EQ's Flashcards
Describe how light enters the eye
[4 marks]
The cornea is curved and transparent. It refacts light, which then travels through the pupil, and focuses it onto the lens
The lens then refracts the lightand focuses is onto the retina
Explain how the eye responds to dim light
[3 marks]
The light detectors in the retina (cones and rods) detect the dim light levels
This triggers the reflex arc and electrical impulses are transmitted along neurones
Causing the circular muscle in the iris to relax an the radial muscle in the iris to contract.
This makes the pupil dilated so that a larger volume of light can enter the eye
Lily struggles to read small text in a book when it is close to her face.
Explain what can you conclude about her vision and the structure of her eyes.
[3 marks]
She has hyperopia (lonsightedness)
Means lenses in her eye are too long and thin.
Therefore, they cannot refract light enough, so image is brought into focus behind the retina
Or her eyeballs are too short
so her lenses are too close to the retina.
This means the image is brought into focus behind the retina
Give two ways in which students could improve their investigation on reaction time
[2 marks]
- Repeat the investigation more
- Perform the investigation on several other people
What effect does drinking coffee have on reaction time?
[1 mark]
Caffeine speeds up reaction time
Describe the difference between the function of a receptor and the funtion of an effector.
[4 marks]
A receptor (e.g pain receptors in skin) detect a stimulus which generates elecrtical impulses
An effector (e.g. muscles in arms) convert an impulse into a response action
Give two control variables in the reaction time practical
[2 marks]
- Drop ruler from the same height
- Use the same/dominant hand
Which of the following are examples of reflex actions?
- Jumping in the air to catch a ball
- Raising a hand to protect eyes from bright light
- Releasing saliva when food enters mouth
- Running away from danger
- Withdrawing hand from sharp object
[2 marks]
- Releasing saliva when food enters mouth
- Withdrawing hand from sharp object
They are UNCONSIOUS actions!!!
Alcohol dilates blood vessels in the skin.
Suggest why it is dangerous to drink alcohol between going from hot sauna to a cold swimming pool
[4 marks]
Blood vessel dilation (vasodilation) allows more blood to flow through the capillaries close to the surface of the skin.
This causes heat to be transferred to the surroundings, decreasing body temperature.
If you get too cold, this can lead to hypothermia which is very dangerous
A healthy person without diabetes is given a sugary drink. Their blood glucose levels are monitored and plotted on a graph. The same person is then later given bread. Their blood glucose levels are monitored and put on the same graph to compare to the levels when they drank the sugary drink.
Explain why the blood glucose levels would rise at a slower rate after eating the bread
[3 marks]
Bread contains starch
Starch/Carbohydrates are broken down into glucose by enzymes
This process takes time to release the glucose
So the blood glucose levels rise at a slower rate
During _ _ _ _ _ _ _, reproductive hormones cause secondary sex characteristics to develop
Fill in the blank
Puberty
During puberty, reproductive hormones cause _ _ _ _ _ _ ** ** _ _ characteristics to develop
Fill in the blank
During puberty, hormones cause secondary sex characteristics to develop
Give three examples of secondary sex characteristics
Pubic hair
Wide hips
Breasts
What is the female reproductive hormone?
Oestrogen
Which gland secretes oestrogen?
Ovaries
