Practical Lab and Tutorial Lab 2

Question 1

Terrestrial plants descend from ____________

Answer 1

Chlorophytes

Question 2

What is the Alternation of Generations Concept?

Answer 2

Plants spend part of their life as multicellular haploid gametophytes and part as multicellular diploid sporophytes

Question 3

What are the two types of Gametangia in plants? Describe.

Answer 3

Archegonia (egg producer) and antheridia (sperm producer)

Question 4

In mosses, asexual reproduction occurs through _____________

Answer 4

Fragmentation

Question 5

In mosses, the dominant generation is _______________

Answer 5

Gametophyte

Question 6

What is the protonema in moss?

Answer 6

The filamentous pre-gametophyte stage

Question 7

Describe the antheridium and archegonium of mosses

Answer 7

Antheridium has a cup-like shape at the end of a stalk

Archegonium has one long stalk

Question 8

Describe the sporophyte of a moss

Answer 8

Sporophyte is attached to the gametophyte at the foot, consists of a long stalk (seta), and a sporangium at the top.

Question 9

What is the operculum?

Answer 9

The cap on the sporangium of mosses, with the spores inside the capsule.

Question 10

How do ferns reproduce asexually?

Answer 10

Branching/spreading of **rhizomes **

Question 11

In ferns, the dominant generation is ___________

Answer 11

Sporophyte

Question 12

Describe the prothallus. What does it contain? Which reproductive generation is it a part of?

Answer 12

The prothallus is a heart shaped structure in ferns containing the archegonium in the middle, andtheridium near the edge, and rhizoids at the bottom

It is part of the gametophyte generation

Question 13

Describe the reproductive process that occurs from prothallus to frond

Answer 13

Once the sperm from the antheridium has entered the egg in the archegonium, young sporophytes develop from the prothallus with the embryo in the rhizoid region of the plant. A leaf sprouts up.

Question 14

What are sori? Describe the structures contained there.

Answer 14

Sori are clusters of sporangia on fern leaves.

Question 15

What is a fern sporangium composed of?

Answer 15

A stalk, annulus (thinner side that opens to release meiospores) and meiospores

Question 16

List the asexual forms of flowering plant reproduction

Answer 16

• Rhizomes
• Tubers
• Runners (stolons)
• Plantlets
• Bulbs
• Corms

Question 17

Describe asexual reproduction via rhizomes

Give an example of an organism that uses this

Answer 17

Underground stems called rhizomes produce adventitious roots that form an above ground shoot

Ex. Grasses

Question 18

Describe asexual reproduction via tubers

Give an example of an organism that uses this

Answer 18

Modified rhizomes, called tubers, form from special stem branches that grown down into the ground and buds on these will grow into new plants

Ex. potato

Question 19

Describe asexual reproduction via runners(stolons)

Give an example of an organism that uses this

Answer 19

Runners are horizontal stems. A node forms where a leaf normally would and adventitious roots form and go down into the soil

Ex. strawberries

Question 20

What is this structure? What are the parts of the structure? Identify this organism it came from.

Answer 20

This is the sporangium of Polytrichum sp., which consists of a cap (operculum), spores, and a stem (seta)

Question 21

Describe asexual reproduction via plantlets

Give an example of an organism that uses this

Answer 21

Miniature plants form on leaf margins, drop off and develop into new plants

Ex. Duckweed

Question 22

Describe asexual reproduction via bulbs

Give an example of an organism that uses this

Answer 22

Consists of short stem surrounded by fleshy leaves. Shoot grows in spring using nutrients from leaves

Ex. Onion

Question 23

Describe asexual reproduction via corms

Give an example of an organism that uses this

Answer 23

Similar to bulbs, but no storage leaves. Nutrients are in swollen stem.

Ex. Crocus

Question 24

What are the male and female parts on a flowering plant? What are the protective/pretty parts?

Answer 24

Male - stamen

Female - carpel or pistil

Protective - Perianth

Question 25

What are male and female sporangia in flowing plants otherwise referred to as?

Answer 25

Male = micro-sporangium Female = mega-sporangium

Question 26

Describe the outer structures of a typical flower (all but the carpel and it's contents).

Answer 26

**Sepals** are on the outside (green and leaf-like), with brightly coloured or smelly **petals** inside that. Inside those two are the **stamens**. Each stamen has **anther** suspended on **filament**. **Anther** is made up of one or more **microsporangia** where **pollen grains** are made (the multicellular haploid structures that eventually form the **male gametes**).

Question 27

Describe the inner structures (carpel and everything inside) of a typical flower

Answer 27

The **carpal** is the most central structure, with a modified leaf that produces **ovules**, composed of **stigma** (which recieves pollen), **style** (slender stalk for pollen), and **ovary** (with **ovules** inside). Ovules contain **megasporangium** which produces female gametes.

