The Plant Body and Its Functions

Question 1

when did plants first appear on earth?

Answer 1

500-460 million years ago

Question 2

What happened to plants 460million years ago?

Answer 2

They were very small and moss-like. They had no roots and therefore lived attached to soil and rock bordering water sources

Question 3

When and how was soil first created?

Answer 3

Around 400 million years ago. Plants developed roots and those roots dug into the rock causing it to break into small pieces. Plants also released carbon dioxide from their roots and when they died allowed the rock to further break down and gain nutrients to form soil.

Question 4

When did plants develop roots and what did this allow?

Answer 4

Around 425 million years ago. Roots allowed plants to grow transport systems to carry water through their bodies. This also enabled them to be able to move away from water sources. Plants also started to become taller and compete for sunlight.

Question 5

When did plants start to photosynthesis and how did this impact the Earth’s environment forever?

Answer 5

Around 360 million years ago. Plants used CO2 from the atmosphere to react with the suns energy to create sugars which are their food source. Oxygen would then be released back into the environment.
more CO2 consumed by plants = less CO2 in the atmosphere = cooler atmospheric temperatures.

Question 6

What 2 systems is a plant composed of?

Answer 6

Shoot system(above ground) and Root system(underground)

Question 7

What does the shoot system consist of and what are its functions?

Answer 7

Consists of:
-leaves
-stems
-flowers
Functions:
-Photosynthesis ( create nutrition/ energy)
-Reproduction (happens in the flower)
-Storage (water and nutrients)
-Transport (water and nutrients)
-Hormones (allow or inhibits for growth of plant)

Question 8

What does the root system consist of and what are its functions?

Answer 8

Consists of:
-roots
-modified stems
Functions:
-Anchorage (keep the plant in the soil)
-Absorption (of water and nutrients)
-Storage (of water and nutrients)
-Transport (of water and nutrients)
- Hormones (regulate growth)

Question 9

How are plants classified?

Answer 9

2 categories:
-Vascular plants
-non-vascular plants

Question 10

What where the ancestors of modern day plants?

Answer 10

Green algae lived 500 million years ago
- plant-like protists
-singled celled
-aquatic
-able to photosynthesize
- had cell walls
- developed a mutation that allowed them to attach to rock

Question 11

What happened to early plants?

Answer 11

Their metabolism allowed them to convert rock into the soil using CO2 emissions through their roots, which was a chemical mutation.

Question 12

When did multicellularity in plants occur? When did the Plant Kingdom start?

Answer 12

Around 400 million years ago
The plants were considered “true plants”

Question 13

When did plants develop vascular tissue? And what did this allow for?

Answer 13

Around 400 million years ago. Xylem and phloem were developed which allowed the plant to absorb and transport water, through the xylem, and sugars, through the phloem. Plants got bigger and could move away from water sources.

Question 14

What are vascular tissued plants called?

Answer 14

Tracheophytes

Question 15

When were seeds produced by vascular plants? What other plant organs developed at the same time? Explain the effect.

Answer 15

Around 230 million years ago. Vascular plants started producing seeds. This meant that seed dispersal improved. Organs such as leaves, stems and roots allowed the plant to thrive.

Question 16

What are seed-producing vascular plants called?

Answer 16

Spermatophytes

Question 17

What are flowering plants called? Explain their benefits.

Answer 17

Angiosperms
-encased its seeds in fruit
-found everywhere in the world

Question 18

What are the 2 classifications of flowering plants?

Answer 18

Monocot plants and Eudicot(dicot) plants

Question 19

What are conifers called?

Answer 19

Gymnosperms

Question 20

Where do conifers/ gymnosperms store their seeds? What are the characteristics of gymnosperms?

Answer 20

-Seeds stored in cones
-needle-shaped leaves
-water not required to disperse seeds

Question 21

Ferns are called?

Answer 21

Pteridophytes

Question 22

Characteristics of pteridophytes?

Answer 22

-Spore-producing vascular plants
-live in shady moist environments
-don’t need abundant light
-use water for spore dispersal

Question 23

What are mosses called?

Answer 23

Bryophytes

Question 24

Characteristics of bryophytes?

Answer 24

• not a vascular plant
• lack of transport system
• remain small and low to the ground
  -moist environments
  -water needed to distribute spores
  -sexual reproduction = no seeds

Question 25

Name the different types of plant tissues and their uses.

Answer 25

-Meristematic Tissue (where new cells are produced)
-Dermal Tissue (forms the outer covering of the plant)
- Ground Tissue (makes up most of the inside of the plant and has many functions)
- Vascular Tissue (transports water and nutrients and minerals through the plant and provides support)

Question 26

Name the 3 different types of Ground tissue cells and their functions.

