NEET biology

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Question
CBSEENBI11025486

Select the wrong statement.

  • Isogametes are similar in structure, function and behaviour

  • Anisogametes differ either in structure, function and behaviour

  • In oomycetes female gamete is smaller and motile, while male gamete is larger and non-motile

  • Chlamydomonas exhibits both isogamy and anisogamy and Fucus shows oogamy

Solution

C.

In oomycetes female gamete is smaller and motile, while male gamete is larger and non-motile

Oomycetes or egg fungus include water moulds, white rusts and downy mildews. In these, female gamete is smaller and motile, whereas male gamete is larger and non-motile. 

Isogametes are found in algae like Ulothrix, Chlamydomonas, Spirogyra, etc., which are similar in structure, function and behaviour.

Anisogametes are found in Chlamydomonas in which one gamete is larger and non-motile and the other one is motile and smaller.

Oogamy is the fusion of non-motile egg with motile sperm. The gametes, differ both morphologically as well as physiologically. It occurs in Chlamydomonas, Fucus Chara, Volvox, etc.

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Question
CBSEENBI11025487

Which one of the following is not a correct statement?

  • Herbarium houses dried, pressed and preserved plant specimens

  • Botanical gardens have collection of living plants for reference

  • A museum has collection of photographs of plants and animals

  • Key is a taxonomic aid for identification of specimens

Solution

C.

A museum has collection of photographs of plants and animals

Museums have collection of preserved plants and animal specimens for study and reference specimens are preserved in the containers in preservative solutions.

Herbarium is a store house at collected plant specimens that are dried, pressed and preserved on sheets.

Botanical gardens have collection of living plants for reference.

Key is a taxonomic aid for identification of plants and animals based on the similarities and dissimilarities.

Question
CBSEENBI11025488

lsogamous condition with non-flagellated gametes is found in

  • Chlamydomonas

  • Spirogyra

  • Volvox

  • Fucus

Solution

B.

Spirogyra

lsogamy is found in Spirogyra in which both gametes are non-motile.

In Chlamydomonas, all three conditions, isogamy anisogamy and oogamy are found. Both motile and non-motile gametes are found.

In Volvox and Fucus, oogamy is present, where non-motile egg fuses with motile sperm.

Question
CBSEENBI11025489

Besides paddy fields, cyanobacteria are also found inside vegetative part of

  • Pinus

  • Cycas

  • Equisetum

  • Psilotum

Solution

B.

Cycas

Cyanobacteria within the coralloid roots of Cycas are chemoheterotrophic and specifically adapted to life in symbiosis. Only a few species of cyanobacteria form associations with Cycas.

Pinus is a gymnosperm.

Equisetum belongs to vascular plants and to horse tail family.

Psilotum belongs to division- Pteridophyta and is a fern like plant.

Question
CBSEENBI11025490

Read the following statements (IV) and answer the question which follows them

I. In liverworts, mosses and ferns gametophytes are free living.

II. Gymnosperms and some ferns are heterospores.

III. Sexual reproduction in Fucus, Volvox and Albugo is oogamous.

IV. The sporophyte in liverworts is more elaborate than that in mosses.

How many of the above statements are correct?

  • One

  • Two

  • Three

  • Four

Solution

C.

Three

Statement I, II and III are correct.

In IV statement- sporophyte in mosses is more elaborate than in liverworts.

In V statement- Pinus is a monoecious plant, producing male and female cones every year.

In Marchantia, plant body is strictly dioecious and isomorphic. Sex organs are found in specialised sexual receptacles called anthridiophore and archegoniophore.