Photosynthesis and Plant Reproduction Flashcards
(94 cards)
1
Q
What is sexual reproduction?
A
- Requires 2 parents
- Offspring is genetically different to parents
2
Q
What are the advantages to sexual reproduction?
A
- Variation in population
- Species can adapt to new environments
- Less likely to be affected by disease
3
Q
What are the disadvantages of sexual reproduction?
A
- Takes a lot of time and energy to find a mate
- Impossible for isolated individuals
4
Q
What is asexual reproduction?
A
- One parent is needed
- Offspring is identical to parent (and clones)
5
Q
What are the advantages of asexual reproduction?
A
- Population can increase rapidly
- Can exploit a suitable habitat quickly
6
Q
What are the disadvantages of asexual reproduction?
A
- No variation in population
- Species only suited to 1 habitat
- Disease may affect all individuals in a population
7
Q
Function the the petals:
A
Brightly coloured to attract insects
8
Q
Function of the anther:
A
Produces male gametes (pollen grains)
9
Q
Function of the stigma:
A
Top of the female part of the flower which collects pollen grains (sticky)
10
Q
Function of the ovary:
A
Produces the female gamete (contains ovule) - becomes fruit after fertilisation
11
Q
Function of the nectary:
A
Produces a sugary solution called nectar, which attracts insects
12
Q
Function of sepals:
A
Protects the unopened flower
13
Q
Function of the stamen:
A
Male part of the flower - consists of an anther held up on the filament
14
Q
Function of the ovule:
A
A structure that becomes a seed when fertilised
15
Q
What is the male part of the flower?
A
It is called the stamen and consists of the anther and filament
16
Q
What is the female part of the flower?
A
It is called the carpel and consist of the stigma, style and ovary
17
Q
Where is the male gamete made?
A
In the ovule
18
Q
Where is the male gamete found?
A
Inside the pollen grain
19
Q
Where is the female gamete found?
A
In the anther
20
Q
What is the female gamete called?
A
An ovule
21
Q
What are two types of asexual reproduction in plants?
A
- Cuttings
- Grafting
22
Q
What are cuttings?
A
- Part of a plant stem, leaf, or root cut off and used for producing a new plant
- An artificial propagation method
23
Q
What is grafting?
A
A shoot or bud of one plant is is inserted into or joined to the stem, branch, or root of another plant so that the two grow together as a single plant
24
Q
What is the definition of pollination?
A
The transfer of pollen grains from the anther to the stigma
25
Characteristics of insect pollinated flowers?
- Brightly coloured, big petals to attract insects
- Nectar present to attract insects
- Pleasant scent to attract insects
- Stigma is sticky to collect pollen and inside the flower
- Anther is positioned to rub pollen onto insects and surrounds the stigma
- Pollen grains have hooks for hooking into insect fur
26
Characteristics of wind pollinated flowers:
- Petals are small and green (no need to attract insects)
- Nectar not present
- Scent not present
- Stigma is feathery to catch pollen blown by wind outside the flower
- Anthers are exposed to the wind so pollen can be easily blown away, long filament outside the flower
- Pollen grains are small, smooth, light and large in numbers
27
What is self pollination?
Pollen falls from the anther onto the stigma of the same flower - not preferred as it reduces variation
28
What is cross pollination?
Pollen from anther lands in stigma of a different plant (same species, different flower)
29
Ways for plants to prevent cross pollination for happening:
- Stigma above the anther/stamen - pollen cannot fall on stigma
- Maturation of anther/stigma at different times - pollen cannot fall on stigma
30
What is the process of fertilisation?
- The pollen grain lands on the stigma of the plant species, stimulating the pollen tube to grow
- The pollen grain travels down the style to the ovary
- The pollen grain travels down the tube connected to the micropyle
- The male and female gamete fuse totgehe in the ovule to create a zygote
- The zygote undergoes cell division and develops into an embryo
31
How does fertilisation in plants begin?
The pollen grain lands on the stigma of the plant species, stimulating the pollen tube to grow
32
Male gametes in plants:
- Pollen doesn’t have a tail
| - Pollen protects the nucleus before releasing it
33
Male gametes in animals:
- Sperm has a tail
| - Sperm doesn’t release the nucleus
34
What is the process of fertilisation?
The fusion of a male and female gamete to produce a zygote that undergoes cell division and develops into an embryo
35
How can a seed become dormant?
Through lack of warmth and moisture
36
Why are seeds dispersed away from the parent plant?
To reduce competition
37
What are the 4 mechanisms of seed dispersal?
