Plant Reproduction and Development

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Questions and Answers

What is the primary function of collenchyma in plants?

To store starch and other carbohydrates

To transport nutrients throughout the plant

To synthesize sugars and amino acids

To provide flexible structural support to actively growing parts (correct)

Which substances are conducted by phloem in plants?

Water and dissolved minerals

Oxygen and carbon dioxide

Lignin and cellulose

Sugars, amino acids, and hormones (correct)

What type of cells in xylem are responsible for water conduction in all vascular plants?

Tracheids with pits (correct)

Collenchyma cells for structural support

Vessel elements with perforations

Sieve-tube elements with sieve plates

What distinguishes vessel elements in angiosperms from other xylem cells?

They have perforations for enhanced water transport Signup and view all the answers

What component of sclerenchyma cells contributes to their toughness?

Lignin Signup and view all the answers

What happens immediately after pollination in the fertilization process?

The pollen grain germinates on the stigma. Signup and view all the answers

What is the role of the second sperm during double fertilization?

It contributes its nucleus to the endosperm. Signup and view all the answers

During seed development, what significant process occurs involving the zygote?

It divides to form the embryo. Signup and view all the answers

What occurs to the ovule after fertilization?

It begins developing into a seed. Signup and view all the answers

What triggers the growth and thickening of the ovary into a fruit?

Hormonal changes after fertilization. Signup and view all the answers

Which of the following components does the seed NOT provide?

Water Signup and view all the answers

What is the function of the fruit in relation to the seeds?

To protect seeds and aid in their dispersal. Signup and view all the answers

Which structure anchors the embryo to the parent plant during development?

Thread of cells Signup and view all the answers

What role do companion cells play in relation to sieve-tube elements?

They maintain the cytoplasm and plasma membrane. Signup and view all the answers

Which element is NOT mentioned as essential for the synthesis of biomolecules in plants?

Oxygen Signup and view all the answers

What factor significantly increases a plant's absorption efficiency?

Folded structures that increase surface area. Signup and view all the answers

Which function is primarily associated with the shoot system in plants?

Harvesting light and carbon dioxide. Signup and view all the answers

What is meant by 'phenotypic plasticity' in plants?

Ability to change structure in response to environmental factors. Signup and view all the answers

Which of the following statements about plant diversity is accurate?

It includes phenotypic plasticity and morphological diversity. Signup and view all the answers

What best describes the relationship between surface area and absorption in plants?

Large surface area enhances absorption rates. Signup and view all the answers

Which system in a plant architecture is responsible for taking in water and nutrients?

Root system. Signup and view all the answers

What is the main role of apical meristems in plant growth?

To lengthen roots and shoots Signup and view all the answers

What are the three zones of root growth behind the root cap?

Zone of differentiation, elongation, and division Signup and view all the answers

What does vascular cambium primarily produce?

Secondary xylem and secondary phloem Signup and view all the answers

How does secondary growth differ from primary growth in plants?

It thickens the diameter of stems and roots Signup and view all the answers

What type of cambium is responsible for producing cork cells?

Cork cambium Signup and view all the answers

What occurs as a result of removing the terminal bud from a plant?

Branching of lateral shoots Signup and view all the answers

Where is the vascular cambium located in the plant stem?

Between the primary xylem and primary phloem Signup and view all the answers

Which of the following is NOT a function of the cambium in plants?

Facilitating root elongation Signup and view all the answers

How much taller will the nail be placed at 2 meters above the ground in 10 years if the tree grows at a rate of 1 meter per year?

15 meters Signup and view all the answers

What critical function is lost when the bark around the entire circumference of a tree is stripped off?

Inability to transport sugars to the roots for survival Signup and view all the answers

What characteristic of a plant's shoot system is affected by the environment, such as lush versus dry habitats?

Phenotypic plasticity in size and shape Signup and view all the answers

Which statement best describes the adaptation of oak tree leaves to their environment?

Shade leaves maximize surface area for light absorption. Signup and view all the answers

What is one function of modified leaves in various plant species?

To attract pollinators for reproduction Signup and view all the answers

What allows tendrils to assist vines in climbing?

Modified leaves enabling attachment Signup and view all the answers

What physiological feature of the leaf assists in reducing water loss in sun-exposed areas?

Reduction of leaf size Signup and view all the answers

Which adaptation in the leaf structure primarily ensures maximum photosynthetic efficiency?

Large surface area for light absorption Signup and view all the answers

What is a consequence of phenotypic plasticity in leaf development in plants?

Variations in leaf morphology based on light exposure. Signup and view all the answers

What happens to the tree if the bark is stripped off completely?

