3B3 Structure and Functions of Plant Systems

Question 1

What is the main function of roots?

Answer 1

To anchor the plant while absorbing water and nutrients.

Roots secure plants in the soil and absorb water and essential minerals for growth. Some roots, like those of carrots, also store food.

Question 2

What structures increase a root’s surface area for absorption?

Answer 2

Root hairs

Root hairs enhance water and nutrient uptake by reaching into small soil spaces where roots cannot.

Question 3

True or False:

Roots are responsible for transporting food made in leaves to the rest of the plant.

Answer 3

False

Roots absorb water and minerals, but food transport is the role of the phloem in stems.

Question 4

Fill in the blank:

Water in plants is primarily transported through _______.

Answer 4

xylem

This carries water and minerals from roots to leaves, utilizing capillary action and transpiration pull.

Question 5

Which plant structure supports the plant and transports resources?

Answer 5

Stem

This structure contains the xylem and phloem, providing pathways for the movement of substances and structural support for leaves and flowers.

Question 6

True or False:

Phloem transports water from the roots to the leaves.

Answer 6

False

Phloem carries sugars and other organic nutrients, while xylem transports water and minerals.

Question 7

What is the primary function of leaves in vascular plants?

Answer 7

Photosynthesis

Leaves use chlorophyll to capture sunlight and produce glucose and oxygen, fueling the plant’s energy needs.

Question 8

What produces new xylem and phloem cells in stems?

Answer 8

Vascular cambium

The vascular cambium facilitates secondary growth, increasing the diameter of stems and roots in woody plants.

Question 9

What regulates gas exchange in leaves?

Answer 9

Stomata

They allow carbon dioxide to enter and oxygen to exit during photosynthesis, while also controlling water loss.

Question 10

Fill in the blank:

The stomata are controlled by _______ cells.

Answer 10

guard

Guard cells regulate the opening and closing of stomata based on environmental conditions like light and humidity.

Question 11

What is the role of the palisade mesophyll in leaves?

Answer 11

To carry out most of the plant’s photosynthesis.

Palisade mesophyll cells, located beneath the leaf’s upper epidermis, are packed with chloroplasts to maximize sunlight absorption.

Question 12

True or False:

The spongy mesophyll helps transport nutrients through the plant.

Answer 12

False

The spongy mesophyll facilitates gas exchange within the leaf but does not transport nutrients; that is handled by phloem tissue.

Question 13

Fill in the blank:

The _______ is a waxy layer that reduces water loss from leaves.

Answer 13

cuticle

It acts as a barrier to water evaporation and helps protect the plant from pathogens.

Question 14

Define:

Transpiration

Answer 14

The loss of water vapor from plant surfaces.

This water loss mainly occurs through stomata and creates a pull that aids in water transport via the xylem.

Question 15

What is the epidermis in plants?

Answer 15

The outermost layer of cells that protects the plant.

The epidermis forms a barrier against environmental damage and regulates gas and water exchange in leaves.

Question 16

True or False:

Xylem and phloem are found in vascular bundles.

Answer 16

True

Vascular bundles house both xylem and phloem, providing integrated pathways for transport in stems, roots, and leaves.

Question 17

How do xylem cells move water upward in a plant?

Answer 17

Through capillary action and transpiration pull.

Cohesion between water molecules and adhesion to xylem walls create an upward force, aided by water loss from stomata.

Question 18

What is asexual reproduction?

Answer 18

Reproduction without the fusion of gametes.

Asexual reproduction results in offspring that are genetically identical to the parent, as there is no exchange or combination of genetic material.

Question 19

What is budding in asexual reproduction?

Answer 19

A process where a new organism grows from the body of the parent.

Budding is common in organisms like yeast and hydra, where a small bud forms, develops, and eventually detaches to become a separate individual.

Question 20

True or False:

Asexual reproduction produces genetically identical offspring.

Answer 20

True

Asexual reproduction produces clones, meaning all offspring are genetically identical to the parent unless mutations occur.

Question 21

Fill in the blank:

In asexual reproduction, offspring arise from _____ parent(s).

Answer 21

one

A single parent is sufficient to produce offspring asexually, unlike sexual reproduction which requires two parents.

Question 22

What is sexual reproduction?

