ورقة عمل الأحياء لامتحانات القبول في التمريض مع الإجابات

Which molecules, made by immune cells, bind to specific antigens?

1. AHormones
2. BