Quiz and Flashcards on Fungi, Lichen, Viruses

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

How are mature conidia of Penicillium dispersed?

By insects

By water

By animals

By wind (correct)

What is the name given to the perfect stage of Penicillium?

Genus Penicillium

Talaromyces (correct)

Antheridium

Form

In which genus are species with a sexual or perfect stage placed?

Mycobacterium

Talaromyces (correct)

Ascomycete

Penicillium

How does new mycelium form in Penicillium?

Migration on germ tube Signup and view all the answers

What are the male and female sex organs known as in Penicillium?

Antheridia and ascogonia Signup and view all the answers

Which species of Penicillium shows somatogamy?

P.brefeldianum Signup and view all the answers

What is the arrangement of conidia in a chain in Penicillium?

Basipetal Signup and view all the answers

What is the purpose of the basipetal arrangement of conidia in Penicillium?

Easy dispersal and nourishment Signup and view all the answers

How are mature conidia dispersed in Penicillium?

By air currents Signup and view all the answers

What is the structure of a Penicillium conidium?

Globose to ovoid with two-layered wall Signup and view all the answers

Which stage is more dominant in Penicillium compared to Aspergillus?

Conidial stage Signup and view all the answers

What happens as the conidial chain lengthens in Penicillium?

Connectives between older conidia break down Signup and view all the answers

What are the ultimate branches that bear tufts of flask-shaped sterigmata or phialides called in Penicillium?

Metulae Signup and view all the answers

In Penicillium thomii, what are the conidiophores like?

Unbranched Signup and view all the answers

What is the term used for the lower branches that support the metulae in Penicillium?

Rami Signup and view all the answers

What is the structure formed when many conidiophores aggregate to form a compound club-shaped fructification in Penicillium?

Coremium Signup and view all the answers

Where are the conidia formed within in Penicillium?

Slim tips of the flask-shaped phialides Signup and view all the answers

What happens to the phialide nucleus during the formation of conidia in Penicillium?

It migrates into the swollen tip Signup and view all the answers

Study Notes

Conidium Formation and Dispersal

The tip of the phialide swells and forms a conidium, which then elongates to form a chain of conidia in a basipetal arrangement.
The youngest conidium is closest to the tip of the sterigma, while the oldest conidium is furthest away.
This arrangement allows for easy dispersal of mature conidia and provides nourishment to younger conidia.
As the chain grows, connectives between older conidia break, allowing mature conidia to separate and disperse through air currents.

Characteristics of Conidia

Conidia are small, light, and dry, and have a pigmented spore wall differentiated into two layers: a thick, smooth or spiny outer exine and a thin inner intine.
Conidia are globose to ovoid in shape.

Germination of Conidia

Conidia germinate on a suitable substrate, with the nucleus dividing rapidly and a germ tube emerging.
All nuclei migrate to the germ tube, and septa form, leading to the development of new mycelium.

Sexual Reproduction in Penicillium

Sexual reproduction has been studied in some species of Penicillium, showing a gradual reduction in sexuality.
The process involves antheridia and ascogonia, which are negatively geotropic and arise singly from mycelial cells.
Some species are homothallic, while others (e.g., P.luteum) are heterothallic.

Conidiophores and Sterigmata

Conidiophores can be unbranched or branched, with primary, secondary, or tertiary branches.
Sterigmata are flask-shaped and bear conidia, and are arranged on metulae or at the tip of unbranched conidiophores.
The arrangement of conidiophores, metulae, and sterigmata resembles a small artist's brush.

Studying That Suits You

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

Description

This quiz discusses the formation of conidia in fungi, specifically focusing on the elongation and swelling of the phialide below the first conidium. It explains the process of conidium chain formation and the basipetal arrangement of conidia for easy dispersion.