definition/functions biology

pollination

the transfer of a pollen grain from a mature anther to a stigma

self-pollination

the transfer of a pollen grain from a mature anther of a flower to the stigma of the SAME flower or different flower of the SAME plant

cross-pollination

the transfer of a pollen grain from a mature anther of a flower to the stigma of a DIFFERENT plant of the same species

sepal

encloses and protects the petals and the reproductive organs during the bud stage

petals

brightly coloured and provides as a landing platform for insects in insect pollinated flowers

filament

phloem transports sucrose and amino acids to anther while xylem transports water and mineral salts to anther

anther

produces pollen grains and the mature anther splits open to release the pollen grain

pollen grain

contains male gamete for reproduction

stigma

receives the pollen grain and secretes sugary fluid that stimulates the pollen grain to germinate

style

holds stigma in a suitable position to receive pollen grain

ovary

contains ovum that has female nucleus for reproduction

asexual reproduction

the process resulting in production genetically identical offspring from 1 parent plant

sexual reproduction

the process involving the fusion of nucleus of male and female gametes to form a zygote and the production of genetically dissimilar offspring

mitosis

type of cell division giving rise to genetically identical cells in which chromosome number is maintained

meiosis

type of cell division giving rise to genetically dissimilar cells in which chromosome number is halved due to separation of homologous chromosome

mitosis importance

ensures the growth of new cells, repairs worn out cells, for asexual reproduction producing genetically identical cells

meiosis importance

produces gametes for fertilisation in sexual reproduction, allows for genetic variation in species

testes

produces sperms for reproduction and male sex hormones (testerone)

scrotum

provides an optimum temperature for the development of sperms

epididymis

stores immature sperms and site of maturation of sperms

sperm duct

conducts sperms from testes to urethra

prostate gland

produces seminal fluid which contains enzymes and nutrients to nourish sperms and activate them

urethra

conducts urine and semen to outside of the body

penis

deposits semen containing sperms into vagina during sex

ovary

produces egg cells and releases mature eggs, produces female sex hormones

oviduct

conducts mature egg cells from ovary to uterus, site of fertilisation

uterus

provides a suitable environment for development of foetus and provide it with nutrients during pregnancy, elastic muscular walls that contract to expel foetus during birth

uterine lining

site of implantation of embryo, forms part of mothers placenta

cervix

keeps the opening of the uterus closed during pregnancy, dialates during birth to allow foetus to exit uterus

vagina

receives semen containing sperms and allows discharge of blood during menstruation, provides passageway for birth

menstruation

the breakdown of the uterine lining which is discharged as blood through the vagina

ovulation

the day where the ovary releases a mature ovum into the oviduct

rbc

transports oxygen in the form of oxyhaemoglobin from lungs to respiring parts of the body via heart

plasma

transports substances

wbc

protect and defend the body against pathogens

platlets

initiates blood clotting process under injury which prevents excessive blood loss and entry of bacteria into the blood

coronary heart arteries

transports oxygenated blood from aorta to heart muscles so ensure they can contract and relax

gene

a short segment of DNA molecule which contains information for the synthesis of 1 specific polypeptide

chromatin

threadlike structure which consists DNA molecule coiled around histone proteins

chromosome

compact and condensed structure which contains DNA molcule