Q: What is the mode of nutrition in fungi?

Correct option -AExplanation for correct option -A●Fungi obtain nutrients from dead, organic matter that's why they are called saprophytes.● Fungi produce some kind of digestive enzymes for breaking down complex food into a simple form of food.

Q: What are the characteristic features of Euglenoids?

Some characteristic features of Euglenoids are as follows.• Euglenoids (such as Euglena) are unicellular protists commonly found in fresh water.• Instead of the cell wall, a protein-rich cell membrane known as pellicle is present.• They bear two flagella on the anterior end of the body.• A small light sensitive eye spot is present.• They contain photosynthetic pigments such as chlorophyll and can thus prepare their own food. However, in the absence of light, they behave similarly to heterotrophs by capturing other small aquatic organisms.• They have both plant and animal-like features, which makes them difficult to classify and hence they are called as connecting link between plants and animals.

Question 1

In the five kingdom classification, Chlamydomonas and Chlorella have been included in

Accepted Answer

In the five-kingdom classification, Chlamydomonas and Chlorella have been included in Kingdom Protista. Kingdom Protista includes unicellular eukaryotes. Kingdom Monera includes prokaryotes. Earlier, Chlamydomonas and Chlorella were placed in the kingdom Algae. However, according to R. H. Whittaker's classification, the classification depends not only on morphology or physiology but also on phylogeny.Thus, the correct answer is option A.

Question 2

How are viroids different from viruses?

Accepted Answer

Explanation:Viroids produce RNA whereas viruses produce proteins.Viroids consist of nucleic acid devoid of protein coat but viruses are&#10;composed of the nucleic acid coated with protein.In viruses, RNA can be copied in the nucleus or cytoplasm but in&#10;viroids, RNA or DNA molecules can be copied only in the nucleus.Viroids are simple in structure compared to the viruses.&#10;&#10;&#10;&#10;&#10;

Question 3

Give a comparative account of the classes of kingdom Fungi under the following:(i) Mode of nutrition(ii) Mode of reproduction

Accepted Answer

(A) Phycomycetes- This group of fungi includes members such as Rhizopus, Albugo, etc.(i) Mode of nutrition:They are obligate parasites on plants or are found on decaying matter such as wood.(ii) Mode of reproduction:Asexual reproduction takes place through motile zoospores or non-motile aplanospores produced endogenously in a sporangium.Sexual reproduction may be of isogamous, anisogamous, or oogamous type resulting in the formation of thick-walled zygospore.(B) Ascomycetes- This group of fungi includes members such as Penicillium, Aspergillus, Claviceps and Neurospora.(i) Mode of nutrition:They are sporophytic, decomposers, parasitic or coprophilous (growing on dung).(ii) Mode of reproduction:Asexual reproduction occurs through asexual spores produced exogenously, such as conidia produced on conidiophores.Sexual reproduction takes place through ascospores produced endogenously in sac-like asci and arranged inside ascocarps.(C) Basidiomycetes- This group of fungi includes members such as Ustilago, Agaricus and Puccinia.(i) Mode of nutrition:They grow as decomposers in soil or on logs and tree stumps. They also occur as parasites in plants causing diseases such as rusts and smuts.(ii) Mode of reproduction:Asexual reproduction takes place commonly through fragmentation. Asexual spores are absent.Sex organs are absent but sexual reproduction takes place through plasmogamy. It involves fusion of two different strains of hyphae. The resulting dikaryon gives rise to a basidium. Four basidiospores are produced inside a basidium. (D) Deuteromycetes- This group of fungi includes members such as Alternaria, Trichoderma and Colletotrichum.(i) Mode of nutrition:Some members are saprophytes while others are parasites. However, a large number act as decomposers of leaf litter.(ii) Mode of reproduction:Asexual reproduction is the only way of reproduction in Deuteromycetes, which occurs through asexual spores called as conidia.Sexual reproduction is absent in Deuteromycetes.

