Tag: modes of reproduction

Questions Related to modes of reproduction

Life cycle of Saccharomyces cerevisiae is 

botany modes of reproduction alternation of generation in angiosperms alternation of generation angiosperms

  1. Haplontic

  2. Diplontic

  3. Haplodiplontic

  4. None of the above

Show answer
Correct Option: C
Explanation:

Three types of life cycle patterns are seen in the Saccharomyces (yeasts).

(i)         Haplobiontic life cycle (Saccharomyces octopus)

(ii)        Diplobiontic life cycle (Saccharomyces ludwigii)

(iii)       Haplodiplontic life cycle (Saccharomyces cerevisiae)

The correct option is C.

Comparable to angiosperms which of the following alga exhibits diplontic life cycle?

botany modes of reproduction alternation of generation in angiosperms alternation of generation angiosperms

  1. Spirogyra

  2. Ectocarpus

  3. Fucus

  4. Polysiphonia

Show answer
Correct Option: C
Explanation:

  • Fucus (rockweed) is a type of brown alga and it displays the diploid life history. 
  • The zygote becomes the embryo and develops into the mature Fucus. 
  • The receptacles are reproductive branches and so contain many cavities with external pores. These pores contain antheridia (male) and oogonia (female)
  • The correct option is C.

Which one of the following shows the last diploid stage in the life cycle of angiosperms?

botany modes of reproduction alternation of generation in angiosperms alternation of generation angiosperms

  1. Microspore mother cell

  2. Zygote

  3. Nucellus

  4. Pollen grain

Show answer
Correct Option: A
Explanation:
A. Microspore mother cell or MMC is the diploid germ cell which forms microspores (pollen) by the process of microsporogenesis.
B. Zygote is the diploid structure formed by the fusion of male and female gametes.
C. Nucellus is the central part of ovule in which embryo is present. It is triploid.
D. Pollen grain or microspore is the haploid male gamete.
In the life cycle of angiosperms, zygote gives rise to a complete plant. The plant has germ cells which are diploid and produce gametes. The gametes then fuse to form a zygote. Hence, microspore mother cell is the last diploid stage because after that, haploid gametes are formed.
So, the correct answer is 'Microspore mother cell'.

Which of the statements regarding haplontic life cycle is incorrect?

botany modes of reproduction alternation of generation in angiosperms alternation of generation angiosperms

  1. Sporophytic generation is represented only by the one-celled zygote.

  2. There is no free-living sporophyte.

  3. Mitosis in the zygote results in the formation of haploid spores.

  4. The haploid spores divide mitotically and form the gametophyte.

Show answer
Correct Option: C
Explanation:

In a haplontic life cycle, the plant body is a gametophyte and dominant a dominant phase. The reproductive cell undergo mitosis to form gametes that are haploid, the gametic fusion results in a diploid zygote, which undergoes meiosis to form haploid spores.

So, the correct answer is 'Mitosis in the zygote results in the formation of haploid spores.'

Which one of the following has haplontic life cycle ?

botany modes of reproduction alternation of generation in angiosperms alternation of generation angiosperms

  1. Wheat

  2. Funaria

  3. Polytrichum

  4. Ustilago

Show answer
Correct Option: D
Explanation:

Ustilago is a genus of around 200 smut fungi parasitic on the grasses. In the haplontic life cycle, the haploid stage is multicellular whereas the diploid stage is a single cellular. The zygote undergoes meiosis to form the haploid spores. Each spore germinates are being divided to form gametophyte. The other three are not having this life cycle.

So, the correct answer is option D.

Haplo-diplontic life cycle is observed in how many of the following plants.
Pinus, Sphagnum, Polytrichum, Polysiphonia, Dryopteris, Riccia, Marchantis, Pteris, Selaginella, Ectocarpous, Volvox.

botany modes of reproduction alternation of generation in angiosperms alternation of generation angiosperms

  1. $6$

  2. $7$

  3. $8$

  4. $9$

Show answer
Correct Option: C
Explanation:

Haplo-Diplontic life cycle observed in 8 in following plants. This life cycle present only in Bryophytes and pteridophytes. So, sphagum, polytrichum, marchantis and riccia belongs to Bryophyta and selaginella, pteris, dryopteris and polysiphonia belongs to pteridophyta. That's why they consists Haplo-Diplontic life cylcle. 

A diploid parent plant body produces _______ gametes and a haploid parent plant body produces _________ gametes.

botany modes of reproduction alternation of generation in angiosperms alternation of generation angiosperms

  1. Diploid, haploid

  2. Haploid, diploid

  3. Diploid, diploid

  4. Haploid, haploid

Show answer
Correct Option: D
Explanation:
A diploid parent plant body produces haploid gametes (by reductional division) and a haploid parent plant body produces haploid gametes (by equational division). As the gametes are to be haploid since after union they will re-establish the ploidy level similar to the parent generation.
So, the correct answer is 'Haploid, haploid'.

Monocarpic plants are those which ________________.

biology reproduction in organisms sexual reproduction in organisms sexual reproduction & its importance modes of reproduction

  1. bear flowers with one ovary

  2. flower once and die

  3. bear only one flower

  4. all of the above.

Show answer
Correct Option: B
Explanation:

Monocarpic plants are those that flowers once during their Iife time, set seeds and then die, e.g.,bamboos.

Read the following statements about the reproductive cycles in mammals and select the correct ones.
(i) Oestrous cycle occurs in primate mammals.
(ii) In species with oestrous cycle, females are generally sexually active during oestrous phase.
(iii) Both the cycles show monthly recurrence.

botany modes of reproduction sexual reproduction in organisms sexual reproduction & its importance reproduction in organisms

  1. (i) and (ii)

  2. (ii) and (iii)

  3. (ii) only

  4. (i), (ii) and (iii)

Show answer
Correct Option: C
Explanation:

Oestrous cycle occur in non-primates such as cows, dogs, etc. Menstrual cycle occurs in primates only. Menstrual cycle shows monthly recurrence but oestrous cycle does not.

So, the correct answer is '(ii) only

Oestrous cycle is reported in

botany modes of reproduction sexual reproduction in organisms sexual reproduction & its importance reproduction in organisms

  1. Cows and sheep

  2. Humans and monkeys

  3. Chimpanzees and gorillas

  4. None of these

Show answer
Correct Option: A
Explanation:
The females of placental mammals exhibit cyclical changes in the activities of ovaries and accessory ducts as well as hormone during the reproductive phase.
-In non-primate mammals like cows, sheep, deer, dog, tiger, etc., such cyclical changes during reproduction are called oestrus cycle whereas in primates ( monkey, apes and humans)  such cyclical changes are called Menstrual cycle.
So, the correct answer is 'Option A- Cows and sheep'.