Cells, Tissues And Organs Flashcards
(88 cards)
0
Q
How can you see cells?
A
Using a microscope
1
Q
What have all living things got in common?
A
They are all made up of cells
2
Q
What does the nucleus do?
A
It controls all the activities of the cell. It contains the genes on the chromosomes. They carry the instructions for making new cells or new organisms.
3
Q
What is the cytoplasm?
A
A liquid gel in which most of the chemical reactions needed for life take place.
4
Q
What’s the function of the cell membrane?
A
Controls the passage of substances into and out of the cell.
5
Q
What’s the function of mitochondria?
A
Structure in the cytoplasm where oxygen is used and most of the energy is released during respiration.
6
Q
What’s the function of ribosomes?
A
Where protein synthesis takes place. All the proteins needed in the cell are made here.
7
Q
What structures are in an animal cell?
A
Nucleus Cytoplasm Cell membrane Mitochondria Ribosomes
8
Q
What structures are found in plant cells?
A
Nucleus Cytoplasm Cell membrane Cell wall Ribosomes Mitochondria Vacuole Chloroplasts
9
Q
What’s the function of a cell wall?
A
Made of cellulose and strengthens the cell and gives it support.
10
Q
What’s the function of chloroplasts?
A
They contain the green substance called chlorophyll , this absorbs light energy to make good by photosynthesis.
11
Q
Why don’t root cells have chloroplasts?
A
Because they’re underground and do not photosynthesise.
12
Q
How do plant cells differ from animal cells?
A
They have a cell wall, chloroplasts and a permanent vacuole.
13
Q
Why are the nucleus and the mitochondria so important in all cells?
A
The nucleus controls all the activities of the cell and contains the instructions for making new cells or new organisms. Mitochondria are the sit of aerobic respiration so they produce energy for the cell.
14
Q
What are bacteria?
A
Single celled living organisms that are much smaller than animal and plant cells.
15
Q
What structures are found in a bacteria cell?
A
Genetic material Cytoplasm Cell membrane Slime capsule Cell wall Plasmids Flagella
16
Q
Where is the genetic information found in the cell and in what form in bacteria?
A
Not in a nucleus , it’s found in a long strand of DNA freely in the cytoplasm.
17
Q
What are plasmids?
A
Extra circles of DNA found in the bacterial cytoplasm.
18
Q
What are flagella and what do they do?
A
It’s a long protein that lashes about, these bacteria use their flagella to move themselves around.
19
Q
What do yeast cells contain?
A
Nucleus
Cytoplasm
Membrane
Cell wall
20
Q
What’s the main way in which yeast cells reproduce and what does this involve?
A
Asexual reproduction
Involves a new yeast cell growing from the original cell to form a separate yeast organism.
21
Q
How do yeast cells differ from bacterial cells?
A
Bigger and have a nucleus
22
Q
What is the anaerobic respiration of yeast often called?
A
Fermentation
23
Q
During aerobic respiration and anaerobic respiration yeast cells break down sugar and what does it produce during the process?
A
Aerobic- water and carbon dioxide
Anaerobic- ethanol and carbon dioxide
24
What does it mean when a cell is specialised?
It's structure is adapted to suit the particular job it does.
25
What happens if you eat more food than you need?
Your body makes fat and stores it in fat cells
26
What are the three main adaptations of a fat cell?
1. They have a small amount of cytoplasm and large amounts of fat.
2. They have few mitochondria as the cell needs very little energy
3. They can expand- a fat cell can end up 1000 times it's original size as it fills up fat.
27
Where are are cone cells?
In the light-sensitive layer of your eye(retina).
28
What do cone cells do?
Make it possible for you to see in colour.
29
What are the three main adaptations of cone cells?
1. The outer segment contains a special chemical which changes in coloured light, it needs energy to change it back to its original form.
2. The middle part is packed full of mitochondria which releases the energy needed to reform the visual pigment and lets you see in colour.
3. The end part is a synapse that connects to the optic nerve.
30
What do root hair cells do?
Take up water more efficiently.
31
Where are the root hair cells closest to and what does this tissue do?
Closest to the xylem tissue which carries water and mineral ions up into the rest of the plant.
32
What are the two main adaptions of root hair cells?
1. Root hair cells increase the surface area for water to move into the cell.
2. They have a large permanent vacuole that speeds up the mom pavement of water by osmosis from the soil across the root hair cell.
33
What are the main adaptations that sperm cells have to reach the egg?
1. Long tail whips side to side to help the sperm move towards the egg
2. The middle section is full of mitochondria which provides energy for the tail to work.
3. The acrosome stores digestive enzymes for breaking down the outer layers of the egg
4. A large nucleus contains genetic information to be passed on.
34
In which part of the cone cell do we find mitochondria?
The middle section
35
Why do sperm contain digestive enzymes?
To break down the outer layers of the egg.
36
Why do your cells need to take in substances such as glucose and oxygen?
For respiration
37
How do dissolved substances and gases mov into and out of your cells?
Across the cell membrane
38
What is diffusion?
The spreading out of particles of a gas or any substance in solution from a high concentration to a low concentration.
39
When will the diffusion take place quickly?
When there is a big difference in concentration between two areas.
40
When will the rate of diffusion be slow?
When there is a small difference in concentration between two areas.
41
What is the net movement?
Particles moving in - particles moving out
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What is the difference between two areas of concentration known as?
The concentration gradient
43
What affects the rate of diffusion?
Temperature
44
How does temperature affect diffusion?
Am increase in temperature means the particles in a gas or a solution move more quickly. Diffusion takes place more rapidly as the random movement of the particles speeds up.
45
What important substances can move across you cell membrane by diffusion?
Water , simple sugars like glucose
46
How does oxygen get to our cells?
