B15.4 - Sexual reproduction in humans Flashcards
What is the function of the testes? [1]
produces sperm
What is the function of the scrotum? [2]
- holds the testes outside the body
- at the ideal temperature for the formation of sperm
What is the function of the sperm ducts? [1]
muscular tube that carries sperm from the testis to the urethra
What is the function of the prostate gland? [1]
gland that produces the liquid that gets added to the sperm to make semen
What is the function of the urethra? [1]
tube which carries sperm through the penis during ejaculation
What is the function of the penis? [2]
- swells when filled with blood
- for introducing sperm into the vagina of the female
What is the function of the ovaries? [2]
- organ that produces the eggs
- and the sex hormones oestrogen and progesterone
What is the function of the oviducts? [2]
- muscular tube that carries the egg from the ovary to the uterus
- fertilisation happens here
What is the function of the uterus? [1]
organ where the embryo grows
What is the function of the cervix? [2]
- ring of muscle at the neck of the uterus
- holds the baby in place during pregnancy
What is the function of the vagina? [3]
- muscular tube connecting the uterus to the outside
- penis is inserted here during intercourse
- menstrual blood and the baby both leave the body this way
What is the function of the uterus lining? [2]
- fertilised egg implants in to this
- if not pregnant - this is shed each month as a period
What is fertilisation? [2]
the fusion of the nuclei from the male and female gametes
What are the effects of oestrogen? [4]
- breasts develop
- body hair grows
- menstrual cycle begins
- hips get wider
What are the effects of testosterone? [5]
- growth of penis and testes
- growth of facial and body hair
- muscles develop
- voice breaks
- testes start to produce sperm
What is oestrogen? [2]
- sex hormone
- in GIRLS
What is testosterone? [2]
- sex hormone
- in BOYS
What are changes that occur to both boys and girls during puberty? [4]
- growth of sexual organs
- growth of body hair
- more interest in sex
- increased mood swings
What is ovulation? [2]
- on the 14th day
- the egg is released
What happens to the lining of the uterus each month? [1]
it thickens to prepare for a fertilised egg
What happens to the egg at the same time the uterus lining thickens? [1]
the egg starts to mature in one of the ovaries
What happens to the uterus lining after ovulation if the egg is fertilised? [2]
- egg may implant in the uterus lining
- where it is protected and receives nutrients and oxygen from the mother
What happens if the egg is not fertilised? [2]
- the uterus lining breaks down
- both the egg and the lining are removed from the body during menstruation
What is menstruation? [2]
the shedding of the uterus lining and egg when the egg is not fertilised
What are the hormones involved in the menstrual cycle? [2]
- oestrogen
- progesterone
What is oestrogen during the menstrual cycle? [2]
- repairs/builds up the lining
- secreted from the ovary
What is progesterone during the menstrual cycle? [2]
- maintains the uterus lining
- secreted from the ovary
What are the adaptations of a sperm cell and their description? [6]
- flagellum = allows the sperm to swim towards the egg
- contains many mitochondria = to provide energy for the movement of the flagellum
- presence of enzymes = contains enzymes in the head to digest a route into the egg for fertilisation
What are the adaptations of an egg cell and their description? [4]
- cytoplasm contains a store of energy = provides energy for mitosis in the developing zygote
- jelly-coat changes at fertilisation to prevent more than one sperm from entering
What is the size of a sperm and egg cell? [2]
- sperm: very small (0.045mm)
- egg: large (0.15mm)
What is the structure of a sperm and egg cell? [4]
- sperm: head region, flagellum, mid section containing mitochondria
- egg: round cell covered in a jelly-coating and lots of cytoplasm
What is the motility in a sperm and egg cell? [2]
- sperm: capable of locomotion
- egg: not capable of locomotion
