Genbio 2 chapter 6 (perpetuation of life) harold morales

Along your way you will also
meet some interesting
friends that will help you in
your quest. So be sure to
befriend them!
Hi, I’m Finn. Welcome to my world full of
adventure. Today we will learn new
exciting lessons about BIOLOGY. I will be
your guide as you travel different places in
my world.
PHILIPPINE NORMAL UNIVERSITY- NORTH LUZON

Guide Card Activit
y
Assessmen
t
Reference
s
Choose
an
action!

GUIDE CARD
• Differentiate what is asexual reproduction in
plants and animals
• Learn how sexual reproduction happens in
plants and animals.
• Explain the process of fertilization on plants
and animals.
• Determine how DNA manipulate or
influences the organism from parents to
offspring
Hi I’m BMO. While
you are here, you
are expected to
meet the following
objectives:
PERPETUATION OF LIFE

Hi I’m Jake and i’m a
magical dog, today you
will be learning about
“Flowering plants”
IN THE CANDY KINGDOM
Let;s talk about
Asexual
Reproduction
Asexual reproduction is a type of reproduction that
produces identical offspring's from a single parent
plant therefore eliminates genetic recombination. One
strategy of plants reproducing asexually is through its
vegetative parts such as stems, roots or leaves.
Asexual reproduction can occur naturally or artificially
with the aid of humans.
Plants’ diverse reproductive
strategies allow them to become
widely distributed in geographic
regions of the world
ASEXUAL IN FLOWERING PLANTS
6.1
LESSO
N 6.1
Asexual
Reproduction
In Flowering
Plants

• The type of reproduction in plants from its vegetative parts or specialized reproductive
structures is called vegetative reproduction.
• Stems, leaves and roots are vegetative organs that are modified to carry out a reproductive
function.
• The structure in plants that reproduce vegetatively come mostly from modified stems, such
as runners, tubers, corms and rhizomes.
NATURAL VEGETATIVE REPRODUCTION
6.1

6.1
Stolons or runners, which are long, horizontal stems that run
aboveground or along the surface of the soil. Example – Strawberries.
They produce a new shoot system above its node and a new root system
below its node.
Rhizomes are underground stems that allow
some plants to form a network and produce
their kind. Ginger and turmeric plants reproduce
via these horizontal underground stems.

6.1
Tubers are specialized underground stems for storage and reproduction
(example Potato). Each eye is a bud where a new potato plant will form.
New shoots arise from axillary bud on swollen, short, fleshy underground
stem.
Bulbs and Corms are short, vertical
underground stems. Onions arise from axillary
bud on very short stem with thick fleshy
leaves (only in monocots). And Corms like
Gladiolus arise from very short, thickened,
underground stem with thin, scaly leaves.

ARTIFICIAL PROPAGATION METHODS
TAKE NOTE:
The discovery of the hormone AUXIN
and its ability to cause the roots to
develop has led to the farmer’s ability
to propagate from stem cuttings.
• Each plant generated is identical and genetically the same as the parent
tree and is called a CLONE.
• Some plants can be propagated by stem cuttings (sugarcane, apple,
pineapple). The cuttings are then stimulated to the root through the
treatment of plant hormones such as auxin.
6.1 ASEXUAL IN FLOWERING PLANTS

GRAFTING
• Which attaches a piece of stem from one plant to a root or root-bearing stem of
another plant.
• This results to a combination of root-bearing host known as the stock, and the
grafted part known as the scion.
• Over time, the vascular system of the scion will merge with that of the stock,
forming a continuous vascular system producing xylem and phloem to transport
water and other nutrients through the plant’s body.

TISSUE
CULTURE
• It is the growth of plant tissues in an artificial liquid or solid culture media.
• The cloning of plants through this process is because of its ability to grow single
cells (Totipotent), or the ability of a plant cell to become a new plant.
• 3 methods of tissue culture: Somatic embryogenesis, meristematic tissue
culture, and anther tissue culture.
• Examples: orchids, potatoes and many house plants.

THINK!
What is the characteristic of the offspring of the plant produce in
an asexual reproduction?
ANSWER:
Asexual reproduction produces identical offspring from a single
parent plant.
THINK THE ANSWER FOR
TEN SECONDS

Before you can enter the
house you need to answer
another question.
CONCEPT CHECK
How do flowering plants reproduce asexually?

