3B3 Structure and Functions of Plant Systems Flashcards
Explain how plant structures support growth and reproduction, with responses to stimuli and photosynthesis driving development and adaptation.
What is the main function of roots?
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.
What structures increase a root’s surface area for absorption?
Root hairs
Root hairs enhance water and nutrient uptake by reaching into small soil spaces where roots cannot.
True or False:
Roots are responsible for transporting food made in leaves to the rest of the plant.
False
Roots absorb water and minerals, but food transport is the role of the phloem in stems.
Fill in the blank:
Water in plants is primarily transported through _______.
xylem
This carries water and minerals from roots to leaves, utilizing capillary action and transpiration pull.
Which plant structure supports the plant and transports resources?
Stem
This structure contains the xylem and phloem, providing pathways for the movement of substances and structural support for leaves and flowers.
True or False:
Phloem transports water from the roots to the leaves.
False
Phloem carries sugars and other organic nutrients, while xylem transports water and minerals.
What is the primary function of leaves in vascular plants?
Photosynthesis
Leaves use chlorophyll to capture sunlight and produce glucose and oxygen, fueling the plant’s energy needs.
What produces new xylem and phloem cells in stems?
Vascular cambium
The vascular cambium facilitates secondary growth, increasing the diameter of stems and roots in woody plants.
What regulates gas exchange in leaves?
Stomata
They allow carbon dioxide to enter and oxygen to exit during photosynthesis, while also controlling water loss.
Fill in the blank:
The stomata are controlled by _______ cells.
guard
Guard cells regulate the opening and closing of stomata based on environmental conditions like light and humidity.
What is the role of the palisade mesophyll in leaves?
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.
True or False:
The spongy mesophyll helps transport nutrients through the plant.
False
The spongy mesophyll facilitates gas exchange within the leaf but does not transport nutrients; that is handled by phloem tissue.
Fill in the blank:
The _______ is a waxy layer that reduces water loss from leaves.
cuticle
It acts as a barrier to water evaporation and helps protect the plant from pathogens.
Define:
Transpiration
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.
What is the epidermis in plants?
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.
True or False:
Xylem and phloem are found in vascular bundles.
True
Vascular bundles house both xylem and phloem, providing integrated pathways for transport in stems, roots, and leaves.
How do xylem cells move water upward in a plant?
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.
What is asexual reproduction?
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.
What is budding in asexual reproduction?
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.
True or False:
Asexual reproduction produces genetically identical offspring.
True
Asexual reproduction produces clones, meaning all offspring are genetically identical to the parent unless mutations occur.
Fill in the blank:
In asexual reproduction, offspring arise from _____ parent(s).
one
A single parent is sufficient to produce offspring asexually, unlike sexual reproduction which requires two parents.
What is sexual reproduction?
Reproduction involving the fusion of male and female gametes.
Sexual reproduction combines genetic material from two parents, resulting in offspring with genetic variation.
What is pollination?
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.
What part of a flower produces pollen?
The anther.
The anther, located on the stamen, produces and releases pollen, which contains male gametes.
True or False:
All flowers are capable of self-pollination.
False
Some flowers rely on cross-pollination, requiring pollen transfer from another flower for fertilization.
Fill in the blank:
The female reproductive part of a flower is called the _______.
pistil
The pistil includes the stigma, style, and ovary, which are involved in receiving pollen and housing ovules for fertilization.
What is the primary function of fruit in plants?
To protect seeds.
Fruits develop from the ovary after fertilization, protecting the seeds inside and attracting animals to help spread them to new locations.
How are seeds formed in plants?
Through fertilization of the ovule by pollen.
The ovule develops into a seed after the male gamete from pollen fuses with the female gamete inside the ovary.
Fill in the blank:
In plants, spores are produced by the process of _______.
meiosis
Meiosis in plants produces haploid spores, which grow into gametophytes in non-flowering plants like mosses and ferns.
What is the difference between self-pollination and cross-pollination?
- Self-pollination occurs within the same flower.
- Cross-pollination occurs between different flowers.
Cross-pollination increases genetic diversity, whereas self-pollination maintains the genetic consistency of a plant.
How do seeds aid in plant reproduction?
By growing into new plants.
Seeds contain an embryo and stored nutrients, enabling plants to reproduce and spread to new areas.
