The document discusses the various reproductive strategies of representative animals, focusing on sexual and asexual reproduction. It outlines the definitions, advantages, and disadvantages of both methods, emphasizing the importance of reproduction for species continuity. Activities and assessments are included to help students explore these concepts through presentations and class discussions.

1. EARTH AND LIFE
SCIENCE
Prepared by: MRS. ANGELI Y. DULLO, RN. LPT

2. Describe the different ways in
which representative animals
reproduce.

3. OBJECTIVES
1. Define what is “Reproduction.”
2. Identify the advantages and
disadvantages of the different methods
of reproduction.
3. Appreciate the importance of
reproduction.

4. REVIEWING
UNIFYING THEMES OF LIFE
1. Biological systems
2. The cellular basis of life
3. Structure and Function
4. Reproduction and Inheritance
5. Environmental Interactions

5. REVIEWING
UNIFYING THEMES OF LIFE
6. Energy and Life
7. Regulation
8. Evolution and Diversity
9. Scientific Inquiry
10. Science Technology and
Society

6. 1. Why do organisms reproduce?
2. What would happen to a species if
every individual from that species
suddenly lost the ability to
reproduce?

7. ACTIVITY
TIME

8. Instructions
1) A gallery of pictures and descriptions of
animals and their reproductive strategies.
2) In groups, students rotate around the
gallery, discussing each animal’s
reproduction method.
3) After the walk, groups present one
unique reproductive strategy to the class.

9. ANALYSIS
1) What are the different reproductive
strategies observed in the gallery?
2) How do these strategies help the species
survive?
3) Can you compare two different reproductive
methods and their advantages?

10. Reproduction is the biological process by
which organisms create offspring,
ensuring the continuation of their
species. It's a fundamental aspect of life,
and different species have developed a
variety of strategies to reproduce
successfully.

11. Methods Of Reproduction
A. Sexual Reproduction
It is the mode of reproduction in which
gamete cells from two organisms, one
male and one female, combine to form a
singular zygote. This zygote shares half of
its genetic information with the father and the
other half with the mother.

13. Sexual reproduction allows some of
the genetic information from each
parent to mix, producing offspring that
resemble their parents but are not
identical to them. In this way, sexual
reproduction leads to variety in the
offspring. Animals and plants can
reproduce using sexual reproduction.

14. In sexual reproduction, new organisms
are produced from the fusion of a male
sex cell with a female sex cell. This fusion
of gametes is called fertilization.
Sex cells are also known as gametes.
Male gametes are made by male
reproductive structures. Female gametes
are made by female reproductive
structures.

15. MALE STRUCTURE
Male gametes are called sperm cells. They
are continuously produced in the testes

16. FEMALE
STRUCTURE
Female gametes are called egg cells OR ova/ovum
and are produced in the ovaries of the female
mammal.

18. In human beings, each gamete contains 23
chromosomes, half the number found in the
other cells of the body. When the male and
female gametes fuse, they become a zygote
containing the full 46 chromosomes, half of
which came from the father and half from the
mother.

19. Sexual Reproduction in Plants
Plants that reproduce sexually have sex parts
which we know as flowers. The process of
reproduction involves the fusion of male
gametes, namely, pollen with the female
gamete, also known as ovules. This fusion
results in the formation of a zygote and an
endosperm nucleus, which grow into seeds and
fruits respectively.

20. Advantages:
Genetic Diversity: Creates offspring with
unique combinations of traits, enhancing
adaptability to changing environments.
Disease Resistance: Genetic diversity can
make populations less susceptible to
diseases.
Evolutionary Advantage: Provides the raw
material for natural selection, driving
evolution.

21. Disadvantages:
Time-Consuming: Requires finding a mate
and the complex process of gamete
production and fertilization.
Resource-Intensive: Can require significant
energy and resources for courtship, mating,
and offspring care.
Reduced Population Growth: Compared to
asexual reproduction, sexual reproduction
can lead to slower population growth.

22. B. Asexual Reproduction
It is the mode of reproduction which
involves only one organism. The offspring
that is produced is genetically identical to
the mother and almost always has the
same number of chromosomes. Hence,
they are called clones. Moreover, they are
exact copies of their parent cell.

24. Entities prefer to reproduce asexually by
different means. Few asexual methods
are budding (e.g. Hydra), binary fission
(e.g. Amoeba, bacteria), spore formation
(e.g. ferns), fragmentation (e.g.
Planaria), and vegetative propagation
(e.g. Onion).

25. Asexual Reproduction in Plants
Some plants have the ability to
reproduce asexually, that is, without
the help of flowers or pollens. There
are different modes of asexual
reproduction in plants, both natural
and human-induced.

26. In the natural mode of asexual
reproduction, a plant can give rise to an
offspring with the help of roots. Certain
plants also use budding and cutting to
reproduce asexually.
Human-induced asexual reproduction in
plants includes grafting, layering, cutting
and micropropagation.

27. Asexual Reproduction in Animals
Some simple animals, many of which are
single-celled, reproduce asexually.
The different modes of asexual reproduction
in animals include gemmules (sponges),
fragmentation (planarians), regeneration
(echinoderms) and parthenogenesis (ants,
wasps)

28. Advantages:
Rapid Population Growth: Can produce large
numbers of offspring quickly, especially in
favorable conditions.
Energy Efficient: Requires less energy and
resources compared to sexual reproduction.
Preservation of Traits: Offspring are genetically
identical to the parent, preserving beneficial traits.

29. Disadvantages:
Lack of Genetic Diversity: This can make
populations more vulnerable to diseases or
environmental changes.
Reduced Adaptability: Limited genetic variation
can hinder a species' ability to adapt to new
conditions.
Accumulation of Harmful Mutations: Over time,
harmful mutations can accumulate in a population.

30. APPLICATION
Problem-Based
Create a presentation comparing two
animals with different reproductive
strategies, discussing how these strategies
affect their survival and adaptation.

31. Rubric
- Participation in discussion - 5 pts.
- Clarity of presentation - 5 pts.
- Engagement with peers - 5 pts.

32. Assessment
1. What defines sexual reproduction,
and how does it differ from asexual
reproduction?
2. How do environmental factors
influence reproductive
strategies in animals?

33. A picture is worth a thousand words