Answer four questions only
Question (1)
A- Choose the correct answer
1- The points of connection of internal chromatids in homologous chromosomes pairs is called ……….
A- Chiasma B- Chromosome C- Centromere D- Centrosome
2- In gametes, chromosomes which didn't undergo crossing over are called ….
A- New chromosomes B- Building chromosomes C- Parental chromosomes
D- Chromatids
3- When a sound male and a female infected with colour blindness marry, the appearance of this case will be in …………..
A- All males B- All females C- Half the males D- Half the females
4- Blood group which is know as "Universal donor" is……
A- A B- O C- AB D- B
5- Trait of flower colour of sweet pea plant is an example on ……….
A- Lack of dominance B- Alleles multiplicity C- Complementary genes
D- Lethal genes
B- Give reasons for
1- Turner's syndrome affects females only
2- The importance of blood groups
3- The importance of crossing over phenomenon
4- Colour blindness is more common in males than females
Question (2)
A- Write the scientific term
1- Genes which interact with each other causing the appearance of a hereditary trait.
2- A form of inheritance in which no genes dominate over the opposite one, but they interact forming new trait
3- chemical substances which exist on the surfaces of red blood cells, they play an important role in blood transfusion process.
4- Genetic disorder caused by the decrease of chromosome (X) in some females (XO+44)
5- Genetic disorder caused by the existence of an additional chromosome in chromosome pair (21)
B- What happens when
1- Breeding two yellow mice (Yy)
2- A sperm (Y+22) fertilizes an abnormal ovum (XX+22)
3- Two sweet pea plants with white flowers whose genotypes are (aaBB) and (AAbb) copulate (first and second generations)
4- Transfusing blood from a man of group (AB) to another one of group (A)
Question (3)
A- Match
-
(B)
(A)
A- Lack of dominance
1- Flower colour of sweet pea plant
B- Lethal genes
2- Colour blindness in human
C- Complementary genes
3- Yellow colour of mice
D- Sex-linked traits
4- Flower colour of four o'clock plant
E- Sex-influenced traits
5- Milk production in females
F- Sex-limited traits
B- Write short notes about
1- Chromosomal theory
2- Rhesus factor
3- Pedigree
4- Sex-limited traits
Question (4)
A- Correct the underlined words
1- The genetic disorder caused by extra (X) sex chromosome in males is Down syndrome
2- DNA fingerprint was discovered by Thomas Morgan
3- Hemophilia is an example on sex-influenced traits
4- The appearance of chlorophyll is affected by the factor of temperature
5- The ratio of 2nd generation in case of complementary genes is 1:3:3:9
B- Compare between
1- Blood types (A) and (B)
2- Lethal and complementary genes
3- Klinefelter's and Turner's syndrome
4- Antigens a and anti-a
Question (5)
A- The following figure describes the pedigree chart for the trait of freckles presence , answer the questions
1- Is this trait dominant or recessive? Why?
2- What are the probable genotypes of individuals (1), (2), (6), (7), (9)
Question (1)
A- Choose the correct answer
1- Chiasma
2- Parental chromosomes
3- All males
4- O
5- Complementary genes
B- Give reasons for
1- Because Turner's syndrome is caused when an abnormal ovum with no X chromosomes (O+22) is fertilized by a sperm (X+22), which forms a female zygote of Karyotype (XX+44).
2- Because they :-
- Solve problems of the determination of paternity (parents of children) and pedigree of children (blood groups denies pedigree but don't prove it)
- Determine blood transfusion processes between individuals.
- Are used in the study of human races classification and evolution
3- Because it causes the variation of hereditary traits of the members of same species, which helps them in the adaptation with environment conditions, and the development and continuation of their life.
4- Because colour blindness trait gene is carried on one (X) sex chromosome in males, while it has two genes carried on (XX) sex chromosomes in females. so colour blindness is more common in men because they should have only one recessive gene to be infected with colour blindness .
Question (2)
A- Write the scientific term
1- Complementary genes
2- Lack of dominance
3- Antigens
4- Turner's syndrome
5- Down syndrome
B- What happens when
1- H ybrid yellow and black mice are produced at ratio 2:1 respectively, pure yellow mice (YY) - which represent 25% of the generation – die in uterus before being born.
2- This causes Klinefelter's syndrome, which affects males and make them infertile.
3- 100% pink flowers are produced in the first generation, while both pink and white flower appear in the second generation at ratio 9:7
4- This will break red blood cells of the recipient person because his blood produces anti-b for antigens-B of blood group (AB), which causes shivering in body, chest pain, blueness, irregular heartbeat, headache, low blood pressure
Question (3)
A- Match
1- C 2- D 3-B 4-A 5-F
B- Write short notes about
1- Scientists Boveri and Sutton put chromosome theory in 1902, which states that:-
- Chromosomes exist in somatic cells in the form of homologous pairs (2n)1
2- Gametes contain half the no. of chromosomes in somatic cells as a result of meiotic cell division; where homologous pairs get separated from each other forming two identical groups
3- Each pair of chromosomes acts independently when transferring to gametes.
4- After fertilization process, the normal number of chromosomes (2n) comes back
5- Each chromosome carries hundreds of genes.
2- Rhesus factor is a kind of antigens which exist on the surfaces of red blood cells of 85% of humans, its inheritance is controlled by 3 pairs of genes which exist on one chromosome pair.
3- Hereditary data represented in the form of chart diagram which explains how a certain trait is inherited, and used in tracing different hereditary traits
4- They are traits which appear in only one of the two sexes due to the difference of hormones, such as the growth of beard trait in men and milk production trait in women.
Question (4)
A- Correct the underlined words
1- Klinefelter's syndrome
2- Dr. Alec Jeffreys
3- Milk production trait in women
4- Light
5- 7:9
B- Compare between
Blood group (B) |
Blood group (A) |
- It has antigens-b - It has antibodies (anti-b) - Its genotype if BB or BO - Receives blood from groups (B), (O) - Gives blood to groups (B), (AB) |
- It has antigens-a - It has antibodies (anti-b) - Its genotype is AA or AO - Receives blood from groups (A), (O) - Gives blood to groups (A) and (AB) |
Complementary genes |
Lethal genes |
- They are genes which interact together forming new trait
Ex. Flower colour of sweet pea plant |
- They are genes which cause the death of living organisms if they are present in pure form because they stop its biological processes
Ex. Yellow colour of mice trait |
Turner's syndrome |
Klinefelter's syndrome |
- Its karyotype is (XO+44) - Caused due to the fertilization of an abnormal ovum (O+22) by a sperm (X+22) - If affects Females only - It causes inability to attain puberty |
- Its karyotype is (XXY+44) - Caused due to the fertilization of an abnormal ovum (XX+22) by a sperm (Y+22) - If affects males only - It causes infertility, tall stature, ..etc |
Antibodies-a |
Antigens-a |
They exist in blood groups (B) and (O) |
They exist in blood groups (A) and (AB) |
Question (5)
A- The following figure describes the pedigree chart for the trait of freckles presence , answer the questions
1- This trait is recessive because it disappeared in all members of 1st generation
2-
(1) AA
(2) aa
(6) Aa
(7) Aa
(9) aa