reproduction

What are the main forms of plants that have evolved?

Algal ancestors, gymnosperms, angiosperms

Which types of plants are predominant in our environment?

Gymnosperms and angiosperms

What will the lecture cover regarding plant reproduction?

Changes over evolutionary time and main concepts

What are the two types of plant reproduction?

Sexual and asexual

What is involved in sexual reproduction in plants?

Alternation of generations resulting in two adult stages

Which plants were the first to produce seeds?

Gymnosperms

What do angiosperms use for pollination and seed spreading?

Flowers and fruits

How is asexual reproduction possible in plants?

Via apomixis and cellular cloning through mitosis

What are the advantages of asexual reproduction?

Genetic uniformity and propagation in the environment

Give examples of asexual reproduction in plants.

Rhizomes, palms, bulbs, plantlets

Which plants can reproduce asexually through bulbs?

Onions and garlic

How do orchids reproduce asexually?

Via structures

What is often necessary for clones to reproduce from?

Nutritional tissue

What are rhizomes?

Horizontal stems that give rise to shoots and spread roots

Give examples of plants that produce rhizomes.

Potatoes and taro

How do palms and bulbs reproduce asexually?

Using underground structures in the root system or stem

What are little plantlets and how do they contribute to asexual reproduction?

They are small plants that fall off and form new ones

What are the advantages of asexual reproduction in plants?

Generating individuals suited for the environment and propagating organisms

What is asexual reproduction in plants?

Reproduction without the involvement of gametes.

How do cam plants like Kalanchoe reproduce asexually?

Through the formation of tiny baby plants along the edges of every leaf.

What is the purpose of using asexual reproduction in horticulture?

To propagate plants.

How can forests be comprised entirely of cloned trees?

Through sprouts coming from the root system.

What is one example of a forest comprised of cloned trees?

A forest with sucker plants, considered one of the largest organisms on earth.

What are the disadvantages of asexual reproduction?

Genetically similar populations are susceptible to diseases.

What has human agricultural history experienced due to using clonal populations of plants?

Famines and lost crop varieties.

Do most plants reproduce sexually or asexually?

Most plants reproduce sexually.

What is the basis of sexual reproduction?

The process of meiosis, which enables genetic diversity in offspring.

What is mitosis?

A type of cell division used in asexual reproduction that produces genetically identical daughter cells.

What does sexual reproduction increase in a population?

Genetic diversity.

What does meiosis do to the amount of DNA in daughter cells?

Reduces it.

How many daughter cells are produced in meiosis?

Four.

What is the difference in chromosome number between parent cells and daughter cells in meiosis?

Daughter cells have half the number of chromosomes as the parent cell.

What type of cells are produced during sexual reproduction in eukaryotes?

Haploid cells that are genetically distinct from diploid parents.

What is the chromosome composition of haploid cells?

A single set of chromosomes (N).

What is the chromosome composition of diploid cells?

Pairs of chromosomes (2n) from each parent.

What is the relationship between meiosis and chromosome distribution?

Meiosis is involved in the distribution of chromosomes during sexual reproduction.

What is meiosis?

Process of distributing chromosomes from parent to daughter cells.

How many chromosomes do our body cells contain?

46 chromosomes, 23 from each parent.

What happens during meiosis?

Separation of mother and father copies of chromosomes in two division processes.

What is the result of meiosis?

Four unreplicated chromosome-containing daughter cells, each with one copy of each chromosome.

What is the role of meiosis in sexual reproduction?

Creation of sperm and egg cells with half the amount of DNA as parent cells.

What happens when sperm and egg fuse?

Creation of an adult organism with 46 chromosomes.

What type of reproduction is associated with mitosis?

Asexual reproduction.

What happens in mitosis?

A cell with two chromosomes replicates and divides into identical daughter cells.

What is the result of mitosis?

Two identical daughter cells.

How does meiosis differ from mitosis?

Meiosis involves multiple rounds of division and recombination of DNA, resulting in shuffled DNA and increased genetic diversity.

What is the result of meiosis?

Four daughter cells with shuffled DNA, leading to increased genetic diversity.

What type of cells does meiosis give rise to?

Cells involved in sexual reproduction, providing more opportunities for new organisms to appear.

What are gametes?

Cells that form a union to create another organism.

What happens when gametes combine?

Their DNA and chromosomes come together to produce a diploid set of chromosomes.

What is a zygote?

The result of the union of two gametes.

Why is understanding the formation of gametes and zygotes crucial?

It helps comprehend sexual reproduction.

How is the reproduction process of green algae different from terrestrial plants?

Due to the water environment they are in.

What is the life cycle of green algae?

Zygote undergoes meiosis to produce haploid spores, which grow into haploid adults.

What are gametangia?

Pockets within algal cells that produce gametes.

How are sperm and egg gametes produced in green algae?

In separate containers and fertilize each other for reproduction.

What happens to the systems of green algae's reproduction when organisms move onto land surfaces?

They change.

What is alternation of generations in land plants?

A process where there are two different adult individuals: sporophyte and gametophyte.

What is the multicellular haploid phase called in alternation of generations?

Gametophyte.

What does the multicellular diploid phase produce in alternation of generations?

Spores known as sporophytes.

How are the two phases in alternation of generations connected?

By distinct types of cells - gametes and spores.

What are sporophytes?

Adult plants that produce diploid spores.

How can haploid spores produced by sporophytes reproduce?

Via mitosis and grow into a new haploid parent plant called the gametophyte.

What is the gametophyte?

The haploid stage of the plant life cycle.

What does the gametophyte produce?

Haploid gametes.

What happens when the gametes fuse?

A new diploid zygote is formed.

What is the purpose of this cycle?

Sexual reproduction with varying DNA.