1.
(A) and (B) are two different types of sex chromosomes where (A) chromosomes were found in a single form in a rooster somatic cell while the contrary occurs in hen where they are present as a pair , the chromosome which determines the sex in the upcoming chicken in order to be a rooster is:
Correct Answer
A. B
Explanation
In chickens, the sex is determined by the presence of sex chromosomes. The male chicken, or rooster, has two different types of sex chromosomes, denoted as (A) and (B). In a rooster somatic cell, (A) chromosomes are found in a single form, indicating that the rooster carries only one copy of the (A) chromosome. On the other hand, in hens, the (A) and (B) chromosomes are present as a pair, indicating that hens have two copies of both the (A) and (B) chromosomes. Therefore, in order for a chicken to develop into a rooster, it must have the (B) chromosome, making (B) the correct answer.
2.
Huntington's disease is a rare, inherited disease that causes the progressive breakdown (degeneration) of nerve cells in the brain .Huntington's disease is an autosomal dominant genetic disorder. Huntington's disease has a broad impact on a person's functional abilities and usually results in movement, thinking (cognitive) and psychiatric disorders. Huntington's disease has a broad impact on a person's functional abilities and usually results in movement, thinking (cognitive) and psychiatric disorders.
Huntington's disease symptoms can develop at any time, but they often first appear when people are in their 30s or 40s. If the condition develops before age 20, it's called juvenile Huntington's disease. When Huntington's develops early, symptoms are somewhat different and the disease may progress faster. The probability percentage of the disease inheritance in the offspring knowing that one partner carries the disease is:
Correct Answer
C. 50 % to 100%
Explanation
Huntington's disease is an autosomal dominant genetic disorder, which means that if one parent carries the disease, there is a 50% chance that their offspring will inherit the disease. However, it is also possible for the offspring to inherit the disease with a probability greater than 50%. This is because the inheritance pattern of Huntington's disease is not strictly predictable and can vary. Therefore, the probability of disease inheritance in the offspring of a parent with Huntington's disease can range from 50% to 100%.
3.
Cystic fibrosis is an example of a recessive disease. Cystic fibrosis is a hereditary disease that affects the lungs and digestive system. The body produces thick and sticky mucus that can clog the lungs and obstruct the pancreas. Cystic fibrosis (CF) can be life-threatening, and people with the condition tend to have a shorter-than-normal life span. Ahmed was a disease carrier and his wife Mona was disease - free , without any genetics examinations carried a doctor confirmed that their offspring will be healthy and free from that disease?
In your opinion the doctor was:
Correct Answer
C. Not true nor wrong
Explanation
The doctor's statement cannot be determined as true or false based on the information given. While it is true that Ahmed is a disease carrier and Mona is disease-free, this does not guarantee that their offspring will be healthy and free from the disease. There is still a possibility that their child could inherit the recessive gene for cystic fibrosis from Ahmed and develop the disease. Therefore, the doctor's statement is not definitive and cannot be considered true or false.
4.
Nader has black curly hair ... he married Nesreen with light straight hair.
The percentage of having a female baby with the same characters as her mother is:
Correct Answer
D. 3.12%
Explanation
When Nader has black curly hair and Nesreen has light straight hair, it indicates that both parents have different hair characteristics. The given percentage of 3.12% suggests that there is a very low probability of having a female baby with the exact same hair characteristics as her mother. This is because the baby could inherit either the black curly hair from the father or the light straight hair from the mother, resulting in a mix of characteristics.
5.
Abdullah and Shaimaa were married . Abdullah has brown eyes while Shaimaa has blue eyes , Shaimaa had a male baby with blue eyes . In the above case we can confirm the both genotypes of Abdullah and Shaimaa?
Correct Answer
A. Yes we can
Explanation
The given information states that Abdullah has brown eyes and Shaimaa has blue eyes. Since Shaimaa had a male baby with blue eyes, it indicates that the baby inherited the blue eye gene from Shaimaa. However, we cannot determine Abdullah's genotype solely based on this information. Therefore, we can confirm Shaimaa's genotype for blue eyes but not Abdullah's.
6.
If a male partner with face dimples and pure skin married a female partner that has face freckles but has no dimples , their offspring number of phenotypes probabilities:
Correct Answer
D. 4
Explanation
The offspring of the male partner with face dimples and pure skin and the female partner with face freckles but no dimples can have four different phenotypes. This suggests that there are multiple combinations of genes that can be inherited from each parent, resulting in different physical characteristics in the offspring.
7.
All of the following may carry variable number of chromosomes except:
(choose two)
Correct Answer(s)
B. Brain cells
D. Sperm cells
Explanation
Brain cells and sperm cells are the only two options that carry a fixed number of chromosomes. Liver cells, muscle cells, white blood cells, and skin cells can all have a variable number of chromosomes due to genetic mutations or other factors.
8.
Klinefelter syndrome is an abnormal male sex disorder , choose the correct karyotype representing the case:
Correct Answer
B. Option 2
Explanation
Klinefelter syndrome is a genetic disorder characterized by the presence of an extra X chromosome in males (XXY karyotype). Option 2 is the correct choice as it represents the karyotype of a person with Klinefelter syndrome.
9.
According to Mendel Second law of characters inheritance , all the offspring (first and second) genotypes can be determined from their phenotypes
Correct Answer
B. False
Explanation
According to Mendel's second law of character inheritance, the genotypes of offspring cannot be determined solely from their phenotypes. This is because phenotypes can be influenced by multiple genotypes, making it impossible to accurately predict the exact genotypes based on the observed phenotypes alone. Therefore, the given statement is false.
10.
Within each chromosome, there are two copies of each .............. (complete)
Correct Answer
gene
Explanation
Within each chromosome, there are two copies of each gene. This is because chromosomes come in pairs, with one copy inherited from each parent. Genes are segments of DNA that contain instructions for building proteins, which are essential for the functioning and development of organisms. Having two copies of each gene allows for genetic diversity and provides a backup in case one copy is damaged or mutated.