3.21b Genetic Probabilities

3.21a Genetic Probabilities

3.20b Pedigree 2

3.20a Pedigree diagrams

3.18c Codominance

3.19b F1xF1 Cross

• The parents is red petal cross with white petal. We will carry out and F1 cross and this involve reproduction between F1 parents and F1 parents.
• We begin by writing the phenotype is red petal cross another red petal.
• Genotype combination of allele. One would be carrying R and another one would be carrying r.
• Cell would go under process meiosis. Chromosomes number is half and allele is separate.
• Genotype F2 RR:2Rr:rr
• Phenotype F2 2 red: white   3 red: 1 white <--- prediction ratio
• Monohybrid ratio F2 3:1 3 red : 1 white

3.19a P1xP1 Cross

Individual gene = 2 alleles

1.  Cross homozygous red petal plant x white petal plant.
2. Allele key R-red r-white R>r
3. Parental phenotype red petal plant x white petal plant
4. Parental Genotype is homologous pair of chromosomes RR x rr
5. This process is meiosis and production of gametes
6. Random fertilisation

	r	r
R	Rr	Rr
R	Rr	Rr

offspring genotype Rr
offspring phenotype all red F1=all Rr  (Heterozygous)

3.18b Genotypes

• The appearance is control by the Genotype and the Genotype is a combination of 2 alleles.

Allele key: R-red, r-white

Allele combination	Genotype	Phenotype
Homozygous (same allele)	RR	Red
	rr	White
Heterozygous (different allele)	Rr	Red

(dominant of R)
(r-recessive)

3.18a Phenotypes

• Phenotype are what we can see. If we take a red petal plant and reproduce with another red petal plant. The offspring when germinate and growing flower to produce red petals.
• The phenotype is red.
• If we take white petal plant and reproduce with another white petal plan. The offspring germinate and growing flower to produce white petals
• If we take the white petal plant and cross section with the red petal plant and the it would be red.
• We would say that the red is dominant and the white is recessive..

Board notes

3.2 Fertilisation

• Process begun with adult male and adult female. The cell which made up an adult whether is male or female.
• These cells has a complete chromosomes. One is diploid which is from the adult male and contain 2n=42 chromosomes for human. These cell divide in a testy.
• Type division is meiosis. Female the cell meiosis would contain haploid.
• They both join/fuse together and the process is fertilisation. New cell known as a zygote.
• The process cell division is mitosis eg. one cell will divide to 2 cell and both contain 46 chromosomes. Efficient cell structure would call embryo.

3.10 Menstrual Cycle

• Oestrogen and progesterone are both example of hormones.
• Hormones is produce in a structure of endocrine gland, hormones will travel through the blood to it target which is tissues. Target tissues hormones will effect.
• The ovary produces oestrogen which has effect of the thickness and effect number 2. is the effect to the brain which causes the ovary to release an egg.
• Produces progesterone.
• The end of the cycle is menstrual period.

3.9b Female Reproductive System

Structure	Function
Ovary	Meiosis occurring and production of egg
Oviducts	Carry egg to uterus
Uterus	Wall of uterus made of muscle. Stretch when pregnancy and contract when birth
Lining of uterus	Fertilize the egg to the embryo and the child are develop of placenta
Uterus space	Place where embryo develop to unborn child
Cervix	Entrance to the uterus
vagina	Collect sperm cells, allow them to the cervix and the uterus

3.9a Male Reproductive System

Structure	Function
Bladder	Store urine
Testis	Meiosis gamete sperms
Epididymis	Store sperm cells
Vas deferens	Sperm cells to penis
Prostate	20-30% semen which is known to contain sugar and alkali
Seminal vesicles	70% semen which is known to contain sugar and alkali
Urethra	Semen down to penis
penis	Carry sperm cells to vagina during sexual intercourse

3.12 Amniotic Fluid

Am

• Surrounding the uterus space is a fluid and that fluid is called "Amniotic fluid".
• It can protect the developing embryo.
• The fluid which is largely water.
• The amniotic fluid cannot be compressed ans when we try to squeezed the fluid, it absorbs the pressure.
• Any blows/forces applied to the uterus wall, the amniotic fluid will absorbs this pressure to prevent damage to the unborn child.

3.11 Placenta

• The uterus and on one side of the uterus wall is called "Placenta". The Placenta structure is embryo is at the end. The Placenta grows of the developing embryo.
• Placenta is growing to the wall of the uterus.
• In the mother blood has glucose, amino acids and fats. These will travel through the mother blood stream to the uterus.
• Will cross to the child blood through the Placenta. Placenta has large surface area.
• Child exchange food to CO2 and urea.