Reproduction

What is reproduction?

Reproduction is the biological process by which living organisms produce offspring.

Reproduction is essential for the survival of a species.

It allows genetic information to be passed from one generation to the next.

Sexual reproduction

• Genetic information comes from two parents

• Offspring usually have different combinations of characteristics

Asexual reproduction

• Genetic information comes from one parent

• Offspring are usually genetically very similar to the parent

Sexual reproduction examples

Most animals and plants, including humans and flowering plants.

Asexual reproduction examples

Some animals and plants, including starfish and strawberries.

What does the male reproductive system produce and deliver?

The male reproductive system produces and delivers sperm.

What does the female reproductive system produce and support?

The female reproductive system produces egg cells and supports fertilisation.

What is the role of the male reproductive system?

1. Produce healthy sperm

2. Transport sperm through the reproductive system

3. Deliver sperm to the female reproductive system

Why is transport an important role of the male reproductive system?

Transporting sperm is important because sperm need to reach the female reproductive system to fertilise an egg cell. This allows reproduction to occur.

How does the female reproductive system contribute to reproduction?

1. Producing egg cells

2. Receiving sperm

3. Allowing fertilisation to occur

4. Supporting early development after fertilisation.

How does the female reproductive system support reproduction after producing an egg cell?

• facilitating sperm to reach the egg cell.

• assisting fertilisation. 

• providing a place where early development of offspring can begin.

Bladder

Seminal vesicle

Prostate gland

Sperm duct/Vas deferens

Anus

Urethra

Penis

Testes

Scrotum

Function of testes

Produces sperm and testosterone.

Function of scrotum

Holds the testes outside the body. Keeps the testes at a slightly lower temperature then the rest of the body/regulates the temperature

Function of vas deferens

Transports sperm toward the urethra.

Function of urethra

The tube inside the penis through which semen leaves that male’s body

Function of penis

Swells during sexual arousal. Semen containing sperm cells is ejaculated from the penis into the vagina

Function of seminal vesicle

Adds sugar-rich fluid that provides energy for sperm.

Function of prostate

Secretes some of the fluid that is added to sperm to make semen. This fluid is alkaline and full of enzymes, helping to keep the sperm cells alive once they enter the vagina.

Function of epididymis

Stores sperm and allows them to mature. Sperm develop the ability to move and fertilise an egg cell.

What is the sperm pathway?

testes → epididymis → vas deferens → urethra → penis (Along the way, fluids from the seminal vesicles and prostate gland are added to form semen)

How do the structures of the male reproductive system work together to move sperm out of the body?

Sperm are produced in the testes, then move to the epididymis, where they mature and are stored. They travel through the vas deferens, mix with fluids to form semen, and leave the body through the urethra and penis.

If one part does not function correctly, it can affect:

• sperm production

• sperm storage or maturation

• sperm transport

• semen delivery

Testosterone

a hormone produced by the testes.

What is a hormone

A hormone is a chemical messenger that helps control processes in the body.

In the male reproductive system, testosterone supports:

• sperm production

• male reproductive development

• the functioning of the male reproductive system

Fallopian tube/oviducts

Ovary

Uterus

Cervix

Anus

Vagina

Hymen

Vulva

Clitoris

Urethra

Bladder

Function of ovaries

Produce ova. One egg is produced about once a month from one ovary. They also release hormones such as oestrogen and progesterone

What does oestrogen and progesterone do

regulates the reproductive cycle and prepare the body for possible pregnancy.

what does oestrogen and progesterone help control

• the release of an egg.

• initial growth and thickening of the uterine lining.

Function of fallopian tubes

Tube the ova travels from the ovaries into the uterus. This is where fertilization happens.

Function of uterus

Where the embryo implants and a baby develops. Its lining (endometrium) thickens in preparation for possible implantation.

Function of cervix

The passageway between the vagina and the uterus, allows sperm to enter. During childbirth the cervix dilates (opens) to allow the baby to leave the uterus. 

Function of vagina

Elastic tube that connects the uterus to the outside world through which semen enters the female reproductive system. 

Function of clitoris

Swells during sexual arousal and becomes highly sensitive when erect

What is the bladder and urethra a part of

the excretory system.