Answer 22

Reproduction involving the fusion of male and female gametes.

Sexual reproduction combines genetic material from two parents, resulting in offspring with genetic variation.

Question 23

What is pollination?

Answer 23

The transfer of pollen from the anther to the stigma.

Pollination can be facilitated by wind, water, or animals, and is essential for fertilization in flowering plants.

Question 24

What part of a flower produces pollen?

Answer 24

The anther.

The anther, located on the stamen, produces and releases pollen, which contains male gametes.

Question 25

# True or False: All flowers are **capable** of self-pollination.

Answer 25

False ## Footnote Some flowers rely on **cross-pollination**, requiring pollen transfer from another flower for fertilization.

Question 26

# Fill in the blank: The **female** reproductive part of a flower is called the \_\_\_\_\_\_\_.

Answer 26

pistil ## Footnote The **pistil** includes the stigma, style, and ovary, which are involved in receiving pollen and housing ovules for fertilization.

Question 27

What is the primary **function** of fruit in plants?

Answer 27

To **protect** seeds. ## Footnote Fruits develop from the ovary after fertilization, protecting the seeds inside and attracting animals to help spread them to new locations.

Question 28

How are seeds **formed** in plants?

Answer 28

Through **fertilization** of the ovule by pollen. ## Footnote The *ovule* develops into a seed after the male gamete from pollen fuses with the female gamete inside the ovary.

Question 29

# Fill in the blank: In plants, spores are **produced** by the process of \_\_\_\_\_\_\_.

Answer 29

meiosis ## Footnote **Meiosis** in plants produces haploid spores, which grow into gametophytes in non-flowering plants like mosses and ferns.

Question 30

What is the **difference** between self-pollination and cross-pollination?

Answer 30

* **Self-pollination** occurs within the same flower. * **Cross-pollination** occurs between different flowers. ## Footnote Cross-pollination increases genetic diversity, whereas self-pollination maintains the genetic consistency of a plant.

Question 31

How do seeds **aid** in plant reproduction?

Answer 31

By **growing** into new plants. ## Footnote *Seeds* contain an embryo and stored nutrients, enabling plants to reproduce and spread to new areas.

Question 32

# True or False: All seeds **require** water to germinate.

Answer 32

True ## Footnote **Water** activates enzymes and starts metabolic processes necessary for seed germination.

Question 33

What is **vegetative reproduction**?

Answer 33

A **form** of asexual reproduction using plant parts like stems or roots. ## Footnote Examples include runners in strawberries and tubers in potatoes, where new plants grow from existing structures.

Question 34

# Fill in the blanks: Spores are \_\_\_\_\_\_\_\_, whereas seeds are \_\_\_\_\_\_\_\_ and contain stored nutrients for growth.

Answer 34

unicellular; multicellular ## Footnote **Spores** lack an embryo and depend on the environment for development, while **seeds** have a protective coat and stored energy for germination.

Question 35

# True or False: Fruits **develop** from the ovary of a flower.

Answer 35

True ## Footnote After fertilization, the ovary of a flower matures into a fruit, which contains seeds.

Question 36

In non-flowering plants, where are spores **produced**?

Answer 36

In the sporangia. ## Footnote **Sporangia** release spores that grow into new plants when conditions are favorable.

Question 37

What is the **role of spores** in plant reproduction?

Answer 37

They are reproductive cells that develop **without** fertilization. ## Footnote They are common in *non-flowering plants* like ferns and mosses.

Question 38

How does photosynthesis **contribute** to plant growth?

Answer 38

It produces **glucose**, the main energy source for growth. ## Footnote Glucose is used in respiration to generate ATP, which powers cellular processes like cell division and elongation, leading to growth.

Question 39

What role does **chlorophyll** play in photosynthesis?

Answer 39

It **absorbs** sunlight. ## Footnote *Chlorophyll*, found in the chloroplasts, absorbs light energy from the sun, primarily in the blue and red wavelengths, and uses it to convert carbon dioxide and water into glucose.

Question 40

# True or False: Photosynthesis **only** occurs during the day when there is sunlight.

Answer 40

False ## Footnote Photosynthesis relies on light energy for the light-dependent reactions, which occur during the day. However, the light-independent reactions (Calvin cycle) can occur **both** during the day and at night, provided there is sufficient stored energy.

