B1. Cells and Movement of substances Flashcards

1
Q

How do you calculate total magnification

A

Total magnification = Eyepiece lens x objective lens

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2
Q

Define the term resolution

A

Resolution is the ability to distinguish between two separate points in an image

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3
Q

What is the function of the nucleus?

A

Contains DNA in the form of chromosomes. Contains the genetic code.

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4
Q

What is the function of the cytoplasm in a cell?

A

This is where chemical reactions take place

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5
Q

What is the function of the cell membrane?

A

Controls what enters and leaves the cells.

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6
Q

What is function of the mitochondria in cells?

A

This is the site of respiration. Glucose + Oxyen –> Carbon dioxide + water vapour + ATP energy

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7
Q

Define the word ‘magnification’

A

Magnification is how much bigger an image is compared to it’s actual size. Can be calculated by using the IAM triangle.

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8
Q

What is the function of the cellulose cell wall?

A

This is outer layer of plant cells. It is made of cellulose. It gives the plant strength and support.

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9
Q

Why are ribosomes needed in a cell?

A

Ribosomes are the site (location) where proteins are made.

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10
Q

What is the function of chloroplasts in plant cells?

A

Chloroplasts contain a green chemical called chlorophyll. It traps sunlight energy which is needed for photosynthesis.

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11
Q

What type of microscope could be used for viewing for small organelles e.g. ribosomes?

A

Electron microscope

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12
Q

What type of DNA do prokaryotic cells have?

A

1 circular chromosome, NOT enclosed by a nucleus.

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13
Q

What type of DNA do eukaryotic cells have?

A

Many linear chromosomes enclosed by a nucleus.

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14
Q

Define diffusion.

A

Diffusion is the net random movement of particles from an area of high concentration to an area of low concentration.

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15
Q

Define Osmosis

A

Osmosis is the net random movement of WATER from an area of high concentration to an area of low concentration, across an PARTIALLY PERMEABLE MEMBRANE.

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16
Q

What is meant by a passive process?

A

A passive process does not require ATP energy.

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17
Q

What is meant by an active process?

A

An active process requires ATP energy from respiration.

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18
Q

What happens to an animal cell when it is placed in a more DILUTE solution?

A

The cell gains water by osmosis and may burst. This is called lysis.

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19
Q

What happens to an animal cell when it is placed in a more CONCENTRATED solution?

A

The cell loses water by osmosis shrivels. This is called crenation.

20
Q

Define active transport

A

The movement of substances from an are of LOW concentration to an area of HIGH concentration across a partially permeable membrane. - ATP is needed and a carrier protein in the membrane.

21
Q

What happens to a plant cell when it is placed in a more DILUTE solution?

A

The cell gains water by osmosis but does not burst. This cell is now turgid.

22
Q

Why does a plant cell not burst when it is placed in a more dilute solution?

A

The plant cell has a cell wall.

23
Q

What happens to an plant cell when it is placed in a more CONCENTRATED solution?

A

The cell loses water by osmosis. The cell membrane pulls away from the cell wall. This is is called plasmolysis.

24
Q

Give an example of molecules that move by active transport.

A

Mineral ions in the soil are in low concentration. They enter the root hair cells via active transport.

25
Q

Where does ATP energy come from?

A

It is released during aerobic respiration in the mitochondria.

26
Q

How do you calculate % change in mass?

A

(Final mass - initial mass) ÷ (initial mass) x 100

27
Q

Which type of cells do NOT have a nucleus?

A

Prokaryotic cells

28
Q

How are sperm cells adapted for their function?

A

● Streamlined head and long tail to aid swimming. ● Many mitochondria (where respiration happens) which supply the energy to allow the cell to move. ● The acrosome (top of the head) has digestive enzymes which break down the outer layers of membrane of the egg cell.

29
Q

How are nerve cells adapted for their function?

A

● The axon is long, enabling the impulses to be carried along long distances ● Having lots of extensions from the cell body (called dendrites) means branched connections can form with other nerve cells ● The nerve endings have many mitochondria which supply the energy to make special transmitter chemicals called neurotransmitters. These allow the impulse to be passed from one cell to another.

30
Q

How are muscle cells adapted for their function?

A

● Special proteins slide over each other, causing the muscle to contract ● Lots of mitochondria to provide energy from respiration for contraction ● They can store a chemical called glycogen that is used in respiration by mitochondria.

31
Q

How are root hair cells adapted for their function?

A

● Have a large surface area due to root hairs, meaning more water can be absorbed by osmosis. ● The large permanent vacuole affects the speed of movement of water from the soil to the cell. ● Have mitochondria to provide energy from respiration for the active transport of mineral ions into the root hair cell.

32
Q

How are xylem cells adapted for their function?

A

● Xylem cells hollow and are joined end-to-end to form a continuous tube so water and mineral ions can move through. ● Lignin is deposited in spirals which helps the cell walls which help withstand the pressure from the movement of water.

33
Q

How are phloem cells adapted for their function?

A

● Cell walls of each phloem cell form structures called sieve plates when they break down, allowing the movement of substances from cell to cell. ● Have few organelles so food can move faster. ● Have a companion cell with mitochondria to supply energy.

34
Q

What is the function of sperm cells?

A

Sperm cells contain a nucleus with half the DNA (23 chromosomes). Sperm cells fertilise the egg cell during sexual reproduction.

35
Q

What is the function of nerve cells?

A

Transmits electrical impulses.

36
Q

What is the function of muscle cells?

A

Muscle cells are specialised to contract quickly to move bones or simply to squeeze therefore causing movement.

37
Q

What is the function of root hair cells in a plant?

A

They are specialised to absorb water by osmosis and mineral ions by active transport from the soil.

38
Q

What is the function of xylem cells in a plant?

A

They are specialised to transport water and mineral ions up the plant from the roots to the shoots.

39
Q

What is the function of phloem cells in a plant?

A

Transports food (by translocation) from the leaves to other parts of the plant.

40
Q

How do you convert mm to μm?

A

x1000

41
Q

Convert 35mm into μm

A

35mm x 1000 = 35,000μm

42
Q

Convert 4.7mm to μm

A

4.7 x 1000 = 4700μm

43
Q

What are the correct labels for the cell shown in the diagram?

A
44
Q

What are the labels A and B in the animal cell diagram?

A

A = Cell membrane

B = Nucleus

45
Q

List 2 differences between prokaryotic cells and eukaryotic cells.

A
  • Prokaryotic cells do not have a nucleus, eukaryotic cells do.
  • Prokaryotic cells do not have any membrane bound ribosomes, eukaryotic cells do.
  • Prokaryotic cells have smaller ribosomes to those in eukaryotic cells.