What is

the function of the fimbriae

catch mature eggs released during ovulation and guide them inside the fallopian tube

the function of the ovarian ligaments

hold the ovaries in place.

egg pathway:

ovary → fallopian tube → uterus

sperm entry pathway:

vagina → cervix → uterus → fallopian tube

Where does fertilisation typically occur?

Fertilisation typically occurs in the fallopian tube if sperm are present.

what happens to the uterine lining if fertilisation does not occur

the uterine lining breaks down and leaves the body. This process is called menstruation.

What are gametes

A haploid/sex cell with 23 chromosones. Examples include the ovum and sperm

What is the male gamete

Sperm cells

What is the female gamete

Egg cells

What is a zygote

A fusion of the nucleus and sperm, with 46 chromosones

Sperm specialised structure:

Sperm are small, mobile, and streamlined so they can travel to reach the egg. 

Egg specialised feature

Eggs are larger and contain stored nutrients and resources to support the early development of a new organism after fertilisation.

Label the sperm

a) head, b) tail c) nucleus d) midpiece

Function of sperm head

contains genetic material and enzymes, which helps the sperm digest and break through outer layers of the egg to fertilise it

function of sperm midpiece

packed with mitochondria, which helps it to generate energy for movement, because the sperm needs a constant energy supply to swim.

function of sperm tail

long and whip-like, which helps it to propel the cell forward

label the egg cell

Corona radiata

consists of follicular cells. These cells play a role in nourishing and protecting the egg.

Zona pellucida

s composed of glycoproteins and provides structural support to the egg. It also plays a crucial role in sperm-egg interaction during fertilization.

Vitelline membrane

is the innermost layer. This membrane provides additional protection to the egg.

egg cytoplasm

contains essential reserves in the form of yolk which provides essential proteins, lipids, and other nutrients necessary for early development.

Internal Fertilization

In animals that live and breed on land, internal fertilisation occurs. This keeps the gametes inside the body so there is no chance of dehydration occurring. In this situation, sperm are introduced into the female by a process called copulation (or sexual intercourse).

External Fertilization

In some animals, especially those that live or breed in water such as fish and amphibians, fertilisation occurs outside the female’s body. In this situation, the female releases her unfertilised eggs into the water to be fertilised by the male’s sperm, which are also released into the water.

What is variation?

Variation is the differences in physical traits, genes, or behaviors amongst a population

Examples of variation

• Height

• Eye colour 

• Body size

• Resistance to disease

• Fur colour

Is asexual reproduction mitosis or meiosis

mitosis

Is sexual reproduction mitosis or meiosis

meiosis

Factors that can change about the environment include:

Temperature changes, changes in food availability, new diseases

What are alleles

forms of genes

Asexual reproduction is an effective method for:

• - No mate required
  - Faster process
  - Energy and time efficient

Disadvantages of Asexual Reproduction

- No genetic variation
- Same disease resistances
- Risk of overpopulation due to reproduction speed

Advantages of Sexual Reproduction

• Genetic Variation

• Disease resistance

• Eliminates harmful mutations

Disadvantages of Sexual Reproduction

- High energy and time demand
- Requires 2 parents
- Slower rate of reproduction

What are the three types of Asexual Reproduction?

binary fission, fragmentation, and budding

Fragmentation

Fragmentation occurs when part of an organism separates from the parent and develops into a new individual.

Budding

Budding occurs when a small outgrowth, called a bud, forms on the parent’s body.

Fission

Fission occurs when one organism divides into two separate individuals. 

label the flower

What does the ovule and ovum become after flower fertilisation

ovule, seed. ovary, fruit

stamen

filament + anther

carpel

stigma + style + ovary

List 3 different methods of pollination

Insect pollinated, wind pollinated, water pollinated

Insect pollination

Plants lure insects using bright petal colors, ultraviolet patterns, sweet or putrid scents, and sugary nectar rewards to pollinate them.

Wind pollination

plants use air currents to transfer pollen from male to female reproductive structures without needing insect or animal vectors

Water pollination

a rare form of plant reproduction where water currents act as the medium to transfer pollen from male flowers to female flowers

What is Vegetative Propagation?

Asexual reproduction in plants