- Wind
- Water
- Mechanical
- Animal
38
Function of the cotyledon:
- The food store
- Starch
- Insoluble
39
Function of the plumule:
- Embryo shoot
| - Doesn’t affect osmosis
40
Function of the radicle:
- The embryo root
41
Function of the testa:
- The tough seed coat
42
Function of the micropyle:
- Hope made by the pollen tubes
43
Why is it important for water to enter the seed to activate germination?
To activate the Enzymes by breaking down the food store to be used in germination
44
What is dry mass?
It is the mass of solid matter with all water removed
45
What happens when the food store in the cotyledon is broken down at the beginning of germination?
- Amylase (the enzymes) break down the starch into maltose
- The maltase breaks down the maltose into glucose
- The glucose is used in respiration to release energy in the form of ATP
46
What happens to the dry mass during germination?
It decreases
47
Why does the dry mass decrease during germination?
The seed loses weight as it uses up the stack stores in the cotyledons as the seedling can’t photosynthesise yet as it’s still underground
48
What happens after the seed breaks free from being underground?
The seedling’s weight increases as it begins to grow leaves, meaning that it can photosynthesise, meaning that the plant can grow even more
49
Describe an investigation into the effect of different concentrations of Ethanol on the germination speed of a seed (6)
- Change - the concentration of Ethanol
- Organism - Apple seed
- Range - 20%, 40%, 60%, 80%, 100% concentration of ethanol in the solution
- Repeat - each concentration x3
- Measurements - a cm ruler
- Measure - the height of the plant after 6 weeks
- Same - the pH of the soil
- Same - Temperature (degrees Celsius)
50
Describe the method for a practical, investigating the conditions needed for seed germination
- Cotten wool is places at the bottom of four boiling tubes, each containing five cress seeds
- Each test tube is then individually set up:
* Test Tube A: moist cotton wool and places in warm environment (hot water bath set at appropriate temperature)
* Test Tube B: dry cotton wool and placed in warm environment (hot water bath set at appropriate temperature)
* Test Tube C: moist cotton wool and is placed in a cold environment (bucket of ice)
* Test Tube D: cotton wool soaked in boiled water that is cooled off, and layered with oil on top
- After all test tubes are set up, cress seeds in each respective test tube are allowed to adjectives to new environment for a fixed number of days
- After a fixed number of days has passed, results are compared via:
* Number of cress seeds germinated
* Height of germinated seed
51
What would the test tube results be for the practical, investigating the conditions needed for seed germination?
- Test Tube A - All factors present
- Test Tube B - only water present
- Test Tube C - only optimum temperature present
- Test Tube C - only Oxygen present
Test Tube A
52
Why is water needed in seed germination?
To activate enzymes to break down the food store in the cotyledon, from starch into glucose (energy in the form of ATP)
53
Why is oxygen needed in seed germination?
For aerobic respiration to produce energy in the form of ATP for growth
54
Why is the optimum temperature (warmth) needed in seed germination?
For optimum enzyme activity be to facilitate survival and geothermal of the seed (too cold and the enzymes won’t work as efficiently, too hot and the enzymes will denature and stop working completely)
55
What is the word equation for photosynthesis?
Carbon dioxide + water —-> glucose + oxygen
56
What is the chemical equation for photosynthesis?
6CO + 6H20 —> C6H12O6
57
Where does photosynthesis occur?
In the chloroplast
58
How does water reach the chloroplast?
Through the roots
59
How does carbon dioxide reach the chloroplast?
Through the stomata
60
What is photosynthesis?
It is the conversion of light energy into chemical energy
61
Factors affecting the rate of photosynthesis?
- Light intensity
- CO2 concentration
- Temperature
62
How does light intensity affect the rate of photosynthesis?
More light = higher rate of photosynthesis
63
How does CO2 intensity affect the rate of photosynthesis?
More CO2 = higher rate of photosynthesis (more reactant available)
64
How does Temperature affect the rate of photosynthesis?
Higher temperature = higher rate of photosynthesis - higher kinetic energy - more collisions between active site of enzyme and substrate (up until a point - enzymes will denature and too much water loss if too hot!)
65
What is a limiting factor?
A factor present in an environment that controls a process
| * see notes for graph of limiting factors and explanations
66
What are the layers of a leaf in order from top to bottom?
- Upper epidermis
- Palisade Layer (mesophyll layer)
- Spongy Layer (Mesophyll layer)
- Lower epidermis
67
What is contained in the upper epidermis?
The waxy cuticle layer
68
What is the purpose of the waxy cuticle layer?
It is the waterproof layer which stops water loss
69
What is contained in the palisade layer?
Palisade Cells at the top of the leaf, close to the light, tightly packed totgehe and full of chloroplasts
70
What is contained in the spongy mesophyll layer?