LESSON
5.2
Sexual
Reproduction
in Plants
GOOD JOB! You have learned
asexual reproduction with
Jake. Now you will be
learning about Sexual
Reproduction.
TAKE NOTE:
Angiosperms, or commonly known as the
flowering plant, are widely distributed in the
world. Flowers are their sexual organs.
Sexual reproduction in flowering plants involves the fusion of sex cells
from parent plants. Plants reproduce sexual characteristics by
alternation of generations. Through this reproductive pattern, plants’
diploid sporophyte generations that produces a haploid gametophyte
generation that fuses to generate a new diploid sporophyte.
At Marceline’s
House
6.2 SEXUAL REPRODUCTION PLANTS

• The male
gametophyte is the
pollen that later on
develop from
microspores.
• The female
gametophyte is the
embryo sac that
develops from a
megaspore.
• Seeds protect the
future embryo from
harm and only grow
when favorable
conditions exist.

• Sepals – leaf-like
green structures
protecting the bud as
the flower develops.
(Calyx-collective term)
• Petals – what makes
the flower attractive
because of its colors,
shapes and sizes
(collective term-
Corolla)
Parts of a Flower

• Stamen – male
reproductive part
• Anther – makes
tiny grains called
pollens, which
contains male sex
cells.
• Filament – holds
up the anther.
MALE ORGAN
• Carpel – female
reproductive part
• Stigma – top part of
the carpel with sticky
surface to trap pollen
• Style – joins the
stigma and the ovary
• Ovary – containes
the female sex cells
called ovules.
FEMALE ORGAN

Stages of Sexual
Reproduction in Plants
POLLEN AND EGG
FORMATION
• Pollen sacs contains microspore mother
cells will form four haploid microspores
through meiosis.
• Meiotic divisions will form pollen grains
from a generative cell and a tube cell
nucleus.
• Tube cell nucleus will form pollen tube
• Generative cell divide to form two sperm
cells.

Stages of Sexual Reproduction
in Plants
POLLEN AND EGG
FORMATION
• Egg cells are formed in the ovule.
• A megaspore mother cell will undergo
meiotic division to produce four haploid
megaspores.
• Mostly in plants, only one of the four
megaspores will develop out of repeated
mitotic divisions to produce eight haploid
nuclei which will be encased by an embry
sac.

The next stage in
the sexual
reproduction of
flowering plants is
• In angiosperms, pollination is the transfer of pollen
from an anther to a stigma
• Pollination can be by wind, water, or animals
• Self-pollination when pollen is carried from the
stamen to the stigma of the same plant.
• Cross-pollination when pollen is carried to the sigma
of another plant.
POLLINATION
Some Pollinators

The next stage in
the sexual
reproduction of
flowering plants is
• Coevolution is the evolution of interacting
species in response to changes in each other
• Many flowering plants have coevolved with
specific pollinators
• The shapes and sizes of flowers often
correspond to the pollen transporting parts of
their animal pollinators
– For example, Darwin correctly
predicted a moth with a 28 cm long
tongue based on the morphology of a
particular flower
POLLINATION

FERTILIZATION
• After landing on a receptive stigma, a pollen grain produces a pollen tube that extends
between the cells of the style toward the ovary
• Double fertilization results from the discharge of two sperm from the pollen tube into the
embryo sac
• One sperm fertilizes the egg, and the other combines with the polar nuclei, giving rise to
the triploid food-storing endosperm (3n)

So what happens
next?
REMEMBER!
A fruit have two purposes: to protect the seed from
damage against animals and infectious diseases, and to
aid in seed dispersal
Now lets talk about seed
Dispersal!
After fertilization, the zygote’s cells will undergo further mitotic
division. In turn, the primary endosperm nucleus will develop into
the endosperm, which will provide nourishment for the embryo. The
ovary swells up and ripens to form a FRUIT, which may contain one
or many seeds.

What about SEED
DISPERSAL?
The different fruits that
abound Earth reflect the
variety of strategies
plants use to disperse
their population. Since
they are not mobile,
plants employ several
mechanisms to disperse
themselves separate the
parents from the
offspring. Many fruits
disperse their seed over
distance to increase their
probability of survival.

