Reproduction Or at least the parts that are tested…

First: What is the difference between Asexual Reproduction and Sexual Reproduction? When you put “a-” in front of a word it usually means “without” “Asexual reproduction” means reproduction without sex.

When you put “a-” in front of a word it usually means “without” “Asexual reproduction” means reproduction without sex. Sexual Reproduction= 2 parentsAsexual Reproduction= 1 parent

When you put “a-” in front of a word it usually means “without” “Asexual reproduction” means reproduction without sex. Sexual Reproduction= 2 parentsAsexual Reproduction= 1 parent Gametes from the two parents are combined to form offspring that are different from each other AND their parents

When you put “a-” in front of a word it usually means “without” “Asexual reproduction” means reproduction without sex. Sexual Reproduction= 2 parentsAsexual Reproduction= 1 parent Gametes from the two parents are combined to form offspring that are different from each other AND their parents

When you put “a-” in front of a word it usually means “without” “Asexual reproduction” means reproduction without sex. Sexual Reproduction= 2 parentsAsexual Reproduction= 1 parent Gametes from the two parents are combined to form offspring that are different from each other AND their parents The single parent can usually only produce clones of itself…

When you put “a-” in front of a word it usually means “without” “Asexual reproduction” means reproduction without sex. Sexual Reproduction= 2 parentsAsexual Reproduction= 1 parent Gametes from the two parents are combined to form offspring that are different from each other AND their parents The single parent can usually only produce clones of itself…

Sexual Reproduction= 2 parentsAsexual Reproduction= 1 parent Gametes from the two parents are combined to form offspring that are different from each other AND their parents The single parent can usually only produce clones of itself… Provides Genetic Diversity and greater survivability for the species Usually Faster, and 100% of the genes of an individual are passed on

Sexual Reproduction= 2 parentsAsexual Reproduction= 1 parent Provides Genetic Diversity and greater survivability for the species Faster, and 100% of the genes of an individual are passed on ALL organisms Yes, I said ALL! can do this As you know, there are animals that can’t do this

What is a Gamete? Most of the cells of a Human being has 46 chromosomes, and are called Diploid. Human Gametes are cells that have only 23 chromosomes, and are called Haploid Have you figured it out yet?

What is a Gamete? Most of the cells of a Human being has 46 chromosomes, and are called Diploid. Human Gametes are cells that have only 23 chromosomes, and are called Haploid Have you figured it out yet? Sex Cells

What is a Gamete? Most of the cells of a Human being has 46 chromosomes, and are called Diploid. Human Gametes are cells that have only 23 chromosomes, and are called Haploid Have you figured it out yet? Sex Cells AKA: Eggs and Sperm

Are animals the only ones with Gametes?

Of course NOT. Plants and fungi have their own forms of eggs and sperm, some of them spend most of their lives AS “eggs” and “sperm” Protists are so weird don’t be surprised about anything that they can do. Bacteria are so plentiful and variable that they can do almost anything. They have ways of reproducing that we can barely imagine…

But you DO need to know about plants… Flowers=Angiosperms Flowers  Fruits Cones= Gymnosperms BTW: Pollen IS Sperm

So where are human Gametes made? Gametes are made during meiosis (more on that in February…) Eggs cells are made in the _______ Sperm cells are made in the ________

So where are human Gametes made? Gametes are made during meiosis (more in that in February…) Eggs cells are made in the _______ Sperm cells are made in the ________ Ovaries! Testes!

Let’s follow the sperm first…

Where are sperm made?

Where are sperm Stored?

Which of the following makes the fluid that the sperm swim in (semen)?

What is the tube that sperm travel through on their way to the penis?

What is the tube that sperm and urine travel through on their way out of the body?

The Female

Here’s another view…

So what’s going on in there? Every little girl is born with about 40,000 immature eggs in two ovaries. They begin to die off and she usually has only a couple of thousand by the time she starts puberty. Once a month until menopause, her ovaries will pick one of the eggs to grow into maturity. When it is ready the egg is released—called ovulation. The part left behind—the corpus luteum—then releases chemical signals that regulate the menstrual cycle.

On the male side… Sperm are made fresh every day starting at puberty—often till death. They are stored in the Epididymis for about 4-5 days. If they aren’t “used” they are broken down and reabsorbed back into the body.

So what does that mean for you? The part of you that came from your dad is probably no more than a couple of days older than you. The part of you that came from your mom is older than her.

Eggs vs. Sperm Scientists decide whether an organism is a male or a female by looking at who makes the eggs. How do you know its an egg?

Eggs vs. Sperm Scientists decide whether an organism is a male or a female by looking at who makes the eggs. How do you know its an egg? – The larger gamete The larger the gamete, the more “expensive” it is to make, so there are less of them. Generally the parent that puts more effort into its offspring has fewer of them. This parent is usually called the “female”

So after ovulation the egg leaves the ovary and will be gently picked up by the Fimbriae and begin its passage down the fallopian tubes (aka the oviduct).

Fertilization happens in the Fallopian tubes (oviduct). Sperm can live for a few days in the fallopian tubes waiting for an egg to show up.

Once the Egg is fertilized it is called a Zygote and it starts to divide. When it becomes a hallow ball of cells it is called a blastocyst (or blastula).

The blastula implants into the endometrial layer of the uterus—this begins pregnancy. Then the blastula starts to fold inward and the cells start to differentiate and form the three germ layers of the new organism.

At first the Embryo feeds off of nutrients stored in the yolk sac as the placenta develops. Eventually it will live completely off of the nutrients provided by the placenta from the mother’s blood. It is called a Fetus at the end of the eighth week.

Highlights of Fetal development 1 st trimester 5 weeks: heart starts to beat 6 weeks: arm and leg buds start to appear 8 weeks: fingers, toes, nose, and upper lip 9 weeks: eyes develop, eye lids are still fused, tail gone 10 weeks: many organs start to function, finger and toe nails start to grow

14 weeks: facial expressions, maybe thumb sucking 15 weeks: can sense light but eyes are still closed 16 weeks: sex can be determined by ultrasound 18 weeks: mother may begin to feel movement 19 weeks: baby can hear 24 weeks: taste buds develop, hair may be growing 27 weeks: practicing breathing Highlights of Fetal development 2 nd trimester

Highlights of Fetal development 3 rd trimester 28 weeks: dreaming? Eyelashes ready, eyesight improving, growing fast, lungs not ready yet 34 weeks: almost ready to be born but would spend a couple of days in the neonatal unit 37 weeks: considered “done” 40 weeks: considered “due” 40+ weeks: considered “overdue” or “well done” – Mother is considered “cranky”

During labor the muscular uterine walls contract—getting stronger and stronger—forcing the baby downwards. The Cervix gets softer, shortens, and widens to 10 cm. After the baby is born the placenta detaches itself and follows.