(I)GCSE Topic 3.12 Amniotic Fluid

*The developing Embryo is protected by the Amniotic Fluid*

- Protection of the developing Embryo comes from comes from the fact that the fluid (largely water) cannot be compressed.

- Fluid Absorbs the pressure - prevent damage to the unborn child. 

(I)GCSE Male and Female

Primary -> Secondary FEMALE    

Begin to develop at the age of 13/14

Hips Widen 

Weight / Fat 

Facial Structure 

Breast 

Height

Period 

Body Hair 

Primary -> Secondary MALE    

Begin to develop at the age of 14/15

Voice

Facial Hair 

Weight 

Chest Hair 

Bone Widen / Grow 

Increase in Muscle 

(I)GCSE Topic 3.11 Placenta

The role of the Placenta in the nutrition of the Developing Embryo =
- When the child is in the uterus, it cannot digest, breathe, excrete
- Child digests through placenta structure / Umbilical Cord
- Placenta, biologically grows out of the embryo - not the mother
- Blood vessel inside the placenta are the child's blood vessels including the arteries and veins
- Glucose, Amino Acids, Fats inside mothers blood vessels cross into child's blood - crossing at the placenta.

Klinefelter's Syndrome

Interpreting the karyotype Lab technicians compile karyotypes and then use a specific notation to characterize the karyotype. This notation includes the total number of chromosomes, the sex chromosomes, and any extra or missing autosomal chromosomes. For example, 47, XY, +18 indicates that the patient has 47 chromosomes, is a male, and has an extra autosomal chromosome 18. 46, XX is a female with a normal number of chromosomes. 47, XXY is a patient with an extra sex chromosome. B 1. What notation would you use to characterize Patient B's karyotype? Making a diagnosis The next step is to either diagnose or rule out a chromosomal abnormality. In a patient with a normal number of chromosomes, each pair will have only two chromosomes. Having an extra or missing chromosome usually renders a fetus inviable. In cases where the fetus makes it to term, there are unique clinical features depending on which chromosome is affected. Listed below are some syndromes caused by an abnormal number of chromosomes. B 2. What diagnosis would you give patient B? Diagnosis Chromosomal Abnormality Normal # of chromosomes patient's problems are due to something other than an abnormal number of chromosomes. Klinefelter's Syndrome one or more extra sex chromosomes (i.e., XXY) Down's Syndrome Trisomy 21, extra chromosome 21 Trisomy 13 Syndrome extra chromosome 13

Down's Symdrome

Interpreting the karyotype Lab technicians compile karyotypes and then use a specific notation to characterize the karyotype. This notation includes the total number of chromosomes, the sex chromosomes, and any extra or missing autosomal chromosomes. For example, 47, XY, +18 indicates that the patient has 47 chromosomes, is a male, and has an extra autosomal chromosome 18. 46, XX is a female with a normal number of chromosomes. 47, XXY is a patient with an extra sex chromosome. A 1. What notation would you use to characterize Patient A's karyotype? Making a diagnosis The next step is to either diagnose or rule out a chromosomal abnormality. In a patient with a normal number of chromosomes, each pair will have only two chromosomes. Having an extra or missing chromosome usually renders a fetus inviable. In cases where the fetus makes it to term, there are unique clinical features depending on which chromosome is affected. Listed below are some syndromes caused by an abnormal number of chromosomes. A 2. What diagnosis would you give patient A? Diagnosis Chromosomal Abnormality Normal # of chromosomes patient's problems are due to something other than an abnormal number of chromosomes. Klinefelter's Syndrome one or more extra sex chromosomes (i.e., XXY) Down's Syndrome Trisomy 21, extra chromosome 21 Trisomy 13 Syndrome extra chromosome 13

(I)GCSE Topic 3.24 c) Mitosis 3

- DNA Replication occurs during the Interphase

- For a sign that the cell is entering the stages of Mitosis and cell devision is when we see the breakdown of the nuclear membrane = PROPHASE

- Membrane breaks down and the chromosomes are visible as a pair of CHROMATIDS

- Inside the cell, the nucleus is gone and replaced with a network of protein molecules = SPINDLE / SPINDLE FIBERS

- 'Late Prophase' = pair of chromatids move towards the spindle

- METAPHASE = chromosomes are in the middle -arranged across the equator- of the cell 

- ANAPHASE = the spindle fibre shortens, pair of chromatids move apart to the polls of the cell = separation of chromatids

- TELOPHASE = nucleus begins to reform around the chromosomes at either end of the cell

*Not part of Mitosis*

- CYTOKINESIS = the cell splits into two 

= cell bends inwards, dividing cytoplasm in half 

= membrane will fuse across the equator to form the two cells

*2 new cells each contain a new chromosome-same as the parental cell*

(I)GCSE Topic 3.24 b) Mitosis 2

-For cells to be 'identical', the original cell has to copy its chromosomes

- Copying of Chromosomes = DNA Replication

=> each chromosome undergoes a copying process to form an identical copy of itself with the same genes and alleluias 

=> these two copies are held together by a structure around the center region - CENTRONERE

-While the chromosomes are in a copied pair = A Pair of Chromatids

- Process of DNA Replication takes place in the nucleus while the nucleus is still in tact 

=> INTERPHASE of the cell cycle