Answer 26

1) Parenchyma Cells
- make up most of the plant
-photosynthesis
-storage
-gas exchange
-protection
-have many chloroplasts
-tissue repair and replacement
-are spherical in shape and flatten when tightly packed together
- have large central vacuoles
2) Collenchyma Cells
-are elongated strips and strings of cells
-occur in cylinders and offer support to surrounding cells
-are flexible and allow the plant to bend and sway without snapping
3) Sclerenchyma Cells
-have very thick secondary walls that contain lignin
-die once maturity is reached and only cell walls remain to keep the plant upright
-cells have an irregular shape (needle-shaped and small interior spaces)
-support mature plant
responsible for the gritty texture of fruits and seeds

Question 27

Where are the ground tissues located?

Answer 27

1) Parenchyma Cells
- located in leaves, stem, roots and fruits
2) Collenchyma cells
-found in stems and leaves
3) Sclerenchyma Cells
-randomly throughout the plant
-covering the seed
-form elastic tissues

Question 28

What are meristems? What are the 3 types of meristematic tissues? Where are they located? What are their functions?

Answer 28

Meristems are embryonic tissues of a plant where rapid cell division occurs to produce specialized cells.
1) APICAL meristems:
-located at the shoot and root tips
-allow for roots and shoot to grow longer
2) INTERCALARY meristems:
-found along the stems and at the base of leaf blades
cause roots and stems and leaves to grow longer
-allow the plant to continue to grow after being cut
3) LATERAL meristems:
-increase the circumference of the plant (width)
-called secondary growth
-strengthens stem and supports plant as it grows taller
3a) vascular cambium:
- meristematic tissue that runs along the length of roots and stems
-produces new vascular tissues
-necessary for secondary growth
3b) cork cambium
-produces cells that have tough cell walls
-forms a protective layer around the outside of stems and roots
-makes up the outer bark of woody plants

Question 29

What is the epidermal tissue and its purpose?

Answer 29

Is a single layer of dermal tissue that forms a protective covering over the body of non-woody plants and young woody plants.

Question 30

What is the equivalent of the epidermis in mature woody plants?

Answer 30

Periderm. It eventually forms the cork tissue which becomes the bark around woody plant stems and roots.

Question 31

Explain the point of guard cells and stomata…

Answer 31

Guard cells: a pair of cells surrounding a pore-like opening called a stoma. It regulated the opening and closing of the stoma
Stomata: the pore opening where carbon dioxide diffuses in and oxygen out during the day. During the night stomata are closed due to no sunlight and therefore no need for CO2 intake for photosynthesis, water vapour also diffuses from the leaf
* located in the leaf of the plant

Question 32

What are trichomes?

Answer 32

-Tiny growths on the surface of the epidermis. -Found on stems and leaves
-Keep the plant cool
-may contain toxic substances to keep predators away

Question 33

What are root hairs?

Answer 33

-tiny extensions of single epidermal cells
-increase surface area for absorption of water and nutrients in the roots

Question 34

What is the purpose of ground tissues? What are examples?

Answer 34

-Storage, photosynthesis and plant support. —Takes up the most space inside of a plant
- made up of parenchyma, collenchyma and sclerenchyma cells

Question 35

what are the 2 different types of vascular tissue?

Answer 35

xylem and phloem

Question 36

What is the purpose of the xylem and where is it located?

Answer 36

Xylem is located in the stem and found in vascular bundles along with the phloem in non-woody plants.
-xylem transports water and minerals from the roots to the leaves

Question 37

What is the purpose of phloem and where is it located?

Answer 37

Phloem in located in the stem and leaves and roots and carries nutrients and sugars from the leaves to the roots and anywhere it is needed for metabolism.

Question 38

What is the xylem made of?

Answer 38

In gymnosperms, it’s made of tracheid cells.
In angiosperms, it’s made of both tracheid and vessel element cells. Contains small holes called pores in the xylem cells to allow for the movement of water between the xylem and phloem.

Question 39

What is the phloem made of?

Answer 39

Phloem is made of 2 cell types: companion cells and sieve tube elements. Sieve tube elements allow for sugars to pass through them since they are dead inside. Companion cells are attached to the phloem tubes and support and help each sieve tube element survive by providing it with its basic needs.

Question 40

What is the function of a plant’s stem?

Answer 40

-support leaves and flowers
-transport water and nutrients and sugars to parts of the plant and the leaves
-storage of sugars

Question 41

What are the 2 different stem categories and their characteristics?

