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Flashcards in Unit 1 Deck (16)
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How do magnification and resolution compare between electron and light microscopes. (1)

Resolution is higher on electron microscopes and magnification is higher on electron microscopes


How can you produce an accurate and useful scientific drawing from a microscope (2)

Use a pencil with a sharp point, label the diagram, use all the space and use clear unbroken Lines


Picture a graph that flattens out of the top showing growth of bacteria. Suggest one factor that might be limiting the population after 14 hours. (1)

Amount of nutrients


A student prepared uncontaminated cultures of the bacteria on Agar plates. Why was it important that the cultures we're not contaminated? (1)

It could have affected the results of the experiment


Suggest three things a student could do while preparing Agar plates to prevent contamination of cultures. (3)

Sterilise equipment in a flame
Store the cultures upside-down
Sellotape the edges of the petri dish to stop bacteria getting in


Describe three benefits of producing cloned plants from stem cells (3)

It is cheap and fast, it can help save endangered species, desirable features can be reproduced


Therapeutic cloning whilst creating an embryo, from which the stem cells for treatment of sourced. For this reason some people are against using therapeutic cloning. Discuss the ethical issues surrounding the use of embryonic stem cells in medicine and research. (4)

Some people feel that embryonic stem cells from human embryos shouldn't be used for experiments as embryo potential human life.
Some people may argue there are other sources of stem cells that scientists could use, embryos to create stem cells is unjustified.
Some people think that using embryonic stem cells to cure patients already exists in the other suffering is more important than the rights of embryos.
Some people argue that many embryonic stem cells sourced from unwanted embryos from fertility clinics, which would probably be destroyed anyway


State two factors other than concentration gradient that affect the rate of diffusion into a cell. (2)

Surface area.
Diffusion distance.


Explain why it is important that all potato pieces from an experiment to come from the same potato.(1)

Different potatoes have different water concentrations.


Describe the structure and function of the root hair cell in a plant. Include details of how the structure of the root hair cell helps it to carry out its function.(3)

The function of root hair cells to take up substances from the soil.
Root hair cells have elongated hairs that stick out into the soil.
This has give the route a large surface area for absorbing substances.


Give four features of an effective gas exchange surface in an animal. (4)

Good ventilation.
Large surface area.
Efficient blood supply.
Thin membrane.


State which feature of the lungs gives them a short diffusion pathway. (1)

Alveoli walls are thin.


State which feature of the lungs gives them a large surface area. (1)

Lots of alveoli.


Describe and explain how the structure of the small intestine is adapted for absorbing the products of digestion. (6)

The small intestine is covered in villi which increases the surface area for absorption.
There is a good blood supply which maintains the concentration gradient so absorption can happen quickly.
Villi I have a single layer of surface cells which gives a short diffusion pathway


Describe the movement of gases into and out of the leaf.(3)

Carbon dioxide diffuse to the leaf.
Water vapour diffuses out the leaf.
Oxygen diffuses out the leaf


Suggest the purpose of the air spaces in the leaf. (1)

They increase the surface area for carbon dioxide to diffuse into cells