Lesson PLANT AND ANIMAL

1 REPRODUCTION

OBJECTIVES:

At the end of the lesson, the learners shall be able to:

K: differentiate the two modes of plant and animal
reproduction (asexual and sexual)
S: list down the parts of the reproductive organs of plants and
animals
A: recognize the advantages and disadvantages of asexual
and sexual reproduction in plants and animals

LEARNING COMPETENCY

Compare and contrast the following processes in plants and

animals: reproduction, development, nutrition, gas exchange,
transport/circulation, regulation of body fluids, chemical and
nervous control, immune systems, and sensory and motor
mechanisms (STEM_BIO11/12-IVa-h-1)

I. WHAT HAPPENED

PRE-ACTIVITIES/PRE-TEST

IDENTIFICATION: Complete the sentences by supplying the correct word(s) from

the word pool. Write the answers in your notebook.

A. PLANT REPRODUCTION

Pollination Genetic; Staminate, Scion; stock;

identical pistillate cambium
Simple Propagules Petals Pollen; water
fruit new staminate Ovulate; pollen
combinations tube;
archegonium;
embryo
 1. The main advantage of asexual reproduction, in addition to its speed, is that it
permits the propagation of advantageous
makeups since the offspring are genetically with the
parent.
2. Sexual reproduction, on the other hand, permits
of traits to arise from the contributions of multiple different
ancestors.
3. Certain plants produce body parts specialized for breakaway and dispersal
that are known as .
4. In grafting, the plant that is to be asexually propagated is known as the
; this is attached to the ,
which may be little more than a root. It is important that the two have their
layers in contact with each other.
5. The production of by the seed plants largely
circumvents the requirement found in ferns, mosses, and the like for
as a requirement for fertilization.

B. ANIMAL REPRODUCTION

Fragmentation Hermaphroditic sterile

Gamete; zygote Sexual and asexual Develops into a new
generations individual

1. The type of reproduction in which an animal divides into several pieces and
then each piece develops into an entire new animal is called
.
2. In metagenesis there is an alternation of
.
3. Parthenogenesis is a type of reproduction in which an unfertilized egg
.
4. An individual that can produce both eggs and sperm is described as
.
5. A sex cell (either egg or sperm) is properly called a
; a fertilized egg is a
.

II. WHAT I NEED TO KNOW

DISCUSSION
A. Plant Reproduction

The propagation of flowering plants by sexual and asexual reproduction

forms the basis of agriculture. We will explore the reproductive biology of flowering
plants in much greater detail because they are the most important group of plants
in most terrestrial ecosystems and in agriculture.

The life cycles of plants are characterized by an alternation of generations,

in which the haploid (n) and diploid (2n) generations take turns producing each
other. The sporophyte (diploid plant) produces haploid spores by meiosis, which
then divide by mitosis and giving rise to the gametophytes (the small male and
female haploid plants that produce gametes: sperm and eggs). Fertilization results
in diploid zygotes, which divide by mitosis and form new sporophytes.

FLOWER STRUCTURE

Flowers, the reproductive shoots of the angiosperm sporophyte, are

typically composed of four whorls of highly modified leaves called floral organs,
which are separated by very short internodes. They are called determinate shoots,
meaning that they stop growing after the flower and fruit are formed.
The floral organs – sepals, petals, stamens, and carpels (pistils) – are
attached to a part of the stem called the receptacle. Stamens and carpels are
reproductive organs, whereas sepals and petals are sterile. Sepals, which enclose
and protect the floral bud before it opens, are usually green and more leaflike in
appearance than the other floral organs. In most cases, petals are more brightly
colored than sepals and attract the flower to insects and other pollinators.
A stamen consists of a stalk called the filament and a terminal structure
called the anther; within the anther are chambers called pollen sacs, in which
pollen is produced.
A carpel has an ovary at its base and a long, slender neck called the style.
At the top of the style is the sticky structure called the stigma that serves as a
landing platform for pollen. Within the ovary are one or more ovules, with the
number depending on the species. The term pistil is sometimes used to refer to a
single carpel or to group of fused carpels.

https://www.sciencevision.in/pollination/
Types of flowers based on the presence of the whorls:

A. Complete - is a plant biology term that is used to describe a flower that

is built with four parts which include the sepals, petals, pistils, and stamens.

