Reproduction in Humans Flashcards
what does asexual reproduction involve
only one individual (identical offspring)
what does sexual reproduction involve
two gametes from different parents, later fuse to form a zygote, genetically unique individual –> undergoes cell division and develops into an embryo
when do sex organs in humans begin to mature and become active
puberty
where does the male reproductive system produce sperm
testes
where do the sperm travel from male testes and how do they make semen
to the penis in the sperm duct, with secretions from the seminal vesicle and the prostate gland making semen
where does the female reproductive system release mature ova from developing follicles in the menstrual cycle
ovaries
what is the point of fertilisation/conception
when one sperm penetrates the ovum in the fallopian tubes
how long does it take for the fertilised ovum to grow and mature into a fully developed foetus ready for birth
40 weeks (9 months)
does asexual reproduction involve mitosis
yes
does the number of chromosomes in the cells remain the same in asexual reproduction
yes, producing many identical offspring
what happens to organisms if the environment changes that have been asexually reproduced
the lack of variety in their genetic make-up will mean that they are unlikely to survive
does sexual reproduction involve meiosis
yes
in sexual reproduction does the number of chromosomes halved when the gametes are formed
yes
offspring formed from sexual reproduction contains a mixture of what
genetic information from both different parents –> genetic variety comes from this
what takes place on a male during puberty
- growth of penis + testes
- growth of facial + body hair
- muscle development
- voice breaking
- sperm production starts
- increase body mass
- increased sexual drive
what hormones control male puberty
FSH, LH, testosterone
FSH stimulates … while LH stimulates the testes to produce the male … testosterone causes the development of the male secondary …
sperm production
sex hormone testosterone
sexual characteristics
what takes place on a female during puberty
- development of breasts
- development of body hair
- beginning of the menstrual cycle (period)
- development and growth of sexual organs
- increased body mass (hips)
- voice depends without ‘breaking’
- increased sexual drive
what hormones control female puberty
FSH, LH, oestrogen, progesterone
FSH and LH are released by the … FSH stimulates the development of … in the ovaries. they also interacts with the female sex hormones …
pituitary gland
mature ova
oestrogen and progesterone
what happens when the sperm has reached the ovum
its nucleus must enter the ovum and fuse with the ovum nucleus, once the sperm has broken through the membrane of the egg, to ensure no more sperm get in an extra membrane (fertilisation membrane) quickly forms which is extra strong
what is a zygote
something made up of two gametes, formed by fertilisation and has a full number of chromosomes (46)
after the zygote is formed how to does it divide and multiply to create a foetus
via mitosis, but certain cells become specialised in order to avoid a mass ball of cells
once the zygote has begun to develop into an embryo and implanted itself into the lining of the uterus what will it start to develop
a placenta
what does the placenta on an embryo do
allows it to obtain materials such as oxygen and nutrients from the mothers blood and discharge materials such as urea and carbon dioxide
what does the embryo secrete to maintain the pregnancy and sport it aborting itself
female hormones especially progesterone
what encloses the developing embryo in the uterus to protect it from knocks and bumps
amnion which secretes a fluid called amniotic fluid