A SEED is a reproductive structure
where a plant embryo and a food
source are contained within a seed
coat (testa). A seed is surrounded by
a seed coat that protects the
delicate tissues inside.
SELF CHECK
Give three differences
between a monocot and a
dicot seed

Fruit dispersal
mechanisms include
Wind, Water and Animals

NOW WHAT IS
GERMINATION?
• Germination depends on imbibition, the uptake of water
due to low water potential of the dry seed
• The radicle (embryonic root) emerges first
• Next, the shoot tip breaks through the soil surface
• In many eudicots, a hook forms in
the hypocotyl, and growth pushes
the hook above ground
• Light causes the hook to
straighten and pull the cotyledons
and shoot tip up

NOW WHAT IS
GERMINATION?
In maize and other grasses, which
are monocots, the coleoptile
pushes up through the soil.
SELF CHECK
What are the different ways
on how plants disperse their
seeds?

Where are we?
We are at the dungeon.
We’re going to meet my
brother Marshall Lee
here.
Why here? It's so
creepy!
YOHH!

LESSON
6.3
NEXT CHAPTER OF
ADVENTURE
Both asexual and sexual
reproduction occur in the animal
kingdom
Sexual reproduction is the creation of an offspring by fusion of a male
gamete (sperm) and female gamete (egg) to form a zygote
Asexual reproduction is creation of offspring without the fusion of
egg and sperm
ANIMAL REPRODUCTION
6.3

How do animals
reproduce asexually?
Asexual Reproduction in Animals
Many invertebrates reproduce
asexually by fission, separation of a
parent into two or more individuals of
about the same size. Advantage of this
is that organisms can produce many
offspring in a short period of time.
Major disadvantage is it lacks variation
among individuals.
Asexual reproduction of a sea anemone
(Anthopleura elegantissima).
ANIMAL REPRODUCTION
6.3

How do animals
reproduce asexually?
Through mitosis, unicellular
organisms such as Amoeba or
Paramecium can produce an
exact copy of the parent in an
asexual process called FISSION
ANIMAL REPRODUCTION
6.3

In budding, new individuals arise from outgrowths of existing ones
Fragmentation is breaking of the body into pieces, some or all of which develop into
adults
Fragmentation must be accompanied by regeneration, regrowth of lost body parts
Parthenogenesis is the development of a new individual from an unfertilized egg
ANIMAL REPRODUCTION
6.3

DID YOU KNOW?
Parthogenisis in honeybees, the
queen bee only mates once
and stores sperm, which she
will use to selectively fertilize
eggs. If the egg does not
receive sperm, it will develop
parthenogenetically into
male drones. If the sperm
fertilize the egg it will
develop to either future
queen or female worker.
ANIMAL REPRODUCTION
6.3

Sexual
Reproduction in
Animals
Sexual Reproduction in Animals
• Gametogenesis: production of gametes
• Spawning or mating: bringing gametes together
• Fertilization: fusion of gametes
Higher forms of animals
mostly reproduce
asexually. Which means
that individuals are
formed from gametes
Yeah, the testes produce the
male gametes and ovaries
produce the female gametes.
ANIMAL REPRODUCTION
6.3

Sexual
Reproduction in
Animals
Animals that can change their sex in response to social or environmental challenges
undergo a process known as sequential hermaphroditism or sex reversal.
•Protandry – a change from male to female.
•Protogyny - a change from female to male.
Some animals that
possesses both male and
female organs are called
HERMAPHODITES
SELF CHECK!
What is the advantage of animals having both asexual and
sexual reproduction?
ANIMAL REPRODUCTION
6.3

Sexual
Reproduction in
Animals
In most species individuals
have gonads, organs
that produce gametes.
The mechanisms of
fertilization, the union
of egg and sperm, play
an important part in
sexual reproduction
In external fertilization,
eggs shed by the
female are fertilized by
sperm in the external
environment
ANIMAL REPRODUCTION
6.3

Sexual
Reproduction in
Animals
In internal fertilization, sperm are deposited in or near the female reproductive tract,
and fertilization occurs within the tract
Internal fertilization requires behavioral interactions and compatible copulatory organs
All fertilization requires critical timing, often mediated by environmental cues,
pheromones, and/or courtship behavior
ANIMAL REPRODUCTION
6.3