Answer 41

1)Herbaceous Stems:
-grow annually and do not live in winter
-usually have green stems
-some photosynthesis can occur trough thin epidermis layer
-usually don’t survive more than a year and don’t get taller than 1m
2)Woody Stems:
-perennial (survive the winter)
-covered by bark
-increase in diameter every year
-vascular cambium produced new xylem and phloem every year

Question 42

What are vascular bundles?

Answer 42

They are arrangments of phloem and xylem tissue together.

Question 43

How do the vascular bundles look in herbaceous stems or roots?

Answer 43

Monocot:
-vascular bundles are scattered in stems
- create a ring around the centre of the core of the root
Dicot:
-Vascular bundles create a ring structure around in inner edges of the stem
-xylem creates a star or X shape in the middle of the plant root

Question 44

How do vascular bundles look in woody stems or roots?

Answer 44

Woody plants are sometimes dicots but rarely monocots.
-when they reach maturity the vascular bundles of attach together to form continuous rings around the interior of the stem from the centre
-vascular cambium makes a new ring appear yearly

Question 45

What are the different types of specialized stems and what are their functions/characteristics?

Answer 45

1) Fleshy STems:
-extra water storage (ex: cacti)
2) Tubers:
-enlarged part of an underground stem
-provide energy and nutrients for growth
-ex: potatoes
3)Bulbs:
-shortened compressed stems surrounded by fleshy leaves
-stores energy for the next season of growth
- ex: tulips, onions
4) Corms:
-composed entirely of stem tissue with some scaly leaves at its top
-stores starch to fuel growth and help the plant survive in unfavourable conditions
5) Stolons:
- horizontal stems that grow above ground along the soil’s surface
-aids in asexual reproduction
6) Rhizomes:
-horizontal stems that grow underground
-store starches and proteins and allow the plant to survive underground

Question 46

What is the purpose of roots?

Answer 46

-absorb water and minerals
-anchor the plant into he soil and prevent it from being blown away
-store sugars and carbohydrates
-produces hormones

Question 47

What are the types of roots a plant can have?

Answer 47

1) Taproot
2) Fibrous root
3) Adventitious root

Question 48

What is a primary root?

Answer 48

The first root that grows from the seed.

Question 49

What are the 2 types of primary roots and their characteristics?

Answer 49

1) Taproot
- one thick root with smaller lateral branching roots
- ex: carrots
- able to tap into water sources that are farther down in the soil
- anchors plant
-food and water storage
-absorbs water and minerals
2) Fibrous roots:
- made up of many smaller branching fibre-like roots
- not all the same size and grow from a central point
- do not grow as deep as taproots
-anchors plant
-absorbs water and minerals

Question 50

What are secondary roots?

Answer 50

• lateral roots that grow out from the primary root
• smaller in diameter than primary root

Question 51

What are adventitious roots?

Answer 51

• replaces the main root
• grows out of something other than the primary root (stems)

Question 52

Describe the parts of a root and their functions.

Answer 52

Root Tip:
- the apical meristem where cells are produced to elongate the root
Root Cap:
- loose mass of cells
- consists of parenchyma cells
- protects the growing root tip
Xylem:
- conducts water upwards
Phloem:
- conducts carbohydrates downward to the roots
Root Hairs:
- branches of secondary roots
- increases surface area for the better absorption of water and minerals

Question 53

What are the specialized root structures and their functions?

Answer 53

1) Aerial Root
- absorbs water from the air
- doesn’t need soil
- found in plants that need to grow on top of other plants and densely populated moist forests
- often climb other plants
2) Storage Root:
- storage for carbohydrates
- ex: radishes
3) Prop and Buttress:
- found where the soil is less compact
- support weak and shallow roots
- emerge from primary roots and may go into the ground or stay above ground
- ex: mangroves
4) Parasitic Roots:
- use roots to absorb and feed on nutrients from host plants
5) Contractile Roots:
- shrink in size
- causes the stem to sink into the earth
- eventually, die
- ex: agave

Question 54

What is the function of the leaves?

Answer 54

• primary site of photosynthesis
• used to maximize exposure to sunlight
• provides food for the rest of the plant

Question 55

What is the photosynthesis word equation?

Answer 55

carbon dioxide + water = carbohydrates + oxygen

Question 56

What is the difference between the leaf type of monocots and dicots?

Answer 56

Monocots:
- one leaf blade attached to one petiole
- called a simple leaf
Dicots:
- compound leaf
- multiple lead blades attached to the petiole

Question 57

Name and explain the anatomy of a leaf from its top layer of cells to its last layer of cells.