True or False:
All seeds require water to germinate.
True
Water activates enzymes and starts metabolic processes necessary for seed germination.
What is vegetative reproduction?
A form of asexual reproduction using plant parts like stems or roots.
Examples include runners in strawberries and tubers in potatoes, where new plants grow from existing structures.
Fill in the blanks:
Spores are ________, whereas seeds are ________ and contain stored nutrients for growth.
unicellular; multicellular
Spores lack an embryo and depend on the environment for development, while seeds have a protective coat and stored energy for germination.
True or False:
Fruits develop from the ovary of a flower.
True
After fertilization, the ovary of a flower matures into a fruit, which contains seeds.
In non-flowering plants, where are spores produced?
In the sporangia.
Sporangia release spores that grow into new plants when conditions are favorable.
What is the role of spores in plant reproduction?
They are reproductive cells that develop without fertilization.
They are common in non-flowering plants like ferns and mosses.
How does photosynthesis contribute to plant growth?
It produces glucose, the main energy source for growth.
Glucose is used in respiration to generate ATP, which powers cellular processes like cell division and elongation, leading to growth.
What role does chlorophyll play in photosynthesis?
It absorbs sunlight.
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.
True or False:
Photosynthesis only occurs during the day when there is sunlight.
False
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.
Fill in the blank:
The process of photosynthesis occurs in the _______ of plant cells.
chloroplasts
Chloroplasts contain chlorophyll, the pigment responsible for capturing light energy to drive photosynthesis.
How does the amount of sunlight affect photosynthesis and plant growth?
More sunlight increases the rate of photosynthesis and promotes growth.
Increased light energy boosts the photosynthesis rate, providing more glucose for energy and growth, but too much light can cause damage to plant cells.
What happens to plant growth if photosynthesis is impaired?
It slows down or stops.
Without enough glucose from photosynthesis, plants lack the energy required for cell division, elongation, and overall growth.
Fill in the blank:
Photosynthesis produces _______ as a byproduct.
oxygen
Oxygen is released into the atmosphere as a byproduct of photosynthesis, benefiting other organisms like animals that require oxygen for respiration.
True or False:
Higher levels of carbon dioxide generally increase the rate of photosynthesis and growth.
True
Higher levels can enhance photosynthesis, provided other conditions like light and water are optimal.
What is a stimulus?
Any environmental change that triggers a response.
It can be physical (e.g., light) or chemical (e.g., nutrients) and influences an organism’s behavior or growth.
What is the plant growth response to light called?
Phototropism
This occurs when plants grow toward light to maximize photosynthesis.
Fill in the blank:
The response of plant roots to gravity is called _______.
gravitropism
Roots grow downward, and stems grow upward to anchor in soil and reach light.
True or False:
Phototropism occurs when plants grow away from light.
False
Plants typically grow toward light for optimal energy production.
What is hydrotropism?
Growth of plant roots toward moisture.
Roots grow toward water to ensure the plant receives enough hydration.
What type of response is hydrotropism?
Positive response to water.
Roots detect moisture gradients in soil and grow toward areas with higher water content.
True or False:
Plant stems grow downward in response to gravity.
False
Stems grow upward to reach light, demonstrating negative gravitropism.
What is the role of auxins in phototropism?
It causes cell elongation on the shaded side, bending toward light.
This allows plants to adjust their orientation for optimal light exposure.
How do plants respond to temperature changes?
They may alter their growth rates or enter dormancy.
Extreme temperatures can trigger protective mechanisms to prevent damage.
Fill in the blank:
When temperatures are too high, plants may close their _______ to prevent water loss.
stomata
This helps conserve water during high heat or drought conditions.
True or False:
Plants can detect and respond to changes in temperature.
True
Plants have mechanisms to sense temperature and adjust their growth accordingly.
What is thigmotropism?
The growth response of plants to touch.
Plants like vines wrap around supports to grow upward.
True or False:
Thigmotropism only occurs in flowers.
False
This behavior can be seen in vines, tendrils, and other climbing plants.
Fill in the blank:
In response to cold temperatures, some plants enter ________ to conserve energy and avoid frost damage.
dormancy
Dormancy helps plants conserve energy and protect themselves from frost damage.
What is negative phototropism?
The growth of plants away from light.
This is often seen in roots, which grow away from light to seek nutrients and water.