Question 28

Describe the male anther

Answer 28

The **anther** contains many **microsporocytes** which undergo meiosis to form **microspores**, which further divide mitotically to become a **dikaryotic pollen grain.** These two nuclei are a **generative nucleus** and a **tube nucleus. **

Question 29

What happens to a pollen grain once it is released?

Answer 29

The grain reaches the stigma, germinates, and the tube nucleus makes a **pollen tube** that pentrates the stigma, grows through the style, and reaches the ovary. During this process, the generative nucleus has divided to make two **sperm nuclei**. This trikaryotic structure is the male gametophyte.

Question 30

Describe the female gametophyte in a flowering plant

Answer 30

This **embryo sac** develops in **ovule** inside **ovary.** Each ovule has a **megasporangium** which produces a **megasporocyte** that undergoes meiosis to obtain four **haploid megaspores.** 3/4 disintegreate and the fourth divides mitotically three times. This creates the **mature female gametophyte**.

Question 31

Describe the pollination and fertilization process

Answer 31

Pollen reaches stigma, one sperm nuclei fuses with the egg nucleus to create a **zygote** and the other fuses with the two **polar nuclei** within the embryo sac to create the **endosperm nucleus**. This process is called **double fertilization**. The triploid endosperm nucleus nourishes the developing zygote, and the new ovule + zygote is termed a **seed**

Question 32

Describe seed development

Answer 32

Integument of ovule turns into **seed coat**, **endosperm** develops, **embryo** develops (as it does it absorbs endosperm, nutrients stored in **cotyledons**). The rest happens in five stages: Pro-embryo stage: zygote divides (basal cell present, suspensor pushes two-celled pro-embryo up) Globular stage: radially symmetrical Heart-shaped stage: Two cotyledons form heart shape Torpedo stage: Cotyledons elongate Mature embryo: Mature embryo has bent cotyledons attached

Question 33

Describe the parts of a seed

Answer 33

Integuments are **seed coat**, basal portion of embryo is **radicle**, middle portion is **hypocotyl**, part attached to cotyledons is **epicotyl**.

Question 34

What do we mean by **division of labour** within plants?

Answer 34

Each plant organ serves a specific purpose/has a certain job

Question 35

List each plant organ and the primary purpose of each

Answer 35

Leaves - Photosynthesis Stems - Assist leaves by moving them up high Roots - Absorb water/nutrients Cones/flowers - reproduction

Question 36

Plant cells form in rapidly dividing zones called \_\_\_\_\_\_\_\_\_, and two ___________ exist on any plant, one at the tip of _____________ and one at the tip of \_\_\_\_\_\_\_\_\_\_\_

Answer 36

Meristems, apical meristems, the above ground shoot, underground root

Question 37

Describe epidermal tissue

Answer 37

Principle surface tissue in young plants - **epidermis** Epidermal cells secrete **cuticle** (waxy, water-risistant layer)

Question 38

Describe the xylem

Answer 38

Xylem is used for support and transport of water/dissolved substances up the plant. Ferns only have **tracheid** cells, whereas flowering plants have **tracheids**, **vessel elements**, **parenchyma** (the only living cell in the xylem) and **sclerenchyma. **

Question 39

Describe the phloem

Answer 39

Main function is to conduct water and carbs up AND down the plant. Conducting elements are called **sieve elements** (arranged in formation - **sieve tube**), elongated cells with special porous areas called **sieve plates**. Closely associated parenchyma-like cells are called **companion cells.**

Question 40

Name and describe the fundamental tissues

Answer 40

**Parenchyma** - Most common, large cell walls, contain leucoplasts (starch storage) **Sclerenchyma** - Small, tough walls, often have lignin inside, structural support, found where plant is no longer growing **Collenchyma** - specialized for strcutural support, flexible/thikcness between parenchyma and sclerenchyma, supports still growing parts of plant

Question 41

Describe the phylum bryophyta

Answer 41

Plants have **rhizoids, stems,** and **leaves**. An outer **epidermis**, **storage cortex** of parenchyma cells, and a **central cylinder**.

Question 42

Describe phylum pfterophyta (ferns)

Answer 42

Have v**ascular tissue** and **true roots**. Stems grow horizontally underground and are called **rhizomes**, roots coming off those are **adventitious roots**. The **frond** is the leaf, the **stipe** is the stalk-like part. A **fiddlehead** is just a young frond. Ferns have epidermal cells that form a **cuticle**. **Chloroplasts** are present and there are **stomata** regulated by guard cells.

Question 43

What are the basic aspects of flowering plants? Describe each

Answer 43

* Nodes - leaves/buds branch from here * Internodes - parts of stem in between nodes * Terminal buds - tipds of stem/branches, enclose growing region * Axiallary/lateral buds - in axis of leaves, may give rise to lateral branched * Blade and petiole - specific parts of the leaf * Primary/secondary roots - primary is first root produced, everything else is secondary * Root tips - last few mm of root, new root mader here and water/minerals enter here

Question 44

Describe (in detail) the root

Answer 44

The root has three main functions: **absorption, anchorage, and food storage**. Older regions have a **cortex** filled with **parenchyma**. All root tissues come from **root apical meristem**, rapidly dividing region at tip of root. Has **root cap** for protection when moving through soil.

