EXPLAIN THE TERM IN VITRO FERTILISATION 

Involves removing eggs from the ovary and fertilising them outside the body.

 

SUGGEST A REASON FOR THE REMOVAL OF SEVERAL EGGS

A number of eggs are removed to increase the chances of fertilisation occurring and getting an embryo to implant. 

 

IDENTIFY A GERM LAYER FROM WHICH THE SKIN OF THE DEVELOPING  EMBRYO ARISES ? 

Ectoderm 

 

FROM WHICH TISSUES DOES THE PLACENTA FROM 

The placenta is formed from the chorion (the outer membrane of the embryo) and the mother’s blood vessels. 

 

EXPLAIN WHY MIXING MUST NOT OCCUR 

Blood groups may be different types, if their bloods mix, an immune response would be triggered

Mother’s blood pressure may harm the embryo as it is too high.

 

FUNCTIONS OF THE PLACENTA 

The placenta allows substances to be exchanged between mother and embryo, e.g. gases, nutrients, antibodies, etc.  

The placenta also produces progesterone

 

STATE ONE CHANGE THAT OCCURS AND APPROXIMATE DAYS OF THE CYCLE ON WHICH IT OCCURS 

  1. Days 1-5: The endometrium breaks down.   
  2. Day 14: The Graafian follicle bursts releasing the egg from the ovary.

 

WHERE ARE THE HORMONES LH AND FSH PRODUCED 

Pituitary gland 

 

STATE ON ROLE OF EACH 

Role of FSH: It stimulates the egg to develop.

Role of LH: It causes ovulation.

 

NAME 2 OTHER HORMONES 

Progesterone: produced by the corpus luteum ensures the endometrium remains in place (in case the egg is fertilised).

 Oestrogen: Causes growth of the endometrium, stimulates LH

 

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DRAW DIAGRAM OF MALE REPRODUCTIVE SYSTEM 

DRAW X WHERE MEIOSIS OCCURS 

 

SUGGEST WHY SPERM CELL NEED SO MANY MITOCHONDRIA 

Mitochondrion are the site of respiration and so produce energy in respiration. The sperm need a lot of energy to swim to the egg.

 

EXPLAIN WHY MITOCHONDRIA ARE EXCLUSIVELY INHERITED FROM THE MOTHER 

It is just the chromosomes in the nucleus that are inherited from both parents. The cell organelle must come from the egg.

 

STATE SURVIVAL TIMES OF EGG AND SPERM IN THE FEMALE BODY 

Egg 0 - 48 hours 

Sperm 3 days/72hours 

 

GIVE ONE FUNCTION OF A NAMED GLAND

The prostate gland (with the seminal vesicles and Cowper's gland) produces seminal fluid, which provides a medium for sperm to swim and also provides a food source for the sperm.

 

WHAT IT IS THE NEXT DEVELOPMENTAL STAGE AFTER THE MORULA

Blastocyst

 

GIVE ONE CHANGE EXPERIENCED BY THE MOTHER INDICATING THE BIRTH PROCESS IS STARTING 

Contractions/ amnion breaks releasing the amniotic fluid 

 

GIVE A SHORT ACCOUNT OF THE BIRTH PROCESS 

Stage 1

Contractions on the uterus push foetus towards the cervix

Cervix dilates 

amnion break releasing 

Amniotic fluid 

Stage 2 

Foetus passes through the cervix and birth canal head first 

Baby is delivered 

Umbilical cord is tied and cut 

Stage 3 

Uterus contracts again and expels after birth (umbilical cord and placenta)

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NAME THE 3 GERM LAYERS

Ectoderm, mesoderm and endoderm 

 

FOR EACH DERM NAME A STRUCTURE IN THE ADULT BODY THAT DEVELOPS IT

ectoderm- nervous system, mesoderm - skeletal system, endoderm- digestive system 

 

FROM WHAT TISSUES DOES THE EMBRYO DEVELOP 

Embryonic  

 

WHAT IS AN AMNION 

A membrane (sac) that surrounds the embryo

 

EXPLAIN THE IMPORTANCE OF AN AMNION FOR A FOETUS 

Protects the embryo 

 

WHAT IS SEMEN 

Seminal fluid and sperm 

 

NAME A FEMALE MENSTRUAL DISORDER 

Fibroids

Cause: unknown. OEstrogen and progesterone are the hormones produced by the ovaries. They cause the uterine lining to regenerate during each menstrual cycle and may stimulate the growth of fibroids

Treatment: radiation or surgically removed 

 

MORULA: Solid ball of cells

 

BLASTOCYST: Fluid filled or hollow ball of cells 

 

2 BIOLOGICAL ADVANTAGES OF BREASTFEEDING 

Ideal balance of nutrients for baby 

Contains essential antibodies protecting the baby against infection