Chapter-1 Reproduction in Organisms

what is bio 

what is repro ?

Rose plants produce large, attractive bisexual flowers but they seldom
produce fruits. On the other hand a tomato plant produces plenty of
fruits though they have small flowers. Analyse the reasons for failure of
fruit formation in rose.

Differentiate between (a) oestrus and menstrual cycles; (b) ovipary and
vivipary. Cite an example for each type.

Although sexual reproduction is a long drawn, energy-intensive complex
form of reproduction, many groups of organisms in Kingdom Animalia
and Plantae prefer this mode of reproduction. Give atleast three reasons
for this.

Do all the gametes formed from a parent organism have the same genetic
composition (identical DNA copies of the parental genome)? Analyse the
situation with the background of gametogenesis and provide or give
suitable explanation.

Enumerate the differences between asexual and sexual reproduction.
Describe the types of asexual reproduction exhibited by unicellular
organisms.

Justify the statement ‘Vegetative reproduction is also a type of asexual
reproduction’.

Draw the sketches of a zoospore and a conidium. Mention two
dissimilarities between them and atleast one feature common to both
structures.

Suggest a possible explanation why the seeds in a pea pod are arranged
in a row, whereas those in tomato are scattered in the juicy pulp.

List the changes observed in an angiosperm flower subsequent to
pollination and fertilisation.

In a developing embryo, analyse the consequences if cell divisions are
not followed by cell differentiation.

'Fertilisation is not an obligatory event for fruit production in certains
plants'. Explain the statement.

'Fertilisation is not an obligato

Is it possible to consider vegetative propagation observed in certain plants
like Bryophyllum, water hyacinth, ginger etc., as a type of asexual
reproduction? Give two/three reasons.

With which type of reproduction do we associate the reduction division?
Analyse the reasons for it.

Honeybees produce their young ones only by sexual reproduction.
Inspite of this, in a colony of bees we find both haploid and diploid
individuals. Name the haploid and diploid individuals in the colony and
analyse the reasons behind their formation.

The number of taxa exhibiting asexual reproduction is drastically reduced
in higher plants (angiosperms) and higher animals (vertebrates) as
compared with lower groups of plants and animals. Analyse the possible
reasons for this situation.

In haploid organisms that undergo sexual reproduction, name the stage
in the life cycle when meiosis occurs. Give reasons for your answer.

What do the following parts of a flower develop into after fertilisation?
a. Ovary ______________
b. Ovules ______________

Match the organisms given in Column-’A’ with the vegetative propagules
given in column ‘B’.
Col. A                                                    Col. B
i. Bryophyllum                                      a) offset
ii. Agave                                              b) eyes
iii. Potato                                             c) leaf buds
iv. Water hyacinth                                d) bulbils

Which of the followings are monoecious and dioecious organisms.
a. Earthworm ______________
b. Chara ______________
c. Marchantia ______________
d. Cockroach ______________

Why do gametes produced in large numbers in organisms exhibit external
fertilisation?

Give reasons as to why cell division cannot be a type of reproduction in
multicellular organisms.

Is there a relationship between the size of an organism and its life span?
Give two examples in support of your answer.

Is the presence of large number of chromosomes in an organism a
hindrance to sexual reproduction? Justify your answer by giving suitable
reasons.

The probability of fruit set in a self-pollinated bisexual flower of a plant
is far greater than a dioecious plant. Explain.

Rearrange the following events of sexual reproduction in the sequence
in which they occur in a flowering plant:

Between an annual and a perennial plant, which one has a shorter
juvenile phase? Give one reason.

Although potato tuber is an underground part, it is considered as a
stem. Give two reasons.

Why do we refer to offspring formed by asexual method of reproduction
as clones?

Mention two inherent characteristics of Amoeba and yeast that enable
them to reproduce asexually.

Enlist the changes that occur post- fertilization in plants.

Give any three differences between asexual and sexual reproduction.

What happens during embryogenesis?

Why is syngamy a major event in sexual reproduction?

What are heterogametes? What do we call these gametes individually?

Mention the different stages of sexual reproduction.

What regulates the reproduction processes and the associated behavioural
expressions in organisms?

Define ‘oestrus’ and ‘menstrual’ cycles.

Why do hilly areas of Kerela, Karnataka and Tamil Nadu transform into blue
stretches that attracts many tourists?

Enlist the significance of reproduction.

How will you grow a banana and a ginger plant?

State the function of a vegetative propagule.

How do the following organisms reproduce: Paramoecium and Penicillium?

Which individuals can be termed as clones?

What represents the life span of an organism?

Why are offspring of oviparous animals at a greater risk as compared to offspring of viviparous animals?

Examine a few flowers of any cucurbit plant and try to identify the staminate and pistillate flowers. Do you know any other plant that bears unisexual flowers?

What is a bisexual flower? Collect five bisexual flowers from your neighborhood and with the help of your teacher find out their common and scientific names.

Describe the post-fertilization changes in a flower.

Differentiate between gametogenesis from embryogenesis.

Differentiate between a zoospore and a zygote.

Define external fertilization. Mention its disadvantages.

Identify each part in a flowering plant and write whether it is haploid (n) or diploid (2n).

(a) Ovary ———————————

(b) Anther ———————————

(c) Egg ———————————

(d) Pollen ———————————

(e) Male gamete ———————————

(f ) Zygote ———————————

Explain why meiosis and gametogenesis are always interlinked?

Higher organisms have resorted to sexual reproduction in spite of its complexity. Why?

Define

(a) Juvenile phase,

(b) Reproductive phase,

(c) Senescent phase.

What is vegetative propagation? Give two suitable examples.

Distinguish between asexual and sexual reproduction. Why is vegetative reproduction also considered as a type of asexual reproduction?

How does the progeny formed from asexual reproduction differ from those formed by sexual reproduction?

Offspring formed due to sexual reproduction have better chances of survival. Why? Is this statement always true?

Why is the offspring formed by asexual reproduction referred to as clone?

Which is a better mode of reproduction sexual or asexual? Why?

Why is reproduction essential for organisms?