National Biology
Reproduction summary
Reproduction is the production of new members of a species:
It can be _______ - which requires sex cells
or _________
- which doesn’t require sex cells
All cells have two sets of ____________. If a cell has a single set of chromosomes it is said to be a ________
cell. If it has two sets of chromosomes it is said to be __________ . Haploid cells are formed by a type of
cell division called ___________. When two haploid sex cells (sperm/egg) join during the process of
fertilisation, the new diploid cell formed is called a ________.
In flowering plants, the male sex cells are found inside
_________ grains. These are found inside the ________.
The female sex cells are found inside the ___________.
_____________ is the transfer of pollen from one flower
to another. This can be done by __________ or by the
______. During this process pollen is transferred on to the
top of the __________.
After pollination, the pollen grains have to travel down the
style and by developing a _________ ________. Once the
male and sex cells meet, they combine together – this is known as ______________.
Plants can also undergo asexual reproduction. This doesn’t involve sex cells, or require the process of
fertilisation. All the offspring produced this way are genetically _________ to their parent plant.
Strawberry plants can reproduce asexually
using runners. ________ and ________ plants
can also reproduce asexually, using
underground bulbs or tubers.
Asexual reproduction has the benefit of not requiring pollination or fertilisation. However, sexual
reproduction has the advantage of ensuring a mixture of characteristics in each new plant – this leads to
___________.
Anther
asexual
chromosomes
haploid
meiosis
onion
ovary
pollination
potato
sexual
stigma
identical
style
nectary
wind
diploid
pollen
wind
petal
fertilisation
pollen tube
variation
zygote
filament
insects
In mammals the sex cells are the________ from the male, and the ______ from the females. The sperm are
produced in the ________, and the egg cells are formed in the ________. The __________ of the male
deposits sperm inside the ________ of the female.
Fertilisation occurs when the sperm and egg join together – this
occurs in the ________ of the female.
After the zygote has been formed, it develops into a ball of cells
called a __________ which is implanted into the wall of the
__________.
After a few weeks the __________ will form, which supplies the foetus with it’s nutrition. The developing
foetus is connected to this via the _________ _______.
Through the placenta, the foetus is supplied with _______ and ________
from the ___________ blood supply.
The placenta will also remove _________ and _______ _________ from the
foetus’ blood supply.
In many animals, fertilisation occurs ___________ - outside the female body
(e.g. fish and _________). This requires a very ________ number of eggs to be produced, as the chances of
fertilisation being successful are very ____. Other animals reproduce __________ - inside the female body
(e.g. birds and _________). Chances of success are higher, therefore the number of eggs produced is
relatively ______.
_________ ________ defines how much attention a parent gives to the offspring. In ______ this is virtually
none. Their offspring will initially survive by feeding on a ______ sac, until they are able to feed for
themselves.
In mammals parental care is very ______ . Young offspring will obtain food by _______ milk from their
mother.
In animals asexual reproduction is very rare. It normally only occurs in ______ _________ e.g. bacteria
reproducing by __________.
Amphibians
externally
high
micro-organisms
parental care
testes
zygote
parental care
fertilisation
internally
milk
penis
umbilical cord
blastocyst
foetus
large
mother’s
placenta
uterus
carbon dioxide
egg
food
fish
low
mammals
ovaries
oviduct
sexual
sperm
vagina
waste
fission
oxygen
suckling
yolk