Question 45

What are the inner parts of a root?

Answer 45

The **epidermis** surrounds the root, followed by a thick **cortex** filled with **parenchyma** (**leucoplasts** present). The inner layer of the cortex is the **endodermis**. The **stele** is the central part of the root, with the **pericycle** on the outer layer, filles with **xylem** and **phloem**.

Question 46

Describe (in detail) the stem

Answer 46

The stem provides mechanical support and a path of cunduction between leaves/flowers/fruits and roots, and may also aid in water storage. Stems sometimes have photosynthetic tissue and **stomata**. There is an **epidermis** (and a **cuticle**), a **cortex** (with **parenchyma** and **collenchyma**), **pith**, **vascular bundle**, and **sclerenchyma** for support.

Question 47

Describe (in detail) the leaf

Answer 47

The primary function of the leaf is photosynthesis. The outermost layer is the **epidermis**, the interior is the **mesophyll** (**palisade mesophyll** in the upper region and **spongy mesophyll** in the lower), and of course v**ascular tissue** throughout the **spongy mesophyll**.

Question 48

What are some tricks xeric plants have come up with to stay alive?

Answer 48

* Succulence - Store water in fleshy leaves/stems/roots, undertake CAM photosynthesis * Drough tolerance and/or evasion - Microphylly (trait that causes smaller leaves), broader leaf surfaces, produce leaves only during cool or rainy seasons, have leaf orientation or colour that reduced the effect of the sun (vertical stems, lighter coloured vegitation = higher reflectance of the sun's rays

Question 49

Describe hydrophytic plants

Answer 49

Little or no mechanical strengthening (water holds the plant up), no external protective tissues (water is right there to absorb nutrients from), root function is mostly anchorage and no so much absorption, specialized leaf shapes and air filled cavities to provide an internal atmosphere. Ex. lily, duckweed

Question 50

What is this a picture of?

Answer 50

Moss protonema

Question 51

Identify this structure. Where are the reproductive structures within it? What are they called?

Answer 51

This is a prothallus - mature gametophyte in ferns. The **archegonia** are near the middle and the **antheridia** are near the ends.

Question 52

Identify this structure and the structures within

Answer 52

This is a cross section of a sorus (on a fern). The large bulbs are **sporangium**, the lined parts around them are **annulus**, and within the sporangium are **spores**

Question 53

Identify this organism. What stage is it in?

Answer 53

*Capsella* embryo in torpedo stage

Question 54

Identify this organism. What stage is it in?

Answer 54

*Capsella* - mature embryo

Question 55

What type of tissue is this? What type of cell?

Answer 55

Fundamental tissue. Collenchyma

Question 56

What type of tissue is this? What type of cell?

Answer 56

Fundamental tissue. Parenchyma

Question 57

What type of tissue is this? What type of cell?

Answer 57

Fundamental tissue. Sclerenchyma

Question 58

What is this? Are you able to recognize the different cells and structures within it?

Answer 58

It is a cross section of a moss stem. The middle circle is the **central cylinder**, the cells on the shell are the **epidermis**, and everything in between is the **cortex**. The tails are leaves.

Question 59

What is this structure? Do you recognize parts of it?

Answer 59

This is a cross section of a fern frond. The dark outer layer is the **epidermis** and the **cuticle**, the circles are **vascular bundles**, the large white bundles are **stoma**, and everything else is **mesophyll**

Question 60

What are the different types of roots? Describe them

Answer 60

Tap roots - Prominant primary root directly downaward with smaller lateral roots Fibrous roots - Many long slender roots with secondary and tertiary roots Adventitious - Aride from organ in plant, NOT primary root

Question 61

Identify this organism and important structures within it

Answer 61

This is the stem of *medicago sp.* The bundles along the edges are **xylem** and **phloem**, the middle area is the **pith**, the outer blue line is the **epidermis** and the purple line close to it is **parenchyma cells**. The area between the vascular bundles and the epidermis is filled with **parenchyma**

Question 62

Identify this organism. Note the Epidermic, cortex, endodermis, and stele.

Answer 62

*Ranunculus sp.*

Question 63

Identify this organism, this structure and the little structures inside.

Answer 63

*Lilium sp.* leaf The white outer layer is the **epidermis** (and **cuticle**), the long green top layer is the **palisade mesophyll**, the circular portion in the middle is a v**ascular bundle**, the small purple opening at the bottom of the leaf is a **stomata** and it's **guard cells**, and the random green bits in between are **spongy mesophyll**