The oxygen we need for respiration passes from the air into the lungs. From there it gets into the red blood cells through the cell membranes by diffusion.
47
How can individual cells be adapted to make diffusion easier and more rapid?
To increase the surface area of the cell membrane, - more room for diffusion to take place. By folding up the membrane the area over which diffusion can take place is greatly increased. Therefore the rate of diffusion is also greatly increase this means much more of a substance moves in a given time.
48
Fill in the gaps:
| The greater the difference in the concentration, the ________ the rate of diffusion.
Faster
49
What is a multicellular organism?
An organism which is made up many cells which work together. Some of the cells are specialised for different functions in the organism.
50
What do cells do using the development of a multicellular organism?
They differentiate - specialise for their function
51
What is a tissue?
A group of cells with similar structure and function working together.
52
What do muscular tissues do?
They can contract to bring about movement.
53
What do glandular tissues do?
They contain secretory cells that can produce substances such as enzymes and hormones.
54
What tissues do plants have?
Epidermal tissues- cover the surface and protect
Mesophyll tissues- contain chloroplasts and carry out photosynthesis
Xylem and phloem- transport tissues which carry water and dissolved ions from the roots up to the leaves and the dissolved food from the leaves around the plant.
55
What are organs?
A group of different tissues working together to carry out a particular function.
56
Give one example of an organ and what tissues it contains:
The stomach:
Muscular tissue- to churn the food
Glandular tissue- produce digestive juices to break down the food
Epithelial tissue- covers the inside and outside of the organ.
57
What are the two important functions of the pancreas?
It makes hormones to control our blood sugar. It also makes some of the enzymes that digest our food.
58
How have the organs adapted to make the exchange of materials easier and more efficient?
1. Increases surface area over which the materials are exchanged. The bigger the SA the quicker the diffusion
2. Increase the concentration gradient across the membranes.
59
What are the levels of organisation?
Cells, tissues, organs, organ systems, whole body
60
How are the lungs adapted to provide the biggest possible surface area for the exchange of materials within organs.
Many alveoli to give a large SA for exchange of oxygen and carbon dioxide.
61
What are organ systems? And give one example
Groups of organs that all work together to perform a particular function.
Human digestive system
62
What is the digestive system and what does it do?
The digestive system is a system of organs all working together to bring about the digestion of your food.
63
Briefly explain the process of digestion
The food you take in is made up of large insoluble molecules, which your body cannot absorb.
They need to be broken down or digested to form smaller soluble molecules which can then be absorbed and used by your cells.
64
Why does the digestive system contain many different organs such as the pancreas and salivary glands?
These glands make and release digestive juices containing enzymes to break down your food.
65
What are the main organs where food is digested?
Stomach and small intestine.
66
What happens the small intestine and after that?
All the soluble molecules are absorbed into your blood, after they get transported in the bloodstream around your body.
67
What are the main organs in plants?
Stems- supports leaves and flowers
Roots- takes up water and minerals from the soil
Leaves- carries out photosynthesis
68
What do the xylem and phloem do?
Xylem-transports water and minerals
| Phloem- transports dissolved food
69
What is the equation for photosynthesis?
Carbon dioxide+water-->glucose + oxygen
70
What do chloroplasts contain?
Chlorophyll
71
What happens during photosynthesis?
Light energy is absorbed by the chlorophyll in the chloroplasts. This energy is then used to convert carbon dioxide from the air plus water from the soil into a simple sugar called glucose. The chemical reaction also produces oxygen gas as a by product. The gas is released into the air which we can use when we breathe it in.
72
How can you test for starch?
Add iodine solution and when it reacts with starch it should turn dark blue.
73
Some of glucose produced during photosynthesis is used immediately by the cells of the plant what happens to the rest?
A lot of the glucose made is converted into insoluble starch and stored.
74
How can you show that a plant is photosynthesising?
You can collect the bubbles of gas coming of water plants, and the gas will relight a glowing splint showing that it is oxygen.
75
How can you test for starch using a practical?
Take a leaf from from a plant kept in the light and from the dark for at least 24 hours. The waterproof cuticle will not allow the iodine to reach the cells and the chlorophyll will mask any colour changes so you need to treat the leaves by boiling them in ethanol first to destroy the cuticle and remove the colour. Rinse and use iodine solution.
76
What is chlorophyll?
The green substance that absorbs light energy in plants.
77
How are the leaves of plants perfectly adapted?
1. They contain chlorophyll in the chloroplasts to absorb the light energy.
2. Most leaves are broad giving them a big surface for the light to fall on.
3. They have air spaces that allow carbon dioxide to get to the cells and oxygen to leave them by diffusion.
4. They have veins which bring plenty of water to the cells.
78
What's the function of stomata?
To allow gases to move in and out of the leaf.
79
In which part of the cell is energy released during respiration?
Mitochondria
80
Why is it possible to see a bacterial colony but not a single bacterium?
One bacterium is very tiny. Many bacteria massed together in a colony can be seen.
81
Named a single celled organism.
Yeast cell
82
How are plant cells specialised?
Mesophyll cells contain many chloroplasts that photosynthesise
83
What determines the net movement of particles across a cell membrane?
The concentration on either side of the membrane.
84
What do glandular tissues produce?
Enzymes or hormones
85
Where is soluble food absorbed?
In the small intestine
86
Name three organs in the human digestive system
Pancreas
Stomach
Liver
Small intestine
87
Describe in detail what happens to food as it passes through the digestive system.
The insoluble food is mixed with digestive juices produced by glands. It is digested in the stomach and small intestine. Bile produced by the liver is added to the food. Absorption of the soluble food is absorbed by the small intestine and the large intestine absorbs water.