B. Incomplete - If any of the sepals, petals, pistils, and stamens, which are
integral in forming a flower, is missing, a flower is called an incomplete
flower.

Types of flowers based on the presence of the reproductive whorls:

A. Perfect/Bisexual – is one in which both male and female reproductive

structures are present. Both androecium (whorl of stamens) and gynoecium
(whorl of carpels or pistil) are located on the same flower.
Example: Roses

B. Imperfect/Unisexual - flower that does not have both male and female
structures.
b.1. staminate flower (male)
b.2. carpellate/pistillate flower (female)
Examples: squashes, cucumbers, corn, and grasses

GAMETOPHYTE DEVELOPMENT AND POLLINATION

Anthers and ovules bear sporangia, structures where spores are produced
by meiosis and gametophytes develop. Pollen grains, each consisting of a mature
male gametophyte surrounded by a spore wall, are formed within pollen sacs
(microsporangia) of anthers. An egg-producing female gametophyte, or embryo
sac, forms within each ovule.
In angiosperms, pollination is the transfer of pollen from an anther to a
stigma. If pollination is successful, a pollen grain produces a structure called a
pollen tube, which grows and digests its way down into the ovary via the style and
discharges sperm in the vicinity of the embryo sac, resulting in fertilization of the
egg. The zygote gives rise to an embryo, and as the embryo grows, the ovule that
contains it develops into a seed. The entire ovary, meanwhile, develops into a fruit
containing one or more seeds, depending on the species. Fruits, which disperse by
dropping to the ground or being carried by wind or animals, help spread seedssome
distance from their source plants. When light, soil, and temperature conditions
are suitable, seeds germinate and the embryo carried in the seed grows and
develops into a seedling (Campbell & Reece, 2005).
The development of angiosperm gametophytes (pollen grains and embryo sacs)

http://cikgurozaini.blogspot.com/2010/07/development-of-angiosperm-gametophytes.html

We have tackled the process of gametophyte development and

pollination. At this point, let us get to know fertilization and its products: the seeds
and the fruits.

DOUBLE FERTILIZATION

After landing on a receptive stigma, a pollen grain absorbs moisture and

germinates; that is, it produces a pollen tube that extends down between the cells
of the style toward the ovary.
Growth of the pollen tube and double fertilization.

http://cikgurozaini.blogspot.com/2013/08/double-fertilisation-in-angiosperm.html

From Ovule to Seed

After double fertilization, each ovule develops into a seed, and the ovary
develops into a fruit enclosing the seed(s). As the embryo develops from the
zygote, the seed stockpiles proteins, oils, and starch to varying extents, depending
on the species. This is why seeds are such major sugar sinks. Initially, these nutrients
are stored in the endosperm, but later in seed development in many species, the
storage function of the endosperm is more or less taken over by the swelling
cotyledons of the embryo (Campbell & Reece).

https://slideplayer.com/slide/7711878/

From Ovary to Fruit

While the seeds are developing from ovules, the ovary of the flower is
developing into a fruit, which protects the enclosed seeds and, when mature, aids
in their dispersal by wind or animals. Fertilization triggers hormonal changes that
cause the ovary to begin its transformation into a fruit. If the flower has not been
pollinated, fruit usually does not develop, and the entire flower withers and falls
away.