Answer 57

Cuticle:
- a waxy substance that prevents water loss in the leaf
- made of cutin
Upper Epidermis:
- a single layer of cells
- secretes cuticle = protection
Palisade Mesophyll:
- cells are very close together
- cylinder-shaped and densely packed
- contains a big amount of chloroplasts in its cells
Spongy Mesophyll:
- irregular shape and loosely packed
- allows air to circulate = space for the diffusion of water and gases
Vein:
- made up of vascular bundles of the xylem and phloem
Guard Cells:
- kidney bean shaped
- found in pairs
- regulate the opening and closing of stomata
Stomata:
- pores
- allows for the diffusion of gases
- during the day guard cells swell and the stomata open; ions move into the guard cells; water follows by osmosis
- during the night the guard cells shrink and the stomata close; ions move out of the guard cells; water moves out

Question 58

What are the abiotic factors of leaf structure?

Answer 58

Low light/shade:
- trap low amounts of light
- found mainly in rainforests
- can catch large amounts of sun, therefore if exposed directly to the sun a lot of water will be lost
- in shaded environments is best suited
Low water/ precipitation:
a) Needles:
- small surface area = thick layers of water storage tissue = less water loss
- the downside is not as much photosynthesis occurs
b) Thicker tissue layers:
- thick layers of water storage tissues
- can hold more water
c) Think Cuticle
- more protection from the sun = less water loss
- also less sun gets into the plant = less photosynthesis
d) Spines
e) Fewer Stomata

Question 59

What are the biotic factors of leaf structure?

Answer 59

Herbivores:
- like to feed on mild-flavoured leaves
a) Toxic Chemicals:
- will prevent animals from feeding
- ex: caffeine and nicotene
b) Taste
- animals may not eat the leaves if they don’t like the taste
c) Texture:
- some gritty and prickly textures may avert animals and predators of the leaves
Pollinators:
- plants attract insects and birds to transfer pollen
- petals are modified leaves
- petals use resources to attract pollinators
- petals allow for gametes to be produced through pollination

Question 60

Where is the pollen made on a flower?

Answer 60

Anther

Question 61

Where is the anther?

Answer 61

On the filament stalk

Question 62

What is the anther and the filament together called and what does it represent?

Answer 62

The stamen. This is the male reproductive organ of the plant/ flower.

Question 63

What is the female reproductive organ in a flower/ plant?

Answer 63

The pistil

Question 64

Where does the pollen enter to start fertilizing the female egg cell?

Answer 64

The pollen sticks to the stigma and then falls down the style to get to the ovary where the female egg cells are found. The female ovules then join with the sperm in the pollen and create a gamete.

Question 65

What is the leaf-like enclosure of the flower?

Answer 65

The sepals.

Question 66

What is the fruit of the plant?

Answer 66

The fruit of the plant is the female reproductive organ and contains the seeds.

Question 67

What is a perfect vs imperfect flower?

Answer 67

A perfect flower contains both male and female parts. And an imperfect flower only contains the parts of one sex and therefore needs to be fertilized by another organism of the same species.

Question 68

What is pollination?

Answer 68

A process that occurs when the pollen (male gametophyte) lands on the female reproductive structure of a plant of the same species.

Question 69

What is self-pollination?

Answer 69

When a flower can pollinate itself or another flower on the same plant stock.
Downside: can lead to loss of genetic variation and inbreeding.

Question 70

What is cross-pollination?

Answer 70

When an angiosperm of a plant receives pollen from another plant organism = more genetic diversity.

Question 71

What is a monoecious plant?

Answer 71

A plant with both male and female reproductive structures but on different flowers of the same plant.

Question 72

What is a dioecious plant?

Answer 72

A plant that carries either female or male reproductive structures but not both. The female and male reproductive structures appear on different organisms of the same species.

Question 73

What is asexual reproduction and when does it happen?

Answer 73

A plant reproduces offspring that is genetically identical to it and each other = clones
Plants survive well under favourable conditions.

Question 74

What are the two methods of asexual reproduction in plants?

Answer 74

1) Apomixis
- where a seed forms in a plant without the union of gametes
2) Vegetative Propagation:
- where a new plant grows from the existing structure of another plant (ex: stems, bulbs, corms, rhizomes)

Question 75

How does sexual reproduction in plants occur?

