pathogens

Question 5

Why can’t antibodies treat measles

Answer 5

Because measles live inside the cell and antibiotics can’t kill viruses

Question 6

Why don’t overused antibiotics work

Answer 6

Because pathogens develop resistance

Question 7

Describe a reflex action

Answer 7

A stimuli is detected by the receptors (eyes, skin, etc). This triggers chemical impulses to travel up the sensory neurone to the CNS. There is a synapse where chemicals transmit the impulse across the gap. A relay neurone will then pass the impulse on quickly. This stimulates the motor neurone to send the chemical impulses to the effector (ie muscles or glands)

Question 8

What was thalidomide originally created to treat

Answer 8

Poor sleeping

Question 9

What was thalidomide found to be useful for

Answer 9

Morning sickness

Question 10

What was the problem with thalidomide

Answer 10

Babies were born with limb abnormalities

Question 11

What makes someone dependent on a drug

Answer 11

Changes in chemical processes

Question 12

What’s Darwins theory of evolution (in relation to elephants)

Answer 12

Variation caused longer nosed individuals to get more food these survivors breed more passing on genes for a longer nose

Question 13

What’s Lamarcks theory

Answer 13

If an animal stretched their nose in order to reach food, that stretched nose would be passed on to their offspring

Question 14

Why were people not sure about evolution

Answer 14

Insufficient evidence and the mechanism of inheritance wasn’t known

Question 15

Describe how a student should prepare an uncontaminated culture of the bacterium in the Petri dish

Answer 15

• Petri dish and agar must be sterilised to kill unwanted bacteria
• swab must be passed through a flame to make it sterile
• swab is used to spread bacterium onto agar
• the lid of Petri dish opened as little as possible to prevent microbes from air entering
• it must then be sealed with tape to prevent microbes from air entering to allow growth of bacteria

Question 16

How does energy decrease as it is passed through organisms

Answer 16

There is less loss in respiration and there are fewer stages of transfers