what's in cells? Flashcards

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1
Q

What are the two most fundamental groups of cells?

A

Prokaryotic cell

Eukaryotic cell

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2
Q

Types of cells?

A

Eukaryotic
Plants, animals, fungi, protists
10 - 100 µm

Prokaryotic
Bacteria
0.1 - 5.0 µm

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3
Q

What sub-cellular structures (structures inside the cell) are found in all eukaryotic cells?

A
  • cytoplasm
  • nucleus
  • cell membrane
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4
Q

Eukaryotic cells can be up to 1,000 times larger than ________ cells.

A

Prokaryotic

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5
Q

Which sub-cellular structures (structures inside the cell) can be found in prokaryotic cells?

A
  • cell membrane
  • plasmids
  • single DNA loop
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6
Q

_______ cells are 10 - 100 micrometres in size.

A
  • Eukaryotic
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7
Q

What is true of eukaryotic cells?

A
  • Found in protists

- 10-100 micrometers in size

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8
Q

An animal cell contains?

A
  • Mitochondria
  • Cytoplasm
  • Partially permeable cytoplasm
  • Ribosomes
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9
Q

Definition and function of:

Nucleus

A
  • The control centre of the cell

- Contains the genetic material in the form of chromosomes.

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10
Q

Definition and function of:

Cell membrane

A

Separates the interior of the cell from the environment outside. It is selectively permeable (it can control substances moving in and out of the cell).

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11
Q

Definition and function of:

Cytoplasm

A

A jelly-like fluid that fills the cell. It is where most of the cell’s chemical reactions take place.

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12
Q

Definition and function of:

Mitochondria

A

Aerobic respiration (process which uses sugar and oxygen to release energy) releases energy in this part of the cell.

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13
Q

Definition and function of:

Ribosomes

A

Responsible for synthesising (making) proteins.

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14
Q

In addition to the sub-cellular structures found in animal cells, plant cells contain:

A
  • Chloroplasts
  • Cell wall
  • Large permanent vacuole
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15
Q

Many _____ cells keep their ability to differentiate throughout their lives, so they are always able to create new tissues. Adult ______ cells usually only divide to repair existing tissues.

A

1) . plant

2) . animal

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16
Q

Plant cells:

A
  • retain the ability to differentiate
  • can be reproduced by cuttings
  • regularly create new tissues
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17
Q

Animal cells:

A
  • Have to reproduce sexually
  • differentiate in the embryo
  • rarely create new tissues
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18
Q

A cell wall is made of cellulose, which increases the structural ______ of the cell.

A
  • strength
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19
Q

Components of bacterial cells

A
  • plasmids
  • cytoplasm
  • cell wall
  • cell membrane
  • flagella
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20
Q

As well as the structures found in all prokaryotic cells, some bacteria also have _______. These are whip-like structures that are used for movement.

A
  • flagella
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21
Q

Cell differentiation is rare in mature animals. Their cells mostly divide to replace cells and repair damaged _____.

A
  • tissues
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22
Q

Cell differentiation primarily happens:

A
  • in human embryos

- in plants throughout their lives

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23
Q

Digestive enzymes are found at the tip of the head of sperm cells in the _______. The enzymes help penetrate the egg cell.

A
  • acrosomes
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24
Q

sperm cell: head

A
  • Contains the sperm cell’s nucleus, which carries one half of an organism’s genetic material. It also contains an enzyme needed to penetrate (break into) an egg cell.
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25
Q

sperm cell: middle section

A

-Is filled with mitochondria to provide energy for the sperm to travel a long distance to reach the egg.

26
Q

sperm cell: Flagellum

A

This is used for the cell’s motion.

27
Q

How are nerve cells adapted to their role?

A
  • dendrites
  • myelin sheath
  • long axon
28
Q

Nerve cells are specialised to transmit messages around the body. What kind of signals do nerve cells transmit?

A

-eletrical

29
Q

Which of the following are the adaptations of muscle cells?

A
  • protien fibres

- lots of mitochondria

30
Q

Muscle cells contain lots of ________, which allow them to release lots of energy. ______ fibres within the cell can contract, allowing the muscle to move.

A
  • mitochondria

- Protein

31
Q

How is the root hair cell adapted to its function?

A
  • long projections

- no chloroplasts

32
Q

The two types of cell that transport food and water are:

A
  • xylem

- phloem

33
Q

Phloem transports food products to parts of the plant where they are needed. Phloem vessels are made up of columns of ______ cells. The end walls of phloem cells contain small _____ to allow food products to move up and down the phloem vessels.

A
  • living

- holes

34
Q

_____ cells are specialised to increase the efficiency of ______ absorption and the uptake of minerals required for the plant’s survival.