Question 41

# Fill in the blank: The **process** of photosynthesis occurs in the \_\_\_\_\_\_\_ of plant cells.

Answer 41

chloroplasts ## Footnote **Chloroplasts** contain chlorophyll, the pigment responsible for capturing light energy to drive photosynthesis.

Question 42

How does the amount of sunlight **affect** photosynthesis and plant growth?

Answer 42

More sunlight **increases** the rate of photosynthesis and promotes growth. ## Footnote Increased light energy boosts the photosynthesis rate, providing more glucose for energy and growth, but too much light can cause damage to plant cells.

Question 43

What **happens** to plant growth if photosynthesis is impaired?

Answer 43

It slows down or stops. ## Footnote Without enough glucose from photosynthesis, plants lack the energy required for cell division, elongation, and overall growth.

Question 44

# Fill in the blank: Photosynthesis **produces** \_\_\_\_\_\_\_ as a byproduct.

Answer 44

oxygen ## Footnote **Oxygen** is released into the atmosphere as a byproduct of photosynthesis, benefiting other organisms like animals that require oxygen for respiration.

Question 45

# True or False: Higher levels of carbon dioxide generally **increase** the rate of photosynthesis and growth.

Answer 45

True ## Footnote Higher levels can *enhance* photosynthesis, provided other conditions like light and water are optimal.

Question 46

What is a **stimulus**?

Answer 46

Any environmental change that **triggers** a response. ## Footnote It can be physical (e.g., light) or chemical (e.g., nutrients) and influences an organism's behavior or growth.

Question 47

What is the plant growth response to **light** called?

Answer 47

Phototropism ## Footnote This occurs when plants grow toward light to maximize photosynthesis.

Question 48

# Fill in the blank: The response of plant roots to **gravity** is called \_\_\_\_\_\_\_.

Answer 48

gravitropism ## Footnote Roots grow downward, and stems grow upward to anchor in soil and reach light.

Question 49

# True or False: Phototropism occurs when plants grow **away** from light.

Answer 49

False ## Footnote Plants typically grow **toward** light for optimal energy production.

Question 50

What is **hydrotropism**?

Answer 50

Growth of plant roots toward **moisture**. ## Footnote Roots grow toward water to ensure the plant receives enough hydration.

Question 51

What **type** of response is hydrotropism?

Answer 51

**Positive** response to water. ## Footnote Roots detect moisture gradients in soil and grow toward areas with higher water content.

Question 52

# True or False: Plant stems grow **downward** in response to gravity.

Answer 52

False ## Footnote Stems grow upward to reach light, demonstrating negative gravitropism.

Question 53

What is the **role** of auxins in phototropism?

Answer 53

It **causes** cell elongation on the shaded side, bending toward light. ## Footnote This allows plants to adjust their orientation for optimal light exposure.

Question 54

How do plants **respond** to temperature changes?

Answer 54

They may alter their growth rates or enter dormancy. ## Footnote *Extreme temperatures* can trigger protective mechanisms to prevent damage.

Question 55

# Fill in the blank: When temperatures are too high, plants may **close** their \_\_\_\_\_\_\_ to prevent water loss.

Answer 55

stomata ## Footnote This helps conserve water during high heat or drought conditions.

Question 56

# True or False: Plants can **detect** and respond to changes in temperature.

Answer 56

True ## Footnote Plants have mechanisms to sense temperature and adjust their growth accordingly.

Question 57

What is **thigmotropism**?

Answer 57

The growth response of plants to **touch**. ## Footnote Plants like vines wrap around supports to grow upward.

Question 58

# True or False: Thigmotropism **only** occurs in flowers.

Answer 58

False ## Footnote This behavior can be seen in vines, tendrils, and other climbing plants.

Question 59

# Fill in the blank: In response to cold temperatures, some plants **enter** \_\_\_\_\_\_\_\_ to conserve energy and avoid frost damage.

Answer 59

dormancy ## Footnote Dormancy helps plants conserve energy and protect themselves from frost damage.

Question 60

What is **negative phototropism**?

Answer 60

The growth of plants **away** from light. ## Footnote This is often seen in roots, which grow away from light to seek nutrients and water.