During fruit development, the ovary wall becomes the pericarp, the
thickened wall of the fruit. As the ovary grows, the other parts of the flower wither
and are shed (Campbell & Reece).
 Developmental origin of fruits.

https://biology-forums.com/index.php?action=gallery;sa=view;id=32660

B. ANIMAL REPRODUCTION

Just like the plants, animals reproduce with two principal modes: asexual
(without sex) and sexual (fusion of gametes) reproduction.
Asexual reproduction is the creation of new individuals whose genes all
come from one parent without the fusion of egg and sperm.
Sexual reproduction is the creation of offspring by the fusion of haploid
gametes to form a zygote (fertilized egg), which is diploid.
The female gamete, the unfertilized egg (also called an ovum), is a
relatively large cell and not motile.
The male gamete, the sperm, is generally a much smaller, motile cell.
Sexual reproduction increases genetic variability (one of its advantages
over asexual reproduction) among offspring by generating unique combinations of
genes inherited from two parents. Thus, by producing offspring having a varietyof
phenotypes, sexual reproduction may enhance the reproductive success of
parents when environmntal factors (including pathogens) change relatively
rapidly.
Asexual reproduction has several potential advantages. For instance, it
enables animals living in isolation to produce offspring without locating mates. It
can also create numerous offspring in a short amount of time, which is ideal for
colonizing a habitat rapidly. Theoretically, asexua reproduction is most
advantageous in stable, favorable environments because it perpetuates
successful genotypes precisely.

Mechanisms of Asexual Reproduction

In asexual reproduction, a singe parent splits, buds, or fragments to give

rise to two or more offspring that have hereditary traits identical with those of the
parent.

TYPES OF CHARACTERISTICS EXAMPLES

ASEXUAL
REPRODUCTION
Fission the separation of a parent into two or more Sea anemone
individuals of approximately equal size.
Budding in which new individuals arise from Cnidarians
outgrowths of existing ones; the offspring and tunicates
may either
Fragmentation the breaking of the body into several Flatworms
pieces, some or all of which develop into
complete adults.
Regeneration the regrowth of lost body parts; usually Sea stars
accompanied with fragmentation.

Mechanisms of Sexual Reproduction

Sexual reproduction involves two parents. Each contributes a specialized

gamete (an egg or sperm); these fuse to form the fertilized egg, or zygote.
Fertilization, the fusion of sperm and egg, may take place inside the body
(internal fertilization) or outside the body (external fertilization).

TYPES OF FERTILIZATION
Internal Fertilization External Fertilization
The male generally delivers sperm Mating patners usually release eggs and
cells directly into the body of the sperms into the water simultaneously.
female. Her moist tissues provide the
watery medium required for
movement of sperm.
Examples: Many fish, amphibians, and
Examples: Most terrestrial animals, other sexual aquatic animals use
few fish and some other aquatic external fertilization (the exceptions are
animals aquatic mammals, sharks, and some
other special types of fish)
REPRODUCTIVE SYSTEMS

The details of the reproductive process vary tremendously from one

organism to another, and so some generalizations were made about animal
reproductive systems in order to understand its variations.

REPRODUCTIVE SYSTEMS
MALE FEMALE
1. Male gonad (testis) 1. Female gonad (ovary)
- in which sperm are produced - in which eggs are produced
2. Sperm duct 2. Oviduct
- used for the transport of sperm - a tube for the transport of egg
to the exterior of the body 3. Vagina
3. Penis - the terminal portion of the oviduct
- the terminal part of the sperm responsible for the receiving of male
duct which opens onto or into a copulatory organ
copulatory organ

Some Reproductive Variations

Some animals show unique and tremendous diversity in their methods of

reproduction. Even members of the same class may differ markedly in their
reproductive process.

A. Metagenesis – also known as ‘transformation development’, refers to

an alternation of asexual and sexual generations.