Sexual Reproduction in Animals
•An animal that deposits its eggs in the
external environment is called oviparous.
•Animal that retain their eggs in their
bodies and release their young to fend
for themselves is called ovoviviparous.
•Animals that do not lay eggs but rather
the young develops inside the mother’s
body until they mature and live
independently are called viviparous.
Time for Concept Check!
Describe external fertilization in lower
froms of animals
ANIMAL REPRODUCTION
6.3

LESSON
6.4
Human Reproduction
Human reproduction is controlled by hormone
cycles and proceed through distinct
developmental stages.
The male’s external reproductive organs
are the scrotum and penis
Internal organs are the gonads, which
produce sperm and hormones, and
accessory glands
HUMAN REPRODUCTION
6.4

•The male gonads, or testes, consist of
highly coiled tubes surrounded by
connective tissue.
•Sperm form in these seminiferous
tubules.
•Leydig cells produce hormones and are
scattered between the tubules.
•Production of normal sperm cannot occur
at the body temperatures of most
mammals.
•The testes of many mammals are held
outside the abdominal cavity in the
scrotum, where the temperature is lower
than in the abdominal cavity.
HUMAN REPRODUCTION
6.4

DUCTS
From the seminiferous
tubules of a testis, sperm
pass into the coiled
tubules of the epididymis
During ejaculation, sperm
are propelled through the
muscular vas deferens
and the ejaculatory duct,
and then exit the penis
through the urethra
HUMAN REPRODUCTION
6.4

Accessory Glands
•Semen is composed of sperm plus secretions from three sets of
accessory glands
•The two seminal vesicles contribute about 60% of the total volume of
semen
•The prostate gland secretes its products directly into the urethra
through several small ducts
•The bulbourethral glands secrete a clear mucus before ejaculation that
neutralizes acidic urine remaining in the urethra.
HUMAN REPRODUCTION
6.4

HUMAN REPRODUCTION
6.4

SPERM ANATOMY
Sperm develop in the testes and
consist of a head, a midpiece, and a
tail. The head contains the nucleus
with densely coiled chromatin
fibers, surrounded anteriorly by an
acrosome that contains enzymes
for penetrating the female egg. The
midpiece has a central filamentous
core with many mitochondria
spiraled around it
HUMAN REPRODUCTION
6.4

Spermatogenesis
The Process OF
• Spermatogenesis begins with a diploid
spermatogonium in the seminiferous tubules, which
divides mitotically to produce two diploid primary
spermatocytes.
• The primary spermatocyte then undergoes meiosis
I to produce two haploid secondary spermatocytes.
• The haploid secondary spermatocytes undergo
meiosis II to produce four haploid spermatids.
• Each spermatid begins to grow a tail and a
mitochondrial-filled midpiece, while the chromatin is
tightly packaged into an acrosome at the head.
HUMAN REPRODUCTION
6.4

• Maturation removes excess
cellular material, turning
spermatids into inactive,
sterile spermatozoa that are
transported via peristalis to
the epididymus.
• The spermatozoa gain
motility in the epididymus,
but do not use that ability
until they are ejaculated into
the vagina.
HUMAN REPRODUCTION
6.4

SEMEN Semen is an organic fluid, also known as
seminal fluid, that may contain spermatozoa. It
is secreted by the gonads (sexual glands) and
can fertilize female ova. In humans, seminal
fluid contains several components besides
spermatozoa, including enzymes (proteolytic
and others) and fructose. These elements
promote the survival of spermatozoa and
provide a medium for motility. Semen is
produced and originates from the seminal
vesicles, located in the pelvis. The process that
results in the discharge of semen is called
ejaculation.
HUMAN REPRODUCTION
6.4

Before you can proceed to
the next lesson you need o
answer the question
CONCEPT CHECK
Explain the process of spermatogenesis
HUMAN REPRODUCTION
6.4

FEMALE REPRODUCTIVE SYSTEM
•The female external reproductive
structures include the clitoris and two
sets of labia
•The internal organs are a pair of
gonads and a system of ducts and
chambers that carry gametes and
house the embryo and fetus.
HUMAN REPRODUCTION
6.4

•The onset of egg production
starts in puberty, during the first
discharge of blood from the
vagina or first menstruation
(called the menarche).
•An egg that matures is called an
ovum.
•Inside the ovaries, the follicle-
stimulating hormone (FSH) and
luteinizing hormone (LH)
stimulate the production of
another hormone called estrogen.
•Estrogen has three functions:
a. To develop the sexual characteristic
b. To help in the maturation of the egg cell
c. To prepare the uterus for pregnancy each
month.
HUMAN REPRODUCTION
6.4

