Deuteromycetes

Question 1

conidiophore

Answer 1

-a specialized hyphae that may be simple, or branched, on which condia are formed

Question 2

Conidium

Answer 2

-a non-motile fungal mitospore not formed inside a sporangium

Question 3

Coelomycetes

Answer 3

• develop within host
• pressure of accumulating conidia ruptures host epidermis
• no asci, only conidia
• flask shaped and lined on inside with conidiophores
• deuteromycota/anamorph

Question 4

hyphomycetes

Answer 4

• molds
• exposed conidiophores on conidiomata
• lack closed fruit bodies
• usually solitary but can form aggregations

Question 5

Conidiogenesis

Answer 5

• process by which individual condia develop

- two basic patterns of development recognized (blastic and thallic)

Question 6

Blastic development pattern in conidiogenesis

Answer 6

-young conidium recognizable before it is cutt off by budding

Question 7

Thallic development in conidiogenesis

Answer 7

-cross wall laid down before differentiation of conidium begins

Question 8

Asexuality in anamorphs

Answer 8

• parasexual cycle

- need two types of nuclei in the mycelium of the fungus

Question 9

Parasexual cycle

Answer 9

• nuclear cycle wherein genes of haploid nuclei recombine without meiosis
• usually results in daughter nuclei having unequal number of chromosomes bc sis chromatids failed to separate

Question 10

Importance of parasexuality

Answer 10

• valuable tool for industrial mycologists to produce strains with desired combination of properties
• can occur at any time during normal, somatic growth

Question 11

Genetic variation in fungi

Answer 11

• mutations are basis of variation but depend on biology of organism
• any mutation will cause a change in fitness - beneficial short term
• cant accumulate mutations that are not of immediate selective value (disadvantage)

Question 12

Aneuploids

Answer 12

• result of sister chromatids not separating in parasexual cycle
• one daughter nucleus has one chromosome too many (2n+1)
• one daughter nucleus is lacking a chromosome (2n-1)
• theses are unstable and lose further chromosomes
• (2n+1) reverts to 2n, (2n-1) reverts to n

Question 13

steps of parasexual cycle

Answer 13

1) have 2 types of nuclei in mycelium
2) fusion of 2 nuclei (diploidization)
3) Restoration of diploid nuclei to haploid state (haploidization)

Question 14

What is involved in haploidization

Answer 14

-series of atypical and irregular mitotic divisions of the 2n nuclei