Reproductive Structures of Flowers

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Questions and Answers

What is the correct sequence of events in a pollen sac?

sporangia → meiosis → two haploid cells → meiosis → two pollen grains per cell

microsporocyte → meiosis → microspores → mitosis → two haploid cells per pollen grain (correct)

pollen grain → meiosis → two generative cells → two tube cells per pollen grain

two haploid cells → meiosis → generative cell → tube cell-fertilization → pollen grain

What covers the young shoot and young root in a grass seed?

coleoptile; coleorhiza (correct)

hypocotyl; epicotyl

cotyledon; radicle

scutellum; radicle

What is the function of the megasporocyte in plant reproduction?

to produce 4 active megaspores through meiosis (correct)

to produce 1 active megaspore through mitosis

to produce 2 inactive megaspores through meiosis

to produce 8 nuclei through meiosis

What is the structure of an anther?

Structure A is described as intact, and B is the source of the microsporocyte Signup and view all the answers

What is the function of the microsporangia in an anther?

to produce the microsporocyte Signup and view all the answers

What is the location of the labeled structures in the featured specimen?

A is funiculus, B is the placenta Signup and view all the answers

What do pollen grains contain?

2 sperm nuclei and pollen tube Signup and view all the answers

What is the term for the process of meiosis in plant reproduction?

sporogenesis Signup and view all the answers

What structure inside the anther is responsible for nourishing the microspores?

Tapetum Signup and view all the answers

Which structure serves as the male gametophyte?

Pollen grain Signup and view all the answers

As a flower develops, which change is most likely to occur?

Microspores become pollen grains. Signup and view all the answers

Where and by which process are sperm cells formed in plants?

Mitosis in male gametophyte pollen tube Signup and view all the answers

Which of the following options is NOT haploid?

Microsporocytes Signup and view all the answers

Which of the following statements is true regarding spiked pollen?

Spiked pollen can be described as having different structural variations. Signup and view all the answers

If a flowering plant has a diploid number of 36, what would be the chromosome number in its endosperm?

36 Signup and view all the answers

Which statement is true about the embryo in relation to the seed structure?

The embryo is protected by the endosperm. Signup and view all the answers

What is the primary function of a megasporocyte in plant reproduction?

To develop into a female gametophyte Signup and view all the answers

Which structure within the pollen sac is responsible for the production of male gametophytes?

Microspores Signup and view all the answers

During meiosis in plant reproduction, what is the outcome of a single megasporocyte?

One functional megaspore and three non-functional spores Signup and view all the answers

What is the primary purpose of the embryo protective structures in seeds?

To prevent desiccation and provide mechanical protection Signup and view all the answers

Which part of the plant's life cycle is primarily responsible for gametophyte development?

Sporophyte phase Signup and view all the answers

What characteristic is typical of epigeal germination?

Cotyledons are the first to emerge from the soil Signup and view all the answers

Which statement about seed germination is accurate?

It necessitates moisture, temperature, oxygen, and a carbon dioxide source Signup and view all the answers

Which of the following statements about cotyledons in dicot seeds is NOT true?

They do not contain any food reserves Signup and view all the answers

Study Notes

Structure Relationships

Structure A is described as amoeboid in form with B being the epidermis.
Structure A maintains an intact condition while B serves as the source of the microsporocyte.
Structure A remains intact with B identified as the stomium of the anther.
Structure A is amoeboid, and B is part of the vascular bundle.

Pollen Sac Events

Sequence of events: microsporocyte → meiosis → microspores → mitosis → two haploid cells per pollen grain.

Grass Seed Embryo Protection

Grass seed embryos have two protective sheaths: coleoptile (covers the young shoot) and coleorhiza (covers the young root).

Megasporocytes and Megaspores

Megasporocytes, found in the gynoecium, undergo meiosis to produce four megaspores, of which one becomes active.
In flowering plants, the surviving megaspore undergoes mitosis to result in eight nuclei.

Pollen Grain Components

Pollen grains, derived from a microsporocyte within the microsporangia, contain two sperm nuclei and one polar nucleus.
The tapetum inside the anther nourishes the microspores.

Male Gametophytes

The microgametophyte and pollen grain are considered male gametophytes.

Flower Development

As flowers develop, microspores transition into pollen grains, while ovules mature into ovaries.

Sperm Cell Formation

Sperm cells are formed by mitosis in the male gametophyte within the pollen tube.

Haploid Structures

Tube nucleus and generative nucleus are haploid, while microsporocytes are diploid.

Pollen Characteristics

Presence of spiked, group formations, and characterized as pantoporate pollens.

Seed Structure and Chromosome Number

For flowering plants with a diploid chromosome number of 36, the endosperm chromosome number is 54 (triploid).
Seeds contain an embryo and do not require light for germination.

Seed Components and Germination

Corn seeds possess a scutellum, which separates them from other seeds.
Plumule is near the epicotyl, while the radicle is close to the hypocotyl.

Cotyledon Traits

Dicot seed cotyledons are the first to emerge, contain food reserves, and are embryonic leaves.

Germination Types

Epigeal germination occurs in specific seed types; identification is based on growth patterns.

Germination Conditions

Seeds require temperature, moisture, oxygen, food supply, and carbon dioxide for germination.

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Description

This quiz covers the structures involved in plant reproduction, including the anther, pollen, and ovules. Test your knowledge of these critical components of plant biology!