Many airspaces are in the spongy mesophyll tissue
71
Why are many airspaces found in the spongy mesophyll tissue?
To allow for more efficient gas exchange
72
Why are cells not tightly packed in the spongy mesophyll layer?
So they can have a lathe surface area available for gas exchange and some chloroplasts
73
What is located in the lower epidermis?
- Guard cells
| - Stomata
74
What is the function of guard cells
To open and close the stomata to control water loss
75
What is the function of stomata?
To allow gas to move in and out of the leaf
76
What do plants require mineral ions for?
Growth
77
What do plants require magnesium ions for?
Chlorophyll
78
What do plants require are nitrate ions for?
Amino acids
79
What can you find in plant cells?
- Nucleus
- Cells wall (made of cellulose)
- Cytoplasm
- Vacuole
- Cell membrane
- Ribosomes
- Mitochondria
- Chloroplasts
80
Why do root hair cells not require chloroplasts?
Because they do not carry out the process of photosynthesis as they are underground and have no sunlight
81
Practical: investigate photosynthesis, showing the evolution of oxygen from a water plant, the production of starch and the requirements of light, carbon dioxide and chlorophyll - answer with CORRMMSS
Change - light intensity (using LED bulb, doesn’t affect temperature)
Organism - pondweed, Cabomba (in boiling tube containing 45 cm3 of sodium hydrogencarbonate solution)
Range - 10, 8, 6, 4, 2 cm away from the pondweed
Repeat - x3
Measure - the volume of oxygen produced per minute
Measurements - cm3
Same - the concentration of CO2
Same - temperature
82
Starch Testing method:
Iodine solution is used to test leaves for the presence of starch. You need to:
1) Heat a plant leaf in boiling water for 30 seconds (this kills the leaf, stopping any chemical reactions from occurring)
2) Add the leaf to boiling ethanol in a water bath for a few minutes (the boiling ethanol dissolves the chlorophyll and removes the green colour from the leaf - it turns white so it is easy to see the change in colour)
3) Wash with water to rehydrate and soften the leaf and spread into a white tile
4) Add iodine solution from a dropping Pipette
83
Starch testing method - what happens after you add iodine solution from a dropping Pipette?
After a few minutes, the parts of the leaf that contain starch turn the iodine from brown to blue/black
84
Starch Testing method - why do parts of the leaf that contain starch turn the iodine from brown to blue/black?
Variegated leaves have green parts (where the cells contain chlorophyll) and white parts (where there is no chlorophyll). Only the parts that were green become blue/black with iodine solution, showing the importance of chlorophyll in photosynthesis. The parts without chlorophyll do not photosynthesise, and so they do not make starch and the iodine does not change colour
85
During photosynthesis a plant absorbs light energy using the pigment chlorophyll. This allows it to convert carbon dioxide and water into glucose. This glucose is:
- Transported to the growing parts of the plant for use in respiration
- Transformed into cellulose, proteins and oils
- Turned into starch for storage
Therefore, to test if a plant has been photosynthesising, you can test the leaf to see if starch is present
86
How is the leaf adapted for gas exchange by diffusion?
- Stomata/guard cells - allows gas exchange of CO2 and O2
- Leaf shape is thick which decreases diffusion distance
- Spongy mesophyll cells have a large surface area and moist surfaces for fast diffusion
- Air spaces between spongy mesophyll cells increase the surface area for diffusion
- On the underside of leaves are small holes, or pores, called stomata. A single hole is called a stomata. Each stomata is surrounded by two guard cells
- When guard cells gain water by osmosis, they curve outwards. They opens the stomata, allowing gases in and out
- Losing water by osmosis causes the guard cells to come closer together, closing the stomata. This stops the
movement of gases, but also prevents water loss
87
What is the definition of diffusion?
Diffusion is the movement of a substance from an area of high concentration to an area of low concentration, and is a random and passive process
88
What is gas exchange like during the day?
- There is more photosynthesis than respiration (as there is sunlight) so oxygen is produced
Net:
- CO2 in
- O2 out
89
What is gas exchange like during the night?
Most of the stomata closes up during the night as no photosynthesis can occur (no sunlight) and also to prevent water loss
90
What is excretion?
Excretion is the removal of the following substances:
- Toxic materials
- Waste products of metabolism
- Excess substances from organisms
91
What is metabolism?
Metabolism is all the chemical reactions in the cells of an organism, including respiration
92
Where is excess car in dioxide and oxygen excreted from the plant?
Through the stomata in the leaves
93
What is carbon dioxide a waste product of?
Aerobic respiration
94
What is oxygen a waste product of?
Photosynthesis
