Structure And Transport Of Flowering Plant

Question 1

What are the main functions of the root?

Answer 1

1. Anchor the plant in the ground, 2. Absorb water and minerals from the soil, 3. Sometimes store food, 4. Transport water and minerals to the rest of the plant.

Question 2

What are the two types of roots?

Answer 2

1. Fibrous roots: Many equal-sized roots from the stem base (e.g., grass), 2. Tap roots: One main root growing from the radicle (e.g., carrot).

Question 3

What occurs in the differentiation zone of a root?

Answer 3

Cells develop or differentiate into dermal, vascular, or ground tissue.

Question 4

What is the main function of the meristematic zone in a root?

Answer 4

Rapid cell division by mitosis.

Question 5

What are the primary functions of the stem?

Answer 5

1. Transport water, minerals from roots to plant parts and food from leaves to other parts, 2. Support leaves, buds, and flowers, 3. Sometimes store food, e.g., potato.

Question 6

What is a bud, and what are the types of buds?

Answer 6

A bud is an undeveloped shoot responsible for growth. Types: Apical buds (at the tip, cause upward growth) and Lateral buds (cause outward growth, producing side shoots and branches).

Question 7

What are the main functions of the leaf?

Answer 7

1. Make food by photosynthesis, 2. Exchange gases, 3. Transpiration, 4. Sometimes store food (e.g., lettuce, spinach, cabbage).

Question 8

What is the function of dermal tissue in plants?

Answer 8

Protection. In roots, it helps absorb water and minerals, often covered by a waxy cuticle on leaves.

Question 9

What is the function of ground tissue in plants?

Answer 9

Storage, photosynthesis, strength, and support.

Question 10

What are the two types of cells in xylem tissue?

Answer 10

1. Xylem tracheids: Long, tapered cells, overlap with pits, allow sideways water movement, 2. Xylem vessels: Elongated cells with no end walls, continuous tube, wider than tracheids, more efficient, contain side-wall pits.

Question 11

What is phloem tissue composed of, and what is its main function?

Answer 11

Phloem sieve tubes and companion cells; phloem transports food through translocation.

Question 12

List the differences between monocots and dicots.

Answer 12

Monocots: One cotyledon, scattered vascular bundles, parallel leaf veins, flower parts in multiples of 3, fibrous roots (e.g., grasses). Dicots: Two cotyledons, vascular bundles in a ring, netted leaf veins, flower parts in multiples of 4 or 5, tap roots (e.g., roses, dandelions).

Question 13

Describe the path of water transport in a flowering plant.

Answer 13

Root hairs → ground tissue → xylem → ground tissue → air space → stoma → atmosphere.

Question 14

What is transpiration?

Answer 14

The loss of water by evaporation from the surface of a leaf.

Question 15

What causes root pressure in plants?

Answer 15

The continuous build-up of water in the xylem.

Question 16

How does mineral uptake occur in plants?

Answer 16

Minerals (e.g., calcium, magnesium) enter roots dissolved in water by diffusion, then active transport if needed, and are transported in xylem.

Question 17

What role do stomata play in gaseous exchange?

Answer 17

They open during the day to allow CO2 in for photosynthesis and close at night to reduce water loss.

Question 18

What is a modified root? Give an example.

Answer 18

A root adapted for food storage, e.g., carrot.

Question 19

What is a modified stem? Give an example.

Answer 19

A stem adapted for storage, e.g., potato stem tubers.

Question 20

Describe the longitudinal sections/zones of a root and their functions.

Answer 20

1. Differentiation zone: Cells develop or differentiate into dermal, vascular, or ground tissue, 2. Elongation zone: Cells increase in size and elongate, 3. Meristematic zone: Rapid cell division by mitosis, 4. Protection zone: Protects the growing root tip.

Question 21

What is the shoot system of a flowering plant composed of?

Answer 21

An upright stem bearing buds, leaves, and flowers.

Question 22

Describe the structure of a leaf.

Answer 22

Lamina (flattened blade), Petiole (attaches leaf to stem), Sessile (leaves without petiole), Veins contain vascular tissue.

Question 23

What are the two types of leaf venation? Give examples.

Answer 23

1. Netted: Veins form a net-like pattern, e.g.rose,
2. Parallel: Veins run parallel, e.g., grass.

Question 24

What are the three main types of tissues in plants, and where do they develop from?

Answer 24

All develop from meristematic tissue. Types: 1. Dermal (outer covering), 2. Ground (inside the plant), 3. Vascular (transport).

Question 25

What substance strengthens xylem cells, and what pattern does it form?

Answer 25

Lignin strengthens xylem cells, often forming spiral or other patterns.

Question 26

Describe the structure and function of sieve tube cells in phloem.

Answer 26

Long, cylindrical cells stacked end-to-end, transport food, have sieve plates with pores, lack nucleus and lignin.

Question 27

What is the role of companion cells in phloem?

Answer 27

They control the activities of sieve tube cells and themselves, have a nucleus, and lack lignin.

Question 28

How do root hairs adapt for water absorption?

Answer 28

They are numerous, have thin walls, and a large surface area.

Question 29

How is water loss controlled in a leaf?

Answer 29

Through the opening and closing of stomata and the presence of a waxy cuticle.

Question 30

Who discovered the cohesion-tension model?

Answer 30

Irish scientists Dixon and Joly.

Question 31

Explain the cohesion-tension model for water transport.

Answer 31

Water’s cohesive (molecules stick together) and adhesive (molecules stick to xylem walls) properties create a continuous water column, pulled by transpiration.

Question 32

Explain the cohesion-tension model for water transport.

Answer 32

Water’s cohesive (molecules stick together) and adhesive (molecules stick to xylem walls) properties create a continuous water column, pulled by transpiration.

Question 33

How do day and night affect water transport in a plant?

Answer 33

Day: Xylem narrows as water is pulled by transpiration. Night: Xylem returns to original shape as no transpiration occurs.

Question 34

How do day and night affect water transport in a plant?

Answer 34

Day: Xylem narrows as water is pulled by transpiration. Night: Xylem returns to original shape as no transpiration occurs.

Question 35

What is translocation?

Answer 35

The transport of food in phloem tissue,

Question 36

Describe the adaptations for gaseous exchange in plants.

Answer 36

Adaptations for exchange include flat leaves, numerous stomata, and loosely arranged ground tissue with air spaces.

Question 37

Why might stomata close during the day?

Answer 37

If the plant has lost too much water or temperatures are too high.

Question 38

Describe the opening of stomata in terms of ion and water movement.

Answer 38

Photosynthesis lowers CO₂, potassium ions enter guard cells, water follows by osmosis, causing cells to swell and open stoma.

Question 39

Describe the closing of stomata.

Answer 39

At night, CO₂ builds up in guard cells, potassium ions leave, water exits, causing guard cells to shrink and close stoma.

Question 40

Give examples of modified leaves.

Answer 40

Bulbs like onions, garlic, which store food.

Question 41

What are modified petioles? Provide examples.

Answer 41

Swollen petioles storing food, e.g., celery,