Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biology > Structure and functions in living organisms > Flashcards

Structure and functions in living organisms Flashcards

1
Q

What is the role of the nucleus?

A

-controls the activities of the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the cytoplasm?

A
  • a jelly-like fluid that fills the cell.

- It is where most of the cell’s chemical reactions take place.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the cell membrane?

A
  • surrounds the cells, a thin layer on the surface
  • forms a boundary between the cytoplasm and the outside
  • partially permeable =selectively permeable
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the cell wall?

A
  • found outside the cell membrane

- made of cellulose (in plants)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are mitochondria?

A 
- site of aerobic respiration in eukaryotic cells.
Aerobic respiration (process which uses sugar and oxygen to release energy) releases energy in the mitochondria.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are chloroplasts?

A

-absorb light energy and make food via photosynthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are ribosomes?

A

-organelles that are responsible for synthesising (making) proteins.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the vacuole?

A

-filled with cell sap(storage area)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Where are Eukaryotic cells found and how big are they?

A
  • plants, animals, fungi and protoctists (single-celled organisms that don’t fit other categories).
  • 10-100 micro meters in size.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Give an example of a Prokaryote.

A

-bacteria, they are multi cellular

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What parts of cells do plants have that animals don’t?

A

-vacuole, chloroplasts, cell wall (made of cellulose)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the cell wall in fungi made of?

A

-chitin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How do fungi feed?

A

-secreting digestive enzymes and absorbing broken down decaying matter), and often store carbohydrates as glycogen.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Is fungi uni or multi cellular?

A

-both

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are enzymes?

A

-biological catalysts; they speed up lots of the reactions that happen in cells, such as those involved in respiration.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is tissue?

A

-groups of similar cells that act together to perform a similar function.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is epithelial tissue?

A

-lines the stomach.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is muscular tissue?

A
  • tissue that can contract to bring about force and motion.

- moves the contents of the stomach around during digestion.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the function of glandular tissue?

A

-produces digestive juices that break down the stomach’s contents.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What does the liver produce?

A

-bile

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What do glands produce?

A

-Glands (e.g. pancreas and salivary glands) produce digestive juices.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the role of the small intestine?

A

-digests food and absorbs soluble (can be dissolved) food molecules.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the role of the large intestine?

A

-absorbs water molecules from the remaining undigested food. This allows it to produce faeces.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is a permanent vacuole?

A
  • found in plants
  • a fluid-filled sac that stores water.
  • It is enclosed in a membrane
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What allows a sperm cell to penetrate an egg cell?

A

-acrosome at the tip of the head contains

digestive enzymes needed to penetrate (break into) an egg cell.

26
Q

What is an axon?

A
  • part of the cell where electrical signals travel along

- nerve cells have long axons

27
Q

What is the substance that strengthens the cells walls of xylem cells?

A

-lignin

28
Q

What are the steps for a light microscope experiment?

A
  • Put a thin sample of tissue (e.g. onion epidermis) onto a microscope slide
  • Add a few drops of a suitable stain
  • Place a coverslip on top of the tissue and place the slide onto the microscope stage.
  • Use the objective lens with the lowest magnification, and focus on the sample.
  • Increase the magnification and refocus to see different features of the cell.
29
Q

Define diffusion.

A
  • the net movement of particles from an area of high concentration to an area of lower concentration.
  • Substances can move in and out of cells across cell membranes via diffusion
30
Q

What factors affect the rate of diffusion? (4)

A
  • The higher the temperature, the faster the rate of diffusion.
  • The greater the distance a substance has to diffuse across, the more time taken.
  • the bigger the difference in concentration between two areas, the greater the concentration gradient and the faster the rate of diffusion
  • The larger the surface area of the membrane that a substance is diffusing through (e.g. the membrane around a cell), the faster the rate of diffusion.
31
Q

What is the formula for volume to surface area ratio?

A

-Surface area to volume ratio = surface area ÷ volume

32
Q

Define osmosis.

A

-the diffusion of water across a partially permeable membrane from a dilute solution (high concentration of water) to a concentrated solution (low concentration of water).

33
Q

What is an experiment for osmosis?

A
  • Cut discs of raw potato and measure their mass.
  • Put discs in different concentrations of sugar or salt solution.
  • After 30 minutes, measure the mass of each disc again.
34
Q

Formula for calculating % change in mass

A

(final mass-initial mass)/initial mass x 100

35
Q

What does active transport do in humans?

