CIE A LEVEL BIOLOGY
Jia Xuan
by
,CHROMOSOMES
KEY TERMS
Homologous chromosomes → chromosomes with .
same size I length
• same shape
.
same banding pattern
• same order of loci
→ chromosomes up in prophase I
pair
ftp.oioi
t
Sexual reproduction
g
I. ad !!!
" 's
"" "
which contains only one set of
Chromosomes
✓
.
9mYYotYg Diploid ( 2n )
Lr> which
\ ¥
A cell contains two sets of
"
chromosomes .
2n
Fertilisation
GAMETOGENESIS
Gametogenesis of
→
production gametes
Tex cells for fertilisation
✓ production of
in humans eggs
-
/ production of sperm
Gametogenesis
\ in plants -
- production of
pollen grains
production of
embryo sac
, HUMANS
IN OOGENESIS LIM
1
oogenesis → The
production of eggs Ova in the ovaries
MITOSIS diploid
I t
I
" ro :
Yff I 1
)
GROWTH
MEIOSIS
V
diploid
primary oocyte
(
produced in
embryo )
#p -
v v
Secondary oocyte ⑧ haploid
( after puberty) polar body
#p v
secondary oocyte
( once a month )
\!
" "" """ °"
polar body
✓
ovum
haploid