Biology Section 6 - Gymnosperms Flashcards

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Questions and Answers

What are gymnosperms?

They are early plants with pollen and seeds (cone-bearing plants).

Why are gymnosperms called cone-bearing plants?

Because they form their pollen and seeds in cones.

How do cone-bearing plants reproduce?

By the alteration of generations cycle.

What happens in the male cones?

The spores develop into pollen containing sperm cells. Signup and view all the answers

What happens in the female cones?

The sperm forms inside a bottle-shaped jacket of cells. Signup and view all the answers

How do cone-bearing plants spread their seeds?

Wind. Signup and view all the answers

When did cone-bearing plants first appear in the fossil record?

About 350 million years ago. Signup and view all the answers

When were cone-bearing plants the dominant land plant?

250 million years ago. Signup and view all the answers

What do cone-bearing plants contain?

Ovules, seeds, and pollen. Signup and view all the answers

What do cone-bearing plants NOT contain?

Flowers and fruits. Signup and view all the answers

What do cone-bearing plants do with their spores instead of shedding them like ferns do?

Cone-bearing plants retain their spores. Signup and view all the answers

What are cone-bearing plants' spores surrounded by?

Tissues of the parent plant, also known as the ovule. Signup and view all the answers

What does the spore form as it develops?

The egg - which will be fertilized to form the next generation of plant. Signup and view all the answers

Where do the ovules form in cone-bearing plants?

They form on the surface of the scales that make up the cones. Signup and view all the answers

What are the most important and numerous cone-bearing plants?

Conifers (e.g., pines, spruces, firs, and redwoods). Signup and view all the answers

What are the less numerous cone-bearing plants?

Cycads and ginkgos. Signup and view all the answers

What cone-bearing plants were the predominant land plants during the dinosaur ages?

Cycads and ginkgos. Signup and view all the answers

What are characteristics of conifers?

They include the world's largest plants, they don't release their spores, they use wind pollination, they were dominant in the dinosaur ages, and they're bisexual (have male and female cones). Signup and view all the answers

What do conifers provide to us in today's society?

They are used to produce paper. Signup and view all the answers

What are the three main types of conifers?

Pine trees, cycads, and ginkgos. Signup and view all the answers

What characteristics must conifers contain in order to use wind pollination?

They must contain large anthers and have a reduced amount of leaves. Signup and view all the answers

What percentage of lumber comes from conifers?

80%. Signup and view all the answers

What type of wood do conifers supply us with?

Softwood. Signup and view all the answers

Do all cone-bearing plants have separate male and female cones?

True Signup and view all the answers

How much of all harvested wood is used for the production of paper?

About half. Signup and view all the answers

What does paper consist of?

Purified cellulose pressed into sheets. Signup and view all the answers

Strands of conifers cover large parts of the earth's surface, but where do they particularly exist?

In the Northern latitudes. Signup and view all the answers

During the evolution of flowering plants, the ovule became surrounded by a layer of tissue, what is this tissue called?

The ovary. Signup and view all the answers

When did flowering plants evolve?

150 million years ago. Signup and view all the answers

When did flowering plants become numerous?

100 million years ago. Signup and view all the answers

Do flowering plants contain flowers AND fruits?

True Signup and view all the answers

What is a major advantage of flowering plants?

They are very well adapted to life on dry land. Signup and view all the answers

Study Notes

Gymnosperms Overview

Gymnosperms are early plant forms, known as cone-bearing plants, which produce pollen and seeds.
Reproduction occurs through an alteration of generations cycle.

Cone Structure and Function

Male cones develop spores that turn into pollen containing sperm cells.
Female cones provide a protective jacket of cells for developing sperm.

Seed Dispersal

Cone-bearing plants primarily spread their seeds via wind.

Fossil Record and Dominance

First appeared in the fossil record approximately 350 million years ago.
Dominated terrestrial ecosystems around 250 million years ago.

Plant Components

Gymnosperms possess ovules, seeds, and pollen but lack flowers and fruits.
They retain their spores, unlike ferns which shed them.

Development and Location of Ovules

Ovules form on the surfaces of scales in cones and develop into eggs for fertilization.

Types of Cone-bearing Plants

Most prevalent gymnosperms are conifers, including pines, spruces, firs, and redwoods.
Cycads and ginkgos are less numerous but were prevalent during the dinosaur era.

Characteristics of Conifers

Conifers include the largest plant species, retain spores, and rely on wind for pollination.
They are bisexual, possessing both male and female cones.

Economic Importance of Conifers

Conifers supply approximately 80% of global lumber and produce softwood.
They are crucial for paper production, with around half of harvested wood used for this purpose.

Adaptation and Distribution

Conifers thrive in northern latitudes, where they cover extensive regions.
Large anthers and reduced leaf sizes are characteristics that enhance wind pollination.

Evolutionary Context

Flowering plants emerged about 150 million years ago and became numerous 100 million years ago.
Flowering plants provide advantages such as adaptability to dry land and contain both flowers and fruits.

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Description

Test your knowledge on gymnosperms and their characteristics with these flashcards. Explore concepts such as reproduction, the significance of cones, and the definition of these unique plants. Perfect for biology students studying plant classifications.