A
  • allows sugar molecules, which are needed for cell respiration, to be absorbed into the blood from the gut
  • there is a lower concentration of sugar molecules in the lumen compared to the cell
36
Q

What does active transport in the root hair cell in a plant do?

A
  • allows plants to absorb mineral ions, which are necessary for healthy growth
  • there is a lower concentration of mineral ions in the soil compared to the cell
37
Q

What is active transport?

A

-moves substances from a more dilute solution to a more concentrated solution (against a concentration gradient)

38
Q

What does active transport require and how does it get it?

A
  • energy from respiration

- from the mitochondria in the cell

39
Q

What is passive transport?

A
  • diffusion and osmosis

- means they don’t require energy

40
Q

What features make the lungs a good exchange service?

A
  • large surface area to volume ratio
  • there is a small diffusion difference
  • they have a steep concentration gradient because the lungs have a good blood supply and are well ventilated.
41
Q

What are lipids and what are they made up of?

A
  • fats and oils, make up cell membranes
  • made up of carbon hydrogen and oxygen
  • made up of fatty acids and glycerol
42
Q

What are Carbohydrates made of and what are they used for?

A
  • carbon, hydrogen and oxygen

- stored as energy

43
Q

What are proteins made up of and what do they do?

A
  • carbon, hydrogen, oxygen, nitrogen, sulfur
  • amino acids
  • give structural support and may have important roles in chemical reactions
44
Q

Which 2 types of proteins have active sites?

A
  • antibodies and enzymes

- these are areas of the protein that have to be a specific shape for the protein to function properly.

45
Q

How do you test for starch in a leaf?

A
  • add iodine solution.

- It will turn blue-black if starch is present.

46
Q

How do you test for lipids?

A
  • add ethanol and water and shake.

- If lipids are present, a white emulsion (cloudy liquid) will form.

47
Q

How do you test for glucose?

A
  • add Benedict’s reagent and heat for about two minutes.
  • It will turn any of green, yellow or red if sugar is present.
  • The colour depends on the concentration.
48
Q

How do you test for proteins?

A
  • add Biuret solution.

- It will turn mauve or purple if proteins are present.

49
Q

What is the function of enzymes?

A

-speed up a reaction, known as a biological catalyst

50
Q

How does temp affect rate of enzyme action?

A
  • increasing temp initially speeds up action
  • Enzymes have an optimum temperature. Once this temperature is reached, the activity decreases.
  • Past a certain temperature, the active site changes shape, and the enzyme is denatured (loses its catalytic activity).
51
Q

How does pH affect rate of enzyme action?

A
  • have an optimum pH (measure of acidity).
  • If the pH changes away from the optimum pH, then the enzyme activity decreases.
  • If the pH is too low or too high, then the enzyme is denatured and will not function.
52
Q

What does amylase do?

A

-an enzyme that breaks down starch

53
Q

How does light intensity affect the rate of photosynthesis?

A
  • more energy is provided.
  • if the light intensity is increased above a certain threshold, the rate of photosynthesis will not increase because another factor (such as temperature) is limiting the rate of the reaction.
54
Q

What factors affect the rate of photosynthesis?

A
  • light intensity
  • carbon dioxide concentration
  • chlorophyll concentration
  • temperature (until 45)
55
Q

How do you test the rate of photosynthesis?

A
  • using pondweed and a lamp
  • change the distance between the lamp and the pondweed and count the number of bubbles produced.
  • In this experiment, light intensity is the independent variable and the number of bubbles is the dependent variable.
56
Q

When testing for stored starch in leaves, why are they first soaked in ethanol?

A
  • removes the chlorophyll from leaves, turning them white.

- This makes it easy to see which parts of the leaf turn dark blue when iodine is added.

57
Q

What is the difference between accuracy, reliability, and validity?

A
  • accuracy=how close a measured value is to its true value.
  • reliability=the ability of an experiment to produce consistent results.
  • validity=how appropriate an experimental method is at achieving the aim of an experiment
58
Q

How can you increase reliability?

A

-repeat experiment

59
Q

What is the role of the waxy cuticle?

A

-covers the upper and lower epidermis and creates a water proof barrier over the surface of the leaf, reducing water loss

60
Q

What is the role of the guard cells?

A

-in the lower epidermis of the leaf, close in certain conditions to reduce water los

61
Q

Visking tubing experiment for osmosis.

A
  • fix some visking tubing over the end of a thistle funnel
  • pour sugar solution down the glass tube into the thistle funnel
  • put thistle funnel into glass beaker of water, measure where sugar solution comes up to on the glass tube
  • leave overnight and measure where the water level is

Biology (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions