Biology S3 Revision 2017 Flashcards

1
Q

In an experiment how would you culture microbes?

A

In an experiment you would culture microbes by:

1) Setting up a bunsen burner on a heatproof mat.
2) Flaming an inoculating loop and cooling for a few seconds
3) Gently spreading some bacteria onto the agar .
4) Closing the lid on the petri dish
5) Flaming the inoculating loop again
6) Opening the petri dish again to place an antibiotic disk into the centre
7) Closing the dish and sellotape around the centre.
8) Labeling the petri dish and store upside down.

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2
Q

What is diffusion?

A

Diffusion is the random movement of a substance from a high area concentration to a low area concentration. e.g. oxygen diffuses from the blood into the cells.

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3
Q

What is osmosis?

A

Osmosis is the movement of water from a high area concentration to a low area concentration through a partially permeable membrane.

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4
Q

What are enzymes?

A

Enzymes are proteins which act to speed up chemical reactions. They are produced from glandular tissue which are found all over the body.

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5
Q

What does the digestive system do?

A

The digestive system supplies food to the body organs.

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6
Q

What does the digestive system consist of?

A

The digestive system consists of the mouth, the oesophagus, the stomach and the intestines.

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7
Q

What do Arteries contain?

A

Arteries contain:

High blood pressure

Blood flow rapid

Transports blood away from the heart

No semi- lunar valves

Tunica media thick and composed of elastic fibres and smooth muscle

Pressure of blood is high and pulsatile

Blood oxygenated except in pulmonary artery.

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8
Q

What do Capillaries contain?

A

Capillaries contain:

Low blood volume

Blood flow slowing

Link arteries to veins. Site of exchange of materials between blood and tissue.

No semi- lunar valves

No tunica media. Only tissue present is endothelium. No elastic fibres

Pressure of blood flowing and non- pulsatile

Mixed oxygenated and deoxygenated blood.

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9
Q

What do veins contain?

A

veins contain:

Increased blood volume

Blood flow slow

Transport blood towards the heart

Semi- lunar valves to intervals along the length to prevent back flow of blood.

Pressure of blood and non- pulsatile

Tunica media relatively thin and only slightly muscular. Few elastic fibres.

Blood deoxygenated except in pulmonary vein.

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10
Q

What are stomata?

A

Stomata are the holes mainly located on the underside of the leaves which allow gases to enter and leave the leaf.

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11
Q

Where does diffusion take place?

A

Diffusion takes place when water and minerals move from a high concentration to a low concentration in the spongy mesophyll.

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12
Q

What do the palisade cells contain?

A

The palisade cells contain chloroplasts to carry out photosynthesis.

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13
Q

What to the upper epidermal cells produce?

A

The upper epidermal cells produce cuticle to prevent damage from parasites and herbivores.

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14
Q

What is cambium?

A

Cambium is unspecialised meristem cells located between the phloem and the xylem.

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15
Q

What is translocation?

A

Translocation is the movement of soluble organic compounds to where they are required.

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16
Q

What is transpiration?

A

Transpiration is the process where plants absorb water in the roots and it’s drawn up through the xylem and then it is given off as water vapour through pores in the leaves.

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17
Q

What is the body’s first line of defence and what does it act as?

A

The body’s first line of defence is the skin. It acts as a barrier to protect microbes from entering our body.

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18
Q

What do bacteria produce making us feel ill?

A

Bacteria produce toxins which affect our bodies, making us feel ill.

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19
Q

How do virus reproduce?

A

Viruses reproduce using our cells.

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20
Q

What do white blood cells do?

A

White blood cells:

Produce antibodies

Produce antitoxins

Engulf and digest foreign cells.

Produce memory cells.

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21
Q

What happens if the skin is broken?

A

If the skin is broken scabs form from platelets to close the entry point.

22
Q

What happens when pathogens or foreign matter enter the body?

A

If pathogens or foreign matter enter the body or bloodstream the white blood cells help to defend the body.

23
Q

What are capillaries?

A
  1. Capillaries are the smallest of the body’s blood vessels. 2. They are only one cell thick. 3. They are where the transfer of oxygen and other nutrients, from the bloodstream to other tissues in the body, takes place. 4. They also collect carbon dioxide waste materials and fluids for return to the veins.
24
Q

What is the maximum temperature that micro-oganisms should be grown at?

