Plant Biology: Seeds and Ovules

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary function of an ovule after fertilization?

To produce a seed

To form a zygote (correct)

To support the stigma

To assist in pollen tube growth

Which of the following cells is NOT part of the female gametophyte structure?

Synergid cells

Antipodal cells

Egg cell

Male gamete (correct)

What occurs during meiosis in ovule formation?

Only one megaspore undergoes mitosis

The chromosome number is halved (correct)

The chromosome number doubles

Four diploid megaspores are produced

Which cell in the female gametophyte is believed to have an unknown function?

Antipodal cells Signup and view all the answers

Where are ovules located within a flower?

Within the ovary Signup and view all the answers

What is formed when a zygote develops?

An embryo Signup and view all the answers

What does the seed contain besides the plant embryo?

Food reserve Signup and view all the answers

Which process leads to the formation of four haploid megaspores?

Meiosis Signup and view all the answers

What occurs during double fertilization in angiosperms?

One male gamete fuses with the egg cell and another with polar nuclei. Signup and view all the answers

Which structure develops into a protective layer around the embryo and endosperm?

Ovule wall Signup and view all the answers

What is a key characteristic of albuminous seeds?

They contain a reserve of endosperm for the developing embryo. Signup and view all the answers

Which part of a seed is responsible for developing into the plant?

Embryo Signup and view all the answers

Which of the following is an example of a dicotyledonous seed?

Beans Signup and view all the answers

What is the function of the endosperm in a seed?

To store nutrients for the developing embryo. Signup and view all the answers

Which process involves the transfer of pollen from one flower to another?

Pollination Signup and view all the answers

In what type of germination do seeds like peas and beans store nutrients in their cotyledons?

Exalbuminous Signup and view all the answers

What is the primary role of seeds in the life cycle of a plant?

Reproduction Signup and view all the answers

Which condition is essential for the germination process of seeds?

Water Signup and view all the answers

What is the first stage of seed germination called?

Imbibition Signup and view all the answers

What role does temperature play in seed germination?

Activates metabolic processes Signup and view all the answers

Which factor does NOT affect seed germination?

Availability of shade Signup and view all the answers

What is dormancy in seeds primarily for?

To prevent premature germination Signup and view all the answers

Which of the following describes the role of the seed coat?

Protecting the embryo Signup and view all the answers

Which stage in germination involves the seed straightening out after emerging from the soil?

Epicotyl emergence Signup and view all the answers

Study Notes

Seed Definition

A seed is a fertilized ovule containing an embryo and a food reserve.
It is a mature, fertilized, integumented ovule.

Ovule Formation

Ovules are female reproductive structures in plants, crucial for seed production and the plant life cycle.
Ovules develop from specialized megaspore mother cells which undergo meiosis.
Meiosis reduces chromosome number by half, producing four haploid megaspores.
Typically, one megaspore survives and undergoes three mitotic divisions forming the embryo sac.
The embryo sac contains an egg cell and other cells involved in fertilization.

Ovule Structure

The female gametophyte consists of seven cells.
Egg cell: Fuses with pollen to form a zygote.
Synergid cells: Assist in pollen tube growth and fertilization.
Antipodal cells: Function unknown.
Central cell: Contains two polar nuclei.
Ovules are found within the flower's ovary.

Embryo Formation

Fertilization involves a pollen grain landing on the stigma, developing a pollen tube, and the male gamete fusing with the egg cell.
The fertilized egg (zygote) develops into an embryo, a miniature plant within the seed.
Specialized tissues form the seed coat and endosperm, providing nutrients for the embryo.

Seed Formation

Pollination is the transfer of pollen to the stigma.
Fertilization occurs when the pollen tube reaches the ovule and the male gametes fuse with the female gametes.
The ovule develops into a seed.
The ovary develops into the fruit enclosing the seeds.

Seed Germination

Seeds start to grow into a new plant following a period of dormancy.
Imbibition: Intake of water
Epicotyl or Hypocotyl emergence: Different germination types.
Factors affecting germination include seed quality, soil conditions, and competition.

Types of seeds

Based on Structure: Monocots (one cotyledon) and dicots (two cotyledons).
Based on Germination Patterns: Albuminous seeds (endosperm present), and exalbuminous seeds (no endosperm).
Importance of Seeds: Reproduction, dispersal, and food source for animals and humans.

Factors Affecting Germination

Seed quality (viability and dormancy).
Soil conditions (moisture, pH, nutrients)
Competition (presence of other plants).

Seed Structure

A typical seed consists of the embryo, endosperm, and seed coat.

Types of Germination

Epigeal: Cotyledons are raised above the ground surface.
Hypogeal: Cotyledons remain beneath the ground.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

This quiz covers the definitions and structures of seeds and ovules, their formation, and the processes involved in fertilization and embryo development in plants. Test your understanding of these vital components of the plant life cycle.