79859310 chapter 3 heredity and variation
TRANSCRIPT
-
8/12/2019 79859310 Chapter 3 Heredity and Variation
1/14
Name: Class: .Chapter 3Exercise 1Learning Area: Heredity and VariationLearning O!ecti"e: #nderstanding cell di"ision
1. $he diagram elo% sho%s the process o& mitosis. 'ill in the lan(s %ith the %ords gi"en.
)eplication align n*cle*s memrane di"ide t%oshorten thic(en Chromatid same separate mo"e
Stages of mitosis Simple explanation
+ Chromosomes in the n*cle*s . ,
and are more "isile.
+ o& chromosomes occ*r.
+ Each strand o& chromosome is called a .
+ Chromosomes ......................... themsel"es in the centre o&the cell.
+ $he .. disappears.
+ Chromatids and to the opposite ends o& the cell.+ At the same time, the cell starts to ..
+ $he n*cle*s memrane &orms again.+ da*ghter cells are &ormed.+ Each progeny cell has the . n*mer o&chromosomes as the parent cell.
3-1
-
8/12/2019 79859310 Chapter 3 Heredity and Variation
2/14
-. Arrange the diagram in the correct se*ence:
3-2
P Q R
W X
S
T U V
-
8/12/2019 79859310 Chapter 3 Heredity and Variation
3/14
Name: Class: .Chapter 3Exercise -Learning Area: Heredity and VariationLearning O!ecti"e: #nderstanding cell di"ision
1. $ic( /0 &or the correct statement and /2 &or the %rong statements ao*t mitosis.
/i $%o da*ghter cells are &ormed in mitosis. / /ii n mitosis, cytoplasm di"ides once. /
/iii 4itosis is important &or prod*cing ne% cells to replace the old or damaged cells. /
/i" 4itosis ca*se genetic "ariation. /
/" $he n*mer o& chromosomes in the da*ghter cell is hal& the n*mer o& chromosomes inthe parent cell. /
/"i $he parent cell and the da*ghter cell ha"e the same genetic content. /
/"ii Crossing5o"er does not ta(e place in mitosis. /
/"iii 4itosis occ*rs in somatic cells. /
-. $ic( /0 &or the correct statement and /2 &or the %rong statements ao*t meiosis.
/i 'o*r da*ghter cells are &ormed in meiosis. /
/ii n meiosis, the n*mer o& chromosomes in each da*ghter cell is the same as in the parentcell. /
/iii 4eiosis is important to organisms that reprod*ce sex*ally eca*se it prod*ces gametes. /
/i" 4eiosis ca*se genetic "ariation. /
3-3
Score: ./27 x 100 = %
-
8/12/2019 79859310 Chapter 3 Heredity and Variation
4/14
3. Compare the processes o& meiosis and mitosis.
3-4
MEIOSIS MITOSIS
SIMILAI!I"S
/i../ii../iii..
#I$$"
"&"S
..
N*mer o&di"isions .
..
N*mer o& da*ghtercells prod*ced ..
..
N*mer o&chromosomes in
da*ghter cell comparedto parent cell
.
.
Comination o&chromosomes in
da*ghter cell comparedto parent cell
..
.
Crossingo"er ..
..
6enetic"ariation ..
-
8/12/2019 79859310 Chapter 3 Heredity and Variation
5/14
Name: Class: ..Chapter 3Exercise 3Learning Area: Heredity and VariationLearning O!ecti"e: #nderstanding the principles and mechanism o& inheritance.
1. Complete the tale %ith the correct de&inition.
!"MS #"$II!I'S
7escries the characteristics traits o& an organism, incl*ding thephysical and the physiological
Organism %hich has t%o identical genes. Example: $$ or tt.
Composition o& gene in an organism
. $hread5li(e str*ct*re present in the n*cle*s o& a cell
..A gene %hich is %ea( and its e&&ect can e mas(ed y adominant gene
.An organism %hich has one dominant gene and one recessi"egene &or a certain characteristic. Example: 8 / 8 9 dominant gene&or lac( &*r , 9 recessi"e gene &or %hite &*r
#nit carrying a characteristic trait %hich exists in pairs in a
chromosome.
.Organism %hich has t%o di&&erent memers o& the same gene.Example: $t.
.Exchange o& genes %hen t%o chromatids cross gi"ing rise togenetic "ariation.
.. A gene %hich mas(s the e&&ect o& a %ea(er gene
3-5
henotype Chromosomes Crossing o"er 7ominant gene 6ene 6enotype Hetero;ygote Homo;ygote Hyrid )ecessi"e gene
Score: ./2( x 100 = %
-
8/12/2019 79859310 Chapter 3 Heredity and Variation
6/14
-. A man %ith lac( hair /8 marries a %oman %ith londe hair /.Complete a schematic diagram to sho% the cross et%een a men %ho is hetero;ygo*s &or lac( hair
/8 and a %oman %ith londe hair /
8 : 6ene carrying lac( hair trait /dominant : 6ene carrying londe hair trait /recessi"e
'ather 4otherarent
4eiosis
6amete
'ertilisation
O&&spring genotype
O&&spring phenotype
3-6
8
-
8/12/2019 79859310 Chapter 3 Heredity and Variation
7/14
8ased on the schematic diagram, determine the phenotype ratio o& their o&&spring
.
Name: . Class: Chapter 3Exercise