•The mature egg cell travel for three to four days into one of the
fallopian tube known as oviduct or uterine tubes.
•If the egg was fertilized it will travel down and attach itself to the inner
wall of the uterus, called the endometrium.
•The lower end of the uterus is called the cervix and opens into a tube
called the vagina.
•The vagina is a thin-walled chamber that is the repository for
sperm during copulation and serves as the birth canal.
•The vagina opens to the outside at the vulva, which consists of
the labia majora, labia minora, hymen, and clitoris.
•The clitoris has a head called a glans covered by the prepuce.
•The vagina, labia minora, and clitoris are rich with blood
vessels; the clitoris also has many nerve endings.
HUMAN REPRODUCTION
6.4

The mammary glands are not part of the reproductive system but are
important to mammalian reproduction
Within the glands, small sacs of epithelial tissue secrete milk.
SELF CHECK
Contrast the structures of the human male and
female reproductive system
HUMAN REPRODUCTION
6.4

The Human
Reproductive
Process
TIME FOR NEXT ADVENTURE AND YOU
WILL MEET BMO ALONG THE WAY!
All females at the mature
age will undergo two
interrelated monthly
psychological cycles knows
as the ovarian and
menstrual cycles WELCOME TO MY HOUSE!
I WILL TEACH YOU THE
NEXT LESSON. ARE YOU
READY?
HUMAN REPRODUCTION
6.4

The ovarian cycle controls the maturation
timing of the oocyte in the ovaries. It is
responsible for the monthly release of
the egg from the ovary, called ovulation.
It has two phases:
a) The follicular phase begins with the
release of the FSH and LH which
stimulates the production of
estrogen, which aids in the growth of
the follicle.
b) The luteal phase, LH causes the
raptured cells of the follicle to form a
corpus luteum – a mass of yellowish
follicular cells that secrete both
estrogen and progesterone.
Ovarian Cycle
HUMAN REPRODUCTION
6.4

Menstrual cycle prepares the body for
pregnancy which lasts for an average of
28 days. If pregnancy does not occur,
the levels of estrogen and
progesterone go down, causing the
lining of the uterus to shed, marking
the end of the menstrual cycle. An
unfertilized egg will disintegrate and
leave the body together with the shed
lining of the uterus during
menstruation. A woman who stops
menstruating usually happens at the
age of 45 to 55 has reached a stage in
her life known as menopause.
Menstrual Cycle
HUMAN REPRODUCTION
6.4

Fertilization begins with the fusion of the
sperm and the egg cell to form a fertilized
egg called a zygote. A series of cell
divisions will take place as the zygote
travels down the fallopian tube toward
the uterus. The zygote then becomes a
ball of cells that attaches itself to the wall
of the uterus in the process called
implantation. At this point, the zygote is
called an embryo.
HUMAN GROWTH AND
DEVELOPMENT
FERTILIZATI
ON
HUMAN REPRODUCTION
6.4

Before you can proceed to
the next lesson you need o
answer the question
CONCEPT CHECK
At what point in the ovarian cycle are estrogen
and progesterone levels highest?
HUMAN REPRODUCTION
6.4

The human gestation takes about
nine months from the time the
embryo is implanted in the uterus
until it is born. During the first
two months, the developing child
is called an embryo.
The umbilical chord is formed that
transports nutrients and carry
away wastes. A thin membrane
called amiotic sac that contains
amiotic fluid develops at the third
week of pregnancy, which helps in
cushioning the protecting the
embryo.
HUMAN GROWTH AND
DEVELOPMENT
Embryonic
Development
HUMAN REPRODUCTION
6.4

At this stage, at the third month the embryo is now called a fetus. Fingers, eyes nose arms, legs
and other major organs will now form. Heartbeat can now also be detected. In the fourth month,
gender of the baby can now be determined. By the end of the seventh month fetal bones begin to
harden. By the eight month the fetal development nears completion. The brain and lungs grows
rapidly. The bones on the head are soft so that it can easily pass through the birth canal.
HUMAN GROWTH AND
DEVELOPMENT
Fetal Development
HUMAN REPRODUCTION
6.4

