3.19b - F1 x F1 Cross

3.19a - P1 x P1 Cross

3.18c - Codominance

3.18b - Genotype

3.18 - recall the meaning of the terms: dominant, recessive, homozygous, heterozygous, phenotype, genotype and codominance 

3.18a - Phenotypes

3.18 - recall the meaning of the terms: dominant, recessive, homozygous, heterozygous, phenotype, genotype and codominance 

2.4 - Plant and Animal Cells

Animal Cells and Plant Cells have a:

Nucleus 

Cytoplasm 

Cell Membrane 

Only Plant Cells have: 

Cell Wall 

Chloroplasts 

Central Vacuole - additional storing 

- Plant Cells Shape is more Regular 

- Animal Cells store carbohydrate as glycogen 

- Plant Cells store carbohydrate as starch 

Circle Of Life

3.12 - Amniotic fluid

In the uterus space there is the amniotic fluid

functions: 

- can protect the developing embryo - comes from the fluid  (largely water) not being able to be compressed. 

- When you try to squeeze the fluid it absorbs the pressure. 

- This means any blows or force applied to the uterus wall - the amniotic fluid will absorb this pressure and will prevent damage to the unborn child. 

example of absorbing the pressure: 

in a swimming pool when you try to kick it with your leg - leg doesn't move very quickly, hard to generate great force. - example of how the fluid absorbs the force. 

3.11 - Placenta

when the child is in the uterus - water filled environment (amniotic fluids) - child cannot digest or breath or excrete

- baby obtains food - blood vessels lead from the embryo down the umbilical cord and then spread out to form placenta. 

- placenta biologically grows out of the developing embryo. not out of the mother. 

- blood vessels inside the placenta are the child's (veins and arteries) 

- placenta grows into the lining of the uterus (wall) 

- mother continues to eat and so in the blood vessel we have things like glucose, amino acids and fats. these travel through blood stream and into the wall of the uterus. they then cross into the childs blood at the placenta. 

- to make this efficient the placenta has a large surface area and the barrier between the mother and childs blood is very thin. 

- child produces CO2 and Urea which then goes back into the mothers blood. 

3.9b - Female Reproductive System

before a pregnancy occurs the uterus structure is no larger then an orange.

Ovary - meiosis occurs and production of female gamete(eggs) 

Oviducts - carry the eggs to the uterus and where fertilization takes place. where sperm cells meet the egg cells. 

Uterus - wall of the uterus is made of muscle. stretches to accommodate pregnancy and contracts during birth. 

Lining of the uterus - develops the fertilized egg into the embryo and then the child. can see the development here of the placenta 

Cervix - entrance to the uterus - where sperm cells enter. 

Uterus space - where the sperm and egg cells move. Embryo develops into the unborn child

Vagina - collects the sperm cells and allows them to pass throw the cervix into the uterus 

3.9a - Male Reproductive System

Bladder - Store urine 

Testis - 2 of them - carry out meiosis - produces the gamete, sperm 

epididymis - stored sperm cells 

vas deferens - carry sperm cells to the penis during sexual stimulation. the tube pulses making the walls contract and push the sperm from the testis to the penis

prostate - adds about 20/30% of the volume of the semen. contains sugars and is alkali. 

Seminal Vesicles - 70& of the volume of the semen. contains sugars and is alkali 

When sperm cells are combined with the prostate and seminal vesicles secretions we have semen. - carried forward and down to the urethra 

Urethra - common tube that joins the left and right testis. takes semen/urine down the penis

Penis - carries sperm cells into the vagina during sexual intercourse