Example: hydrozoan Obelia, a polyp generation gives rise by budding to a

generation of medusas. The motile medusas produce gametes and
reproduce sexually, giving rise to new generation of polyps. Thus, there is
alternation of generations – polyp, medusa, polyp, medusa, and so on.
Both generations consist of diploid organisms.

https://www.toppr.com/guides/biology/animals/obelia-structure-diagram-life-cycle/
B. Parthenogenesis – also known as ‘virgin development’, is a form of
reproduction in which an unfertilized egg develops into an adult animal.
This occurs for several generations, after which males develop, produce
sperm, and mate with females to fertilize their eggs. In some species,
parthenogenesis is advantageous in maintaining social order; in others, it
appears to be an adaptation for survival in times of stressor when there is a
serious decrease in population.

Example: Honeybees. The queen honeybee is inseminated by a male

during the “nuptial flight”. The sperm she receives are stored in a little pouch
connected with her genital tract but closed off by a muscular valve. As the
queen lays eggs, she can either open this valve, permitting the sperm to
escape and fertilize the eggs, or keep the valve closed, so that the eggs
develop without fertilization. Generally, fertilization occurs in the fall, and
the fertilized eggs are quiescent during the winter. The fertilized eggs
become females (queens and workers); the unfertilized eggs become
males (drones).

https://www.pinterest.ph/pin/515591857323446143/

C. Hermaphroditism – means that a single organism produces both eggs

and sperm. Although this form of reproduction is still classified as sexual,
(since both eggs and sperms are involved), it is an exception to the
important generalization that sexual reproduction involves two different
individuals.

Example: Earthworm. Most hermaphrodites do not reproduce by self-

fertilization. Rather, as in earthworms, two animals copulate, and each
 inseminates the other.

http://www.soilanimals.com/look/soil-
foodweb?tmpl=%2Fsystem%2Fapp%2Ftemplates%2Fprint%2F&showPrintDialog=1

Human Reproduction

FEMALE REPRODUCTIVE ANATOMY

https://www.webmd.com/sex-relationships/guide/your-guide-female-reproductive-system
https://microbenotes.com/female-reproductive-system/

Ovaries - Produce both the egg cell and the sex hormones. Enclosed in
a tough protective capsule and contains many follicles. Egg cell is expelled
from the follicle in the process of ovulation.

Oviducts and Uterus – Egg cell is released into the abdominal activity near
the opening of the oviduct, or fallopian tube. The uterus is a thick, muscular
organ that can expand during pregnancy to aaccommodate a 4-kg fetus.
The inner lining of the uterus, the endometrium, is richly supplied with blood
vessels. The neck of the uterus is the cervix, which opens into the vagina.

Vagina and Vulva – a thin-walled chamber that is the repository for sperm
during copulation and that serves as the birth canal through which a baby is
born. Vulva is a collective term for the external female genitalia. Vestibule,
labia minora, labia majora, clitoris, and Bartholin’s glands are all located in
this area having their special functions.
 Mammary glands – present in both sexes but normally function only in
women. They are not part of the reproductive system but are important to
mammalian reproduction. Within the glands, small sacs of epithelial tissue
secrete milk which drains into a series of ducts opening at the nipple.

MALE REPRODUCTIVE ANATOMY

https://www.earthslab.com/physiology/male-reproductive-system-locations-functions-male-reproductive-organs/
https://www.pixtastock.com/illustration/45939563

Testes (singular, testis) – consist of many highly coiled tubes (seminiferous tubules
– where sperm form) surrounded by several layers of connective tissue. The Leydig
cells that are scattered between the seminiferous tubules produce testosterone
and other androgens. The production of normal `sperm cannot occur at the
normal body temperatures of most mammals, and the testes of humans and
many other mammals are held outside the abdominal cavity in the scrotum.

Ducts – from seminiferous tubules, the sperm pass into the epididymis. During
ejaculation, the sperm are propelled from the epididymis through the muscular
vas deferens. These two ducts (one from each epididymis) run from the scrotum
around and behind the urinary bladder, where each joins a duct from the seminal
vesicl, forming a short ejaculatory duct. The ejaculatory ducts open into the
urethra, the tube that drains both the excretory system and reproductive system
of male. The urethra runs through the penis and opens to the outside at the tip of
the penis.

