Unit 16: Human Reproductive System Flashcards
Sexual Reproduction
4pt
- Requires two parents, a male and a female, and involves special cells called gametes (sex cells)
- Occurs in multicellular organisms
- The new organisms are not identical to the parents
- inherit characteristics from both parents
Asexual Reproduction
4pt
- Production of new organisms from a single parent
- Usually occurs in unicellular organisms such as the amoeba
- New cells identical to the parent
- A single amoeba reproduces itself by dividing into two new cells (division)
what is puberty
3pt
- Puberty is a period where the body undergoes various physical changes and matures sexually
- Puberty is necessary for the human body to prepare itself for sexual reproduction
- Puberty begins when sex hormones are produced in the reproductive organs
- eg oestrogen in ovaries and testosterone in testis
Physical Changes during Puberty
Changes in Female only
4pt
Ovaries release Ova (Egg)
Menstruation Begins
Breasts begins to develop
Hips become broader and rounder
Physical Changes during Puberty
Changes in both Male and Female
4pt
Sex Hormones released
Hair grows in armpits and around reproductive organs
Sex organs become larger
Height and weight increase
Physical Changes during Puberty
Changes in Male only
4pt
Testis produce Sperms
Voice Deepens
Hair grows on face and body
Muscle strength increase
Sex Glands
3pt
- Produce fluids in which the sperms swim in
- The mixture of sperms and fluid is called semen
- Semen contains nutrients and lubricating effect to help the sperm move better
Scrotum
2pt
- A bag of skin which holds the testes outside the body
- The testes are outside the body because it requires a lower body temperature to produce healthy sperms (enrichment)
Testis (plural: Testes)
3pt
- The testes produce male sex cells called sperms.
- Each sperm is very small and shaped like a tadpole.
- The sperm is the smallest cell in the human body
Sperm Duct
1pt
- Carries sperms from the testis to the penis
Urethra
1pt
- A tube which carries sperms and urine at different times
Penis
1pt
- The organ from which sperm-carrying fluid leaves the body and is deposited in the body of the female
Ovary (Plural: Ovaries)
4pt
- The ovaries produce eggs or ova (singular: ovum).
- Normally, one ovum is produced (released) each month.
- The ovum is the female sex cell.
- It is the largest cell in the human body (and is the size of this full stop).
Oviduct (fallopian tube)
2pt
- A tube which carries ova released from the ovary to the uterus
- It waits for the sperm to reach for a few days before getting passed out of the system
Uterus
1pt
- A pear-shaped structure where an embryo grows and develops
Cervix
1pt
- The narrow opening of the uterus; it widens during the birth of a baby
Vagina
2pt
- A tube which links the uterus to the outside of the body
- Organ in which sperms are deposited and the passage though which a baby is born
Uterine Lining
1pt
- To provide nutrients to embryo if fertilised or sheds if egg is unfertilised and repairs itself every menstrual cycle
Human Sexual Reproduction
3pt
- The fusion of sex cells is called fertilization
- 3 stages in human reproduction on how life is formed: Fertilisation, Pregnancy, Birth
- Nucleus of the cell contains the genetic information (DNA) in chromosomes
Sperm
Movement ability
Location of Nucleus
No. of Chromosomes
No. of cells
Can move on its own with the help of the tail
Nucleus located in the head segment
Nucleus containing 23 chromosomes
About 2 million of sperms per ejaculation
Egg (Ovum)
Movement ability
Location of Nucleus
No. of Chromosomes
No. of cells
Cannot move on its own
Nucleus located in the cell
Nucleus containing 23 chromosomes
Only one egg released in every 28-day cycle
Heredity
6pt
- The process of passing down the genetic material from one generation to the next during sexual reproduction is called heredity
- The nucleus in each human cell contains 46 chromosomes (23 pairs)
- The chromosomes carry genes containing information that controls the growth and appearance of a child
- Unlike ordinary cells, the ovum and the sperm have 23 single chromosomes each
- During fertilisation, the 23 single chromosomes in each nucleus come together to form 23 pairs of chromosomes
- Thus, a child receives half its genetic information from the mother (through the ovum) and half from the father (through the sperm)
Menstrual Cycle
Day
1 to 5
Events
4pt
- The thickened lining of the uterus is shed if fertilisation does not take place
- It is discharged through the vagina together with blood
- Menstruation occurs
- Unfertilised egg, uterine lining and blood is discharged
Menstrual Cycle
Day 6 to 9
Events
2pt
- The lining on the wall of the uterus thickens with many blood vessels formed in it.
- This process prepares the uterus for the implantation of the embryo if fertilisation occurs