Sugar transport will cease, leading to root death. Signup and view all the answers

Study Notes

Reproduction in Plants

Pollen grains germinate to produce pollen tubes that travel to the ovary
Double Fertilization: One sperm fertilizes the egg to form the zygote, the other fertilizes the central cell of the embryo sac to produce endosperm
Ovule becomes a Seed after fertilization
Endosperm provides food storage for the developing embryo
Seed coat forms near the end of maturation, allowing the seed to lose water and become dormant

Fruit Development

Ovary grows, thickens, and matures into a Fruit after fertilization
Fruits are mature ovaries that protect seeds and help with seed dispersal
Fruits can include other flower parts

Plant Tissues

Collenchyma: Provide flexible structural support for actively growing plant parts
Sclerenchyma: Contain tough, rigid lignin and cellulose to provide strength
Parenchyma: Typically have thin walls and can perform various functions, such as photosynthesis, storage, and secretion

Vascular Tissue

Xylem: Conducts water and dissolved nutrients from roots to shoots
Phloem: Conducts sugars, amino acids, and other substances from roots to shoots and vice versa

Vascular Tissue: Xylem

Contains tracheids (all vascular plants) with pits that help water transport
Vessel elements: In angiosperms, these cells have perforations that allow water transport
Vessel elements form chains to create tubes for water transport

Vascular Tissue: Phloem

Contains sieve-tube elements: Long, thin cells with perforated ends called sieve plates that facilitate transport
Companion Cells: Maintain the cytoplasm and plasma membrane of sieve-tube elements

Nutrient Acquisition

Photosynthesis requires light, CO2, and water
Plant growth also requires nutrients like nitrogen, phosphorus, potassium, and magnesium
Shoot System: Harvests light and CO2 from the atmosphere to produce sugars
Root System: Anchors the plant and takes in water and nutrients from the soil

Surface Area and Absorption

Folded structures increase surface area, leading to greater absorption

Nutrient Absorption and Surface Area

Both shoot and root systems function in absorption
Plants with large surface area are more efficient absorbers

Plant Diversity

Species Diversity: Morphological differences between plant species
Phenotypic Plasticity: Individual plants can exhibit different structures in response to the environment
Structural Variations: Herbs lack bark, woody stems exhibit vertical and outward growth

Primary Growth

Apical Meristems: Located at tips of roots and buds of shoots, responsible for primary growth (lengthening)
Root Cap: Protects the apical meristem of root tips
Root Growth Zones:
- Zone of Cell Division: Includes the apical meristem and dividing cells
- Zone of Elongation: Cells lengthen significantly
- Zone of Differentiation: Cells differentiate into dermal, vascular, and ground tissues

Secondary Growth

Increase in thickness of stems and roots
Lateral Meristems/Cambium: Found in a cylinder running the length of the root or stem
Two Types of Cambium:
- Vascular Cambium: Produces secondary xylem (wood) and secondary phloem (inner bark)
- Cork Cambium: Produces cork cells to form the outer bark

Wood Formation

Secondary xylem (wood) forms towards the interior of the stem
Secondary phloem forms towards the exterior of the stem
Newest growth occurs at the tips of branches

Plant Growth

Nail hammered into a tree trunk will remain at the same height as the tree grows taller
Stripping bark from the entire circumference of a tree can kill it because it removes phloem, which transports sugars necessary for root function

Shoot System Phenotypic Plasticity

Size and shape of the shoot system can vary in response to the environment
Tall shoot systems are favored in lush environments where light competition is high
Short, anchored stems are favored in dry, windblown habitats to minimize competition
Shoot systems can exhibit significant variations in size and shape

Modified Shoot Systems

Specialized shoot systems, like thorns, can be modified for various functions

Leaf Morphology

Photosynthesis is primarily carried out in leaves
Leaves have a large surface area to absorb photons and contribute to photosynthesis
Simple Leaves: Consist of a blade (expanded part) and a petiole (stalk)
Leaf arrangement on the stem can differ

Leaf Phenotypic Plasticity

Leaves can exhibit phenotypic plasticity in response to sunlight
Shade Leaves: Larger, broad, to maximize light absorption
Sun Leaves: Smaller, to reduce water loss in conditions of high light

Modified Leaves

Various leaves have been modified for specific functions:
- Onion bulbs store nutrients
- Succulent leaves store water
- Tendrils help vines climb
- Bright red leaves of poinsettias attract pollinators
- Pitcher plant leaves trap insects
- Cactus spines protect the stem

Modified Leaves and Flowers

Leaves can sometimes appear like flowers

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Description

Explore the fascinating processes of reproduction and development in plants. This quiz covers topics such as double fertilization, seed formation, and the maturation of fruits. Additionally, it addresses various plant tissues and their functions.