Question 4

What is the mode of nutrition in fungi?

Accepted Answer

Correct option -AExplanation for correct option -A&#9679;Fungi obtain nutrients from dead, organic matter that's why they are called saprophytes.&#9679; Fungi produce some kind of digestive enzymes for breaking down complex food into a simple form of food.

Question 5

Asexual and sexual spores found in fungi respectively are.

Accepted Answer

Name of sporesType of spores  Conidia & Zoospores Both are asexual spores Oospores & Ascospores Both are sexual spores Sporangiospores & basidiospores Asexual & sexual  Ascospores & basidiospores Both are sexual sporesSo, the correct answer is ' Sporangiospores & basidiospores

Question 6

Deuteromycetes are called as 'Imperfect fungi' as

Accepted Answer

The Fungi imperfecti or imperfect fungi, also known as Deuteromycota, are fungi which do not fit into the commonly established taxonomic classifications of fungi that are based on biological species concepts or morphological characteristics of sexual structures because their sexual form of reproduction has never been observed, hence the name imperfect fungi.Therefore, the correct answer is option C.

Question 7

Dikaryon formation occurs in

Accepted Answer

Sexual reproduction in Fungus involves the formation and the union of two gametes or their nuclei. Sexual reproduction is absent in the artificial group of fungi called Fungi imperfecti or Deuteromycetes. Depending upon the compatibility in sexual reproduction, fungi are of two types_ Homothallic and Heterothallic.In Heterothallic forms sexual reproduction involves fusion between two genetically different mating types. In Homothallic forms fusion occurs between genetically similar types. Fusion involves the union of cytoplasms as well as nuclei. The former is called Plasmogamy while the latter is called Karyogamy.In higher fungi, karyogamy is delayed and occurs just before meiosis. In the stage intervening between plasmogamy and karyogamy the cells often contain two nuclei or Dikaryons (n+n). Such cells are called dikaryotic cells. The phase is known as Dikaryophase which takes place in Ascomycetes and Basidiomycetes.In such fungi life cycle is completed in three phases instead of two_ Haplophase, Dikaryophase and Diplophase (2n). Meiosis occurs in diplophase.So the correct option is 'Ascomycetes and Basidiomycetes'.

Question 8

What are the characteristic features of Euglenoids?

Accepted Answer

Some characteristic features of Euglenoids are as follows.&#8226; Euglenoids (such as Euglena) are unicellular protists commonly found in fresh water.&#8226; Instead of the cell wall, a protein-rich cell membrane known as pellicle is present.&#8226; They bear two flagella on the anterior end of the body.&#8226; A small light sensitive eye spot is present.&#8226; They contain photosynthetic pigments such as chlorophyll and can thus prepare their own food. However, in the absence of light, they behave similarly to heterotrophs by capturing other small aquatic organisms.&#8226; They have both plant and animal-like features, which makes them difficult to classify and hence they are called as connecting link between plants and animals.

Question 9

Cell wall of fungi is made up of______

Accepted Answer

Cell wall is a tough, rigid layer that surrounds some types of cells. The cell wall is a characteristic feature to cells of plants, bacteria, fungi, algae, and some archaea. It is located outside the cell membrane. Cell wall composition varies from species to species and also depends on the developing stage of the organism. Protozoans and animals do not have a cell wall. In fungi, cell walls are made chitin.Hence the correct option is A.

Question 10

Factors responsible for the rapid spread of bread mould on slices of bread are:(i) large number of spores(ii) availability of moisture and nutrients in bread(iii) presence of tubular branched hypae(iv) formation of round shaped sporangia

Accepted Answer

The sporangium of bread mould releases a large number of spores that germinate on a suitable substratum to form the hyphae. Multiple hyphe branch and entangle to form a mat like structure called the mycelium. Fungi are saprophytes. Therefore, profuse growth is only possible in presence of a suitable substratum that supplies large amount of moisture and nutrients, like bread. So, the correct answer is '(i) and (ii)'