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Questions
Give the importance of variation in survival of species.
Why is variation important for a species?
Solution
Importance of variation in survival of species:
- Variations result in variety and diversity.
- Due to adaptive variations, organisms are able to survive in changed environmental conditions.
- It prevents complete extinction of any species.
- Evolution continues through these variations and adaptations.
RELATED QUESTIONS
Write one difference between asexual and sexual mode of reproduction.
Higher organisms have resorted to sexual reproduction in spite of its complexity. Why?
In which female reproductive organ does the embryo get embedded?
State the basic requirement for sexual reproduction?
Advantages of sexual reproduction.
Which species is likely to have better chances of survival - the one reproducing asexually or the one reproducing sexually? Justify your answer.
What is the other name of sex cells?
Fill in the following blank with suitable word :
The cells involved in sexual reproduction are called .............
Fill in the following blank with suitable word :
A multicellular animal starts its life from a ........... through sexual reproduction.
Describe the various steps involved in the sexual reproduction in animals. Draw labelled diagrams to show the fertilisation of an ovum (or egg) by a sperm to form a zygote
Name two plants which reproduce by sexual reproduction method and two plants which reproduce by asexual reproduction methods.
Distinguish between a gamete and a zygote.
Characters that are transmitted from parents to offspring during sexual reproduction show :
(a) only similarities with parents
(b) only variations with parents
(c) both similarities and variations with parents
(d) neither similarities nor variations with parents
The correct sequence of organs in the male reproductive system for the transport of sperms is:
(a) testis → vas deferens → urethra
(b) testis → ureter → urethra
(c) testis → urethra → ureter
(d) testis → vas deferens → ureter
Differentiate between the following:
Sperm and Ovum
Define the term Adolescence.
Mention the common method of reproduction in Hydra.
Mention the common method of reproduction in Flatworm.
Adolesecence is considered a critical stage in the life of boys and girls. Explain this statement.
Meiosis is an essential event in the sexual life cycle of any organism. Give two reasons.
What is sexual reproduction? List its four significances.
Explain why variations are observed in the offsprings of sexually reproducing organisms?
Answer the following question.
Explain the process of fertilization in humans.
Answer the following question.
Explain the following parts of male reproductive system along with labelled diagram showing these parts- Testis, vasa deferentia, epididymis, seminal vesicle, prostate gland and penis.
What is atresia with respect to ovary in human females?
Describe the histology of testis with help of labelled diagram.
What are the different stages of sexual reproduction?
Choose the correct statement from the following
Name an organism where cell division is itself a mode of reproduction.
Differentiate between the following:
Regeneration in lizard and Planaria
How is juvenile phase different from reproductive phase?
Name the phenomenon where the female gamete directly develops into a new organism with an avian example.
Which of the following is the male accessory gland?
Match column -1 with column - II and select the correct option.
| Column - I | Column - II | ||
| 1. | Seminal vesicles | a. | Membranous urethra |
| 2. | Scrotum | b. | Thermoregulatory |
| 3. | Tunica vaginalis | c. | Fibro muscular pouches |
| 4. | Cowper's gland | d. | Peritoneal covering |
Choose the correct statements from the options below:
A few statements with regard to sexual reproduction are given below:
- Sexual reproduction does not always require two individuals
- Sexual reproduction generally involves gametic fusion
- Meiosis never occurs during sexual reproduction
- External fertilisation is a rule during sexual reproduction
______ fertilisation takes place in frogs and fish.
The zygote divides repeatedly into a group of cells, which develops into different tissues and organs constituting a full body. This structure is known as ______.
Animals in which an embryo develops outside the body are called ______ animals.
The eggshell protects the ______ from the outer environment.
Name the two ways by which fertilisation in animals takes place.
Justify the statement ‘Vegetative reproduction is also a type of asexual reproduction’.
Enumerate the differences between asexual and sexual reproduction. Describe the types of asexual reproduction exhibited by unicellular organisms.
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.
Both these plants - rose and tomato - both selected by human beings for different characteristics, the rose for its flower and tomato for its fruit. Roses, being vegetatively propagated do not need to produce seeds.
Which is a better mode of reproduction, sexual or asexual? Why?