Glands – three sets of accessory glands – the seminal vesicles, prostate gland, and
bulbourethral glands – add secretions to the semen, the fluid that is ejaculated.

Semen in the Female Reproductive Tract – males usually ejaculates 2-5 ml of

semen, and each milliliter may contain 50-130 million of sperm. Prostaglandins in
the semen cause thinning of the mucus at the opening of the uterus and stimulate
contractions of the uterine muscles, which help semen move up to the uterus.

Penis – is composed of three cylinders of spongy erectile tissue derived from

modified veins and capillaries. During sexual arousal, the erectile tissue fills with
blood from the arteries. As this tissue fills, the increasing pressure seals off the veins
that drain the penis, causing it to engorge with blood. The resulting erection is
essential to insertion of the penis into the vagina.

HUMAN SEXUAL RESPONSE

2 TYPES OF PHYSIOLOGICAL REACTIONS

1. VASOCONGESTION – the filling of a tissue with blood caused by increased

blood flow through the arteries of that tissue.

2. MYOTONIA – increased muscle tension of both skeletal and smooth

muscles.

4 PHASES OF HUMAN SEXUAL RESPONSE

1. EXCITEMENT PHASE – preparation of penis and vagina for coitus (sexual

intercourse). During this phase, vasocongestion is particularly evident in erection
of the penis and clitoris; enlargement of the testes, labia, and breasts; and
vaginal lubrication. Myotonia may occur, resulting in nipple erection or tension
of the arms and legs.

2. PLATEAU PHASE – responses in excitement phase continue. In females,

the outer third of the vagina becomes vasocongested, while the inner two-thirds
slightly expands. This change, coupled with the elevation of the uterus, forms a
depression that receives sperm at the back of the vagina. Breathing increases
and heart rate rises, sometimes to 150 beats per minute – not in response to the
physical effort of sexual activity, but as an involuntary response to stimulation of
the autonomic nervous system.

3. ORGASM PHASE – is characterized by rhythmic, involuntary contractions

of the reproductive structures in both sexes.
Male orgasm has two stages. Emission is the contraction of the glands and
ducts of the reproductive tract, which forces semen into the urethra. Expulsion or
ejaculation, occurs when the urethra contracts and the semen is expelled.
During female orgasm, the uterus and outer vagina contract, but the inner
two-thirds of the vagina do not. Orgasm is the shortest response of the sexual
response cycle, usually lasting only a few seconds.

4. RESOLUTION PHASE – completes the cycle and reverses the responses of

the earlier stages.
Contraception and its types
TYPES EXAMPLE
Ovulation-suppressing method Oral contraceptives (pills)
Barrier methods Condom, Diaphragm, Cervical cap
Chemical Spermicidal jelly and foam
Surgical methods Vasectomy and Tubal ligation
Implantation-suppressing methods IUD and Morning-after pill
Others Abstinence
Note: Abstinence is the only form of contraception that is guaranteed 100% effective.

Activity 2: Complete the table by listing the advantages and disadvantages of

asexual and sexual reproduction in plants and animals.

Type Advantage Disadvantage

Asexual reproduction
Sexual reproduction

III. WHAT I HAVE LEARNED

POST-TEST

I. Matching type. Select the most appropriate answer from column B for each
description in column A. Write the letter of the correct answer only in your activity
notebook.

Column A Column B
1. Regeneration A. Asexual reproduction
2. Internal fertilization B. Sexual reproduction
3. Budding
4. External fertilization
5. Fission

III. Enumeration

6-9. List down at least 4 organs of the male reproductive system (human)
10-14. List down at least 5 female internal reproductive organs (human)
15-20 List down the 6 types of contraception
21-22. Enumerate the male reproductive organs of plants
23-25. Enumerate the female reproductive organs of plant