Answer 75

Alters between gametophyte and sporophyte.
Involves both haploid and diploid stages.
1) Spore with haploid chromosomes goes through mitosis in the earth
2) This produces a gametophyte plant which is multicellular and has groups of identical cells
3) Gametophyte forms a gamete through specialized cells
4) The gamete is then fertilized by another gamete of the opposite sex to form a zygote
5) The zygote creates a seed that grows to form a Sporophyte
6) Sporophyte has a diploid number of chromosomes
7) Sporophyte goes through meiosis to form spores which start the whole process again

Question 76

What are the differences in vascular bundles between monocots and dicots in stems and leaves

Answer 76

Monocots:
- bundles are scattered throughout ground tissue in stems
- arranged in a ring in roots
Dicots:
- arranged in distinct rings on stems
- have a star or x shaped form in roots

Question 77

What are the differences between the seed leaves and mature leaves of monocots and dicots?

Answer 77

Monocots:
- one leaf will sprout when the seed starts growing
- the mature leaf will have veins parallel to each other
Dicot:
- two leaves will sprout when the seed starts growing
- mature leaves are either pinate or palmate
a) palmate: the veins look like they do on the palm of your hand; unordered
b) pinnate: the veins in these leaves will be ordered but not parallel to each other

Question 78

What is the difference between flowers in monocots and dicots?

Answer 78

Monocots:
- flowers have petals in 3s and multiples of 3
Dicots:
- have flowers petals in 4s and 5s and multiples of 4s and 5s

Question 79

What is the difference between the root structure of monocots and dicots?

Answer 79

Monocots:
- typically fibrous
Dicots:
- typically taproots

Question 80

What is the difference in the seed structure of monocots and dicots?

Answer 80

Monocots:
- endosperm is very large
- cotyledon is very small
Dicots:
- very small endosperm almost not able to be seen
- whole seed is taken up by the cotyledon

Question 81

What is the cotyledon?

Answer 81

Tissue that becomes the embryonic first leaves of the seedling.

Question 82

What is endosperm?

Answer 82

Tissue that surrounds and nourishes the embryo in the seeds of angiosperms.

Question 83

What is active transport?

Answer 83

When roots take up water and minerals from the soil. This requires that water perform osmosis and that other minerals are absorbed by extra exerted energy. Cellular respiration occurs.

Question 84

When is water absorbed into the root by osmosis?

Answer 84

When the roots absorb minerals the concentration of the minerals becomes greater than the concentration of minerals in the soil outside the roots. Water then needs to be absorbed through osmosis to dilute the minerals.

Question 85

How does osmosis work?

Answer 85

Water moves from the side of greater water concentration to the side of lower water concentration. This assures that both sides of the cell membrane (inside and outside the cell) are diluted and saturated enough for the cell to absorb both the water and the minerals.

Question 86

What is root pressure?

Answer 86

Root pressure is a process that happens after the water and minerals are absorbed. The water being pulled in by osmosis creates a high pressure in the roots which pulls up the water partially in the roots to where there is less pressure. Root pressure can take water up to about ten metres.

Question 87

What is adhesion and where does it happen?

Answer 87

Adhesion occurs in the stem. It is when water chemically sticks to the cell walls of the vessel elements of the xylem. This creates a pulling force upwards.
= PULLING FORCE

Question 88

What is cohesion and where does it happen?

Answer 88

Cohesion occurs in the stem and works at the same time as adhesion in the xylem. Cohesion is the ability of water to stick to itself. Hydrogen bonding in the water molecules causes narrow columns of water molecules to stick together and move up the xylem through adhesion.

Question 89

What is transpiration and what causes it?

Answer 89

Transpiration is the water loss in the leaves at the top of a large plant.

Question 90

How does the water arrive at the leaves before transpiration?

Answer 90

Water pressure is higher at the roots than at the leaves. This causes the water to be pulled upwards in TRANSPIRATIONAL PULL from the stem to the leaves. Water moves from areas of higher pressure to areas of lower pressure.

Question 91

What affects the rate of transpiration?

Answer 91

Higher temperature = higher rate of transpiration

Question 92

what is translocation?

Answer 92

The movement of needed products of photosynthesis throughout the plant body.

Question 93

What isn’t known about translocation?

Answer 93

-phloem is living
- phloem transports sugars upwards and downwards, therefore: bidirectional movement is unexplained
- rates of flow of the sugars are unexplained because we don’t know what causes faster or slower rates of flow in phloem.

Question 94

How do carbohydrates move?

Answer 94

They move from the area where they are created (the leaves) to areas where they are stored/ needed.

Question 95

What is phloem loading?

Answer 95

When the sugars created in the spongy mesophyll of the leaves are actively transported into the phloem sieve tube cells.

Question 96

What does hypotonic mean?

Answer 96

More solvent less solute = less dissolved solute = less concentrated solution