A
  • root hair cells

- water

35
Q

what is true of the phloem vessels in plants?

A
  • made of living cells

- transports food products

36
Q

Magnification equation?

A

Magnification = Image size ÷ Actual size

37
Q

A cell has a diameter of 0.001cm. An image of the cell viewed through the microscope has a diameter of 5 cm. The magnification is hence 5 cm/0.001 cm = x_____
.

A

x5000

38
Q

A cell has a diameter of 0.002cm. An image of the cell viewed through the microscope has a diameter of 6 cm. What is the magnification?

A

x3000

39
Q

What is the maximum resolution and magnification that an electron microscope can achieve?

A
  • Magnification of x500,000

- resolution of 1nm

40
Q

Types of Microscopes?

A

Light Microscope

  • First used in the 16th century
  • Resolution better than the human eye
  • Allowed scientists to see bacteria for the first time

Electron Microscope

  • First used in 1933
  • Resolution of 1nm and achieved x500,000 magnification
  • Allowed scientists to see sub-cellular structures more clearly
41
Q

Light Microscope Experiment

A

1) . Put a thin sample of tissue (e.g. onion epidermis) onto a microscope slide.
2) . Add a few drops of a suitable stain/dye (e.g. iodine).
3) . Place a coverslip on top of the tissue and place the slide onto the microscope stage.
4) . Use the objective lens with the lowest magnification, and focus on the sample.
5) . Increase the magnification and refocus to see different features of the cell.

42
Q

When using a light microscope, use the _____ power ______ lens, and focus on the sample. Increase the power and then refocus.

A

1) . lowest

2) . objective

43
Q

Which microscope enabled us to understand the functions of sub-cellular structures?

A

electron microscope

44
Q

What’s a variable?

A

A variable is an object, event, idea, feeling, time period, or any other type of category you are trying to measure. There are two types of variables-independent and dependent.

45
Q

What’s an independent variable?

A

An independent variable is exactly what it sounds like. It is a variable that stands alone and isn’t changed by the other variables you are trying to measure. For example, someone’s age might be an independent variable. Other factors (such as what they eat, how much they go to school, how much television they watch) aren’t going to change a person’s age. In fact, when you are looking for some kind of relationship between variables you are trying to see if the independent variable causes some kind of change in the other variables, or dependent variables.

46
Q

What’s a dependent variable?

A

Just like an independent variable, a dependent variable is exactly what it sounds like. It is something that depends on other factors. For example, a test score could be a dependent variable because it could change depending on several factors such as how much you studied, how much sleep you got the night before you took the test, or even how hungry you were when you took it. Usually when you are looking for a relationship between two things you are trying to find out what makes the dependent variable change the way it does.

47
Q

Potential sources of contamination are:

A

1) . Skin
2) . Air
3) . Soil
4) . Water

48
Q

Cultures of microorganisms (microorganisms grown in a lab) can be used to investigate the effects of _______ and disinfectants, which both kill bacteria.

A
  • antibiotics
49
Q

What are the two mediums used to culture bacteria

A

Agar gel plate

Nutrient broth

50
Q

Aseptic technique is used to prevent contamination. What does it involve?

A

Temperature

Flames

Boiling

Using Lids

51
Q

The Cell Cycle

A

1) . Initial growth
2) . Mitosis
3) . Cell division

52
Q

Stem cells are undifferentiated cells found in:

A

Embryos

Plant meristems

Bone marrow

53
Q

Disadvantages of Stem Cells

A

Raise ethical concerns

Transfer viral infections

54
Q

Therapeutic cloning

A

Therapeutic cloning is a process that produces an embryo with the same genes as the patient. Stem cells taken from this embryo will have the same DNA as the patient, so the patient’s body will not reject the stem cells or body cells made from the stem cells.

55
Q

Diffusion

A

Diffusion is the random movement of particles through a gas or liquid from high concentration to a low concentration.

56
Q

Factors affecting the rate of diffusion:

A

temperature

concentration gradient

membrane surface area

57
Q

In osmosis, water will move from a solution with a ______ concentration of water to a solution with a low concentration of water.

A

high

58
Q

Water will move across the membrane from a dilute solution (with lots of water molecules) to a _____ concentrated solution (fewer water molecules).

A

more

59
Q

Name the substances that are absorbed via active transport in the following structures:

A

Minerals
Roots of plants

Sugar
Guts of humans

60
Q

The three main forms of transport in cells are:

A

osmosis

diffusion

active transport

61
Q

Active Transport

A

This is the net movement of particles against a concentration gradient, and so energy is required.

62
Q

Passive transport is..

A

Passive transport is a naturally occurring phenomenon and does not require the cell to expend energy to accomplish the movement.