ورقة عمل الأحياء لامتحانات القبول في التمريض مع الإجابات

What is a mutagen?

1. AAn enzyme that copies DNA
2. BA cell that divides without control
3. CSomething that can cause changes in DNA
4. DA protein that repairs damaged DNA

ما التركيب الرئيس للغشاء الخلوي؟

1. Aصفيحة واحدة من جزيئات النشا
2. Bطبقة فوسفوليبيدية مزدوجة تتخللها بروتينات
3. Cطبقة صلبة من ألياف السليلوز واللجنين
4. Dجدار سميك من الببتيدوغليكان

What is a trait that is controlled by many genes called?

1. AA sex-linked trait
2. BA codominant trait
3. CA recessive trait
4. DA polygenic trait

Red-green colour blindness is X-linked recessive. A colour-blind woman (XᵇXᵇ) has children with a man with normal colour vision (XᴮY). What fraction of their sons is expected to be colour-blind?

1. ANone
2. BOne half
3. COne quarter
4. DAll

Many vitamins act as coenzymes. What does this mean?

1. AThey help enzymes carry out their reactions
2. BThey are digested to release large amounts of energy
3. CThey are built into the cell membrane
4. DThey replace enzymes that have been denatured

Why does PCR use a DNA polymerase taken from bacteria that live in hot springs?

1. AIt copies RNA as well as DNA
2. BIt makes the DNA strands stick together
3. CIt works only in the dark, like the bacteria it comes from
4. DIt survives the high temperatures used to separate the strands

A child's DNA profile has bands A, B, C and D. The mother has bands A and C. Man 1 has bands B and D, man 2 has A and E, and man 3 has C and F. Which man could be the biological father?

1. AMan 2
2. BMan 1
3. CMan 3
4. DNone of them

Two genes lie very close together on the same chromosome. In a test cross, most offspring look like the parents instead of the expected 1:1:1:1 ratio. Why?

1. AA frameshift mutation happened in both genes
2. BBoth genes show incomplete dominance
3. CThe genes are on different chromosomes and assort independently
4. DThe genes are linked and are rarely separated by crossing over