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reproduction in humans (isabelle) - Coggle Diagram
reproduction in humans (isabelle)
reproduction
definition
production of new organisms
importance
continuation life of living organism > producing offspring
types
sexual
two gametes(sex cells) fusing together forming fertilised egg (zygote)
example
male gamete + female gamete fusing, forming zygote. e.g. fertilisation (human).
asexual
does not involve fusion of gametes.
example
fission
cell divides > two identical 'daughter cells'. e.g. bacteria + fungi.
budding
cell splits producing 'mother' cell (1)+ 'daughter' cell (2) . (1) is larger than (2).
e.g. yeast
comparison
sperm
head, middle piece, tail
move on its own with tail
nucleus in the head
23 chromosomes, small
released in millions in each ejaculation
egg
spherical cell
cannot move on its own
nucleus in the cell
23 chromosomes, big
released one in each month
male reproduction system
functions
discharge sperms to female reproductive system
produce + secrete male sex hormones called testosterone
produce, store + transport sperms
parts
seminal vesicles
produce seminal fluid (semen) mixed with sperms
produce thick + white fluid (semen + sperms)
provides nutrients + lubricates sperms facilitate movement.
vas deferens
carries sperms from testes to urethra
uretha
carries urine + semen to outside of body
epididymis
stores sperms temporarily
penis
deposits semen with sperms into vagina during sexual intercourse
testis (testes)
produces sperms + male hormones (testosterone)
scrotum
holds testes outside of body
loose sac holds testes, maintain below body temperature > sperms develop better.
female reproductive system
functions
produce mature eggs for reproduction
produce female sex hormones (oestrogen + progesterone)
parts
uterus
allows implantation of embryo for growth + development
cervix
narrow opening, widens during childbirth
fallopian tubes
allows fertilisation to take place
vagina
muscular organ sperms are deposited
ovary
produces mature eggs/ova (S: ovum) + female sex hormones
estimated 300-400 thousand eggs during puberty.
eggs mature > start of menstruation (rate of about one egg/per month)
others
puberty
definition
period of human growth + development (boy + girl physically mature)
facts
body change from child to adult.
sex organs fully functional + produce mature gametes.
girls
age: 10-12
oestrogen + progesterone
common changes during puberty caused by sex hormones
production mature eggs/ovulation starts
breasts enlarge + hips broaden
pubic hair growth + armpit hair
growth spurt (grow suddenly)
onset of menstruation
sperm production
penis + testes increase size
voice deepens
4.pubic hair growth + armpit hair
growth spurt (grow suddenly)
boys
age: 12-14
testosterone
fertilisation
definition
fusion of nuclei of sperm + egg form fertilised egg/zygote.
facts
stages
stage 2
sexual intercourse, semen millions sperms discharged in vagina
sperms swim towards fallopian tube from vagina meet mature egg
egg is surrounded million sperms. ONLY 1 penetrate egg, fertilising it
fertilised egg (zygote), nucleus contains 23 pairs of chromosomes after fusion
both nuclei from male + female gametes.
stage 3
zygote move to uterus with tiny hairs of fallopian tubes
zygote divide into ball of cells (embryo)
stage 1
mature egg release from one of ovaries > fallopian tube (ovulation)
stage 4
embryo reach uterus (7 days). embryo embeds itself into uterine wall (implantation)
blood vessels in uterine lining provide nutrients for embryo develop
few months, embryo grows into foetus (unborn baby)
characteristic
fusion passes certain characteristics of parents to offspring using genes.
genes - special carriers human traits, inherit certain characteristics from parents (hereditary)
placenta
definition
connects developing foetus to uterine wall through umbilical cord.
functions
deliver nutrients + oxygen to foetus
remove waste substances + carbon dioxide from baby
mother's blood + baby's blood do NOT mix in placenta
menstrual cycle