The process of giving birth is also known as paturition. By the ninth month, the fetus has rotated to a
head-down position but when it is feet-down position it is called a breech birth and it is very dangerous.
The birth process begins with the onset of a series of mascular contractions of the uterus called labor
stimulated by oxytocin. As the contraction become stronger and closer in succession, the amiotic sac
usually breaks and its fluids will be released. After birthing, the placenta is expelled.
HUMAN GROWTH AND
DEVELOPMENT
Birth
HUMAN REPRODUCTION
6.4

Congratulations you have
finished the lesson!
HUMAN REPRODUCTION
6.4

ASSESMENT PART
0.0
The Princess has been kidnapped by
the Evil Ice king. Helped us rescue her
by completing the assessment part!
Good luck.
NO ONE CAN BEATME!
HAHAHAH

ASSESMENT PART
0.0
YOUCANNOTANSWER
THAT. HAHAHAHA
Assessment Questions
1. What is the process whereby an animal contains both
ovaries and testes and can thus produce both eggs and
sperms
a. Budding
b. Hermaphrodotism
c. Fission
d. parthenogenesis

ASSESMENT PART
0.0
YOURANSWERIS
WRONG. HAHAHAHA
GO BACK TO THE
QUESTION

ASSESMENT PART
0.0
OH NO, AHHHHHHH
GRRRRR

ASSESMENT PART
0.0
YOUCANNOTANSWER
THAT. HAHAHAHA
2. Plant tissue culture centers on the plant’s ability of______
a. Floral arrangement
b. Phototropism
c. Sexual Reproduction
d. Totipotency

ASSESMENT PART
0.0
YOUCANNOTANSWER
THAT. HAHAHAHA
3. During germination, the first to appear from the seed is
the_______
a. Leaf
b. Root
c. Shoot
d. Stem

ASSESMENT PART
0.0
YOUCANNOTANSWER
THAT. HAHAHAHA
4. Gametes required for fertilization are produced during
_______
a. Implantation
b. meiosis
c. mitosis
d. ovulation

ASSESMENT PART
0.0
YOUCANNOTANSWER
THAT. HAHAHAHA
5. One advantage of genetic engineering for agriculture is
_______
a. Curing genetic diseases
b. Increasing yield
c. Mass production of plants
d. Cloning plants

ASSESMENT PART
0.0
YOUCANNOTANSWER
THAT. HAHAHAHA
6. A function of a fruit is to__________
a. Attract pollinators
b. Nourish embryo development
c. Help in seed dispersal
d. Sign plant maturity

ASSESMENT PART
0.0
YOUCANNOTANSWER
THAT. HAHAHAHA
7. Fruits are formed from a flower’s__________
a. ovary
b. Petals
c. Seeds
d. Stigma

ASSESMENT PART
0.0
YOUCANNOTANSWER
THAT. HAHAHAHA
8. Sexual reproduction in flowering plants requires___________
a. Bulbs
b. Pollens
c. Rhizomes
d. Tubers

ASSESMENT PART
0.0
YOUCANNOTANSWER
THAT. HAHAHAHA
9. Sex organs mature rapidly during____________
a. Adulthood
b. Childhood
c. Puberty
d. Infancy

ASSESMENT PART
0.0
YOUCANNOTANSWER
THAT. HAHAHAHA
10. The process involved when the egg is released from the ovary is known
as___________
a. Ejaculation
b. Fertilization
c. Menstruation
d. Ovulation

ASSESMENT PART
0.0
OH NO, AHHHHHHH
GRRRRR
YOU RESCUED THE
PRINCESS
CONGRATULATIONS!

REFERENCES
•Morales-Ramon and A.C., Ramon, B.J. (2012). General Biology 2: Exploring Life Through
Science. Phoenix publishing house. Pg 175-207.
•Campbell, N., Cain, M., Minorsky, P., Reece, J., Urry, L. and Wasserman, S.,
(2013). Biology. 10th ed. pp.1233-1250.

Genbio 2 chapter 6 (perpetuation of life) harold morales

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Similar to Genbio 2 chapter 6 (perpetuation of life) harold morales

Similar to Genbio 2 chapter 6 (perpetuation of life) harold morales (20)

Recently uploaded

Recently uploaded (20)

Genbio 2 chapter 6 (perpetuation of life) harold morales