A

The maximum temperature that micro-oganisms should be grown in a lab is 25°C or under. A temperature above 25°C shouldn’t be used because harmful microbes can grow which can cause disease.

25
Q

What three ways can you make sure an experiment testing the effect of antibiotics on bacteria has not been contaminated?

A

1) The petri dishes and culture medium must be sterilised before use to kill any unwanted micro- organisms. 2) If an inoculating loop is used to transfer the bacteria to the culture medium, it should be sterilised first by passing it through a hot flame. 3) After transferring the bacteria the lead of the petri dish should be lightly taped on to stop the micro-organisms and air getting in.

26
Q

Name two ways that embryonic stem cells can be used to cure diseases.

A

Embryonic stem cells could be used to replace faulty cells in sick people - they could make insulin-producing cells for people with diabetes or nerve cells for people paralysed with spinal injuries.

27
Q

Why are some people opposed to the use of embryonic stem cells?

A

Some people are opposed to the use of embryonic stem cells because they feel embryos shouldn’t be used for experiments since each one is a potential human life.

28
Q

Tell me four facts about chromosomes.

A

1) Chromosomes are found within the cell nucleus. 2) Chromosomes are made from DNA. 3) Human body cells contain 46 chromosomes. 4) Human gametes contain 23 chromosomes.

29
Q

What is active transport?

A

This is when a substance moves from a low to a high concentration using energy.

30
Q

Why do alveoli need thin walls?

A

Because it gives a short distance to diffuse.

A good blood supply- Gives a short distance to diffuse.

Elastic fibres in the walls- Allow stretch and recoil during breathing.

Moist walls- Allows gases to dissolve and diffuse faster.

Be in large numbers- Provides a large surface area for digestion.

31
Q

What is the villi’s function?

A

The villi’s function is to absorb digested food.

32
Q

What is the villi’s special features?

A

Lots of them to give a large surface area.

Good blood supply.

Microvilli on the surface.

They have lots of mitochondria for active transport.

33
Q

What is the concentration?

A

The amount of particles in a specific area.

34
Q

What is the partially permeable membrane?

A

A barrier that only allows some particles to pass through.

35
Q

What does the xylem do?

A

The xylem transports water and minerals.

36
Q

What does the phloem do?

A

The phloem transports sugar (from photosynthesis) up and down through living cells.

37
Q

What are xylem?

A

Xylem are hollow dead cells (like straw)

38
Q

What does the skeletal system do?

A

The skeletal system protects, support and aids movement.

39
Q

What does the muscular system do?

A

The muscular system contracts and relaxes.

40
Q

What does the respiratory system do?

A

The respiratory system = O2 in and CO2 out of the body.

02= inhaling

C02= exhaling ( unwanted gases).

41
Q

What are the organs involved?

A

The organs involved are:

The Nosal cavity.

Right lung

Bronchus

Trachea

Left lung

Larynx

Pharynx

Diaphragm

42
Q

What is the circulatory system?

A

The circulatory system transports material around the body. It consists of the heart, networks of blood vessels and blood.

43
Q

What is the order of the digestive system?

A

Oesophagus

Liver

Stomach

Gall bladder

Pancreas

Colon

Appendix

Small intestine

Rectrum

44
Q

What does the endocrine system (hormones) do?

A

The endocrine system regulates many body processes. It consists of glands that make up hormones.

Pancreas

Thynoid gland

45
Q

What doe the nervous system consist of?

A

Brain

Spinal cord

Intercostal nerves.

46
Q

What does the excretory system do?

A

The excretory system removes waste from the body. It consists of urinary tract and kidneys.

47
Q

What does the reproductive system do?

A

The reproductive system enables us to produce children. Male and female system are different.

48
Q

What is a catalyst?

A

A catalyst is any substance that works to accelerate a chemical reaction without itself being used up.
It can be organic, synthetic or metal.

49
Q

What does temperature do in rates of reactions?

A

Temperature affects the rate of reaction.

50
Q

What is the active site in rates of reaction?

A

The active site is the part of the enzyme that forms a substrate during a chemical reaction.

51
Q

Where do you find enzymes in the body?

A

You find enzymes in the small intestines, stomach, mouth.