Zusammenfassung der Ressource
B3
D-F
- D
- In mammals, body
cells are diploid
(two copies of each
chromosomes)
- Most new
body cells are
produced by
mitosis
- Prior to
mitosis DNA
replication
occurs
- Mitosis is needed for
growth, replacement
of cells, repair of
tissues and asexual
reproduction
- Gametes are
produced by
meiosis
- In sexual
reproduction, to
produce a unique
individual, half
the genes come
from each parent
- Gametes are
haploid cells
(contain one
chromosomes of
body cells)
- Gametes have
half the
number of
chromosomes
of body cells
- In sexual
reproduction
gametes join in
fertilisation
- In mitosis the
chromosomes line up
along the centre of the
cell, they then divide and
copies move to opposite
poles of the cell
- DNA replication
involves: 'Unzipping'
the DNA to form single
strands. Forming
double strands form by
complementary base
pairings
- E
- The
ventricles
pump blood
- The left side
pump blood to
the body
- The semilunar,
tricuspid and
bicuspid valves
prevent
backflow
- The right side
of the heart
pumps blood
to the lungs
- Haemoglobin in red
blood cells reacts
with oxygen in the
lungs to
oxyhaemoglobin
- Oxyhaemoglobin
releases oxygen in
tissues to form
haemoglobin
- Blood moves
around the
body in
arteries, veins
and capillaries
- Arteries
transports
blood away
from the heart
- Veins transports
blood to the heart
- Capillaries exchange
materials with
tissues
- Blood in arteries
is under higher
pressure than
blood in veins
- A double circulatory
system is one in
which blood travels
through the heart
twice during on
complete circuit
- F
- Many plants
can grow
continuously
- plants mainly
gain height
through cell
enlargement
- Many plant
ells retain
the ability to
differentiate
- Plant cell
division is mainly
restricted to
areas called
meristems
- Stem cells are
undifferentiated cells
that can develop into
different cells, tissues
and organs
- The process of cells
becoming specialised
is called
differentiation
- Growth is cell division
followed by cells becoming
specialsed
- Wet mass is less accurate
due to the variable water
content
- Growth can be
measured as an
increase in height, wet
mass, or dry mass
- Bacterial cells lack: a 'true'
nucleus, mitochondria and
chloroplasts
- Vacuoles in
plants contain
cell sap and
provides support
- The plant cell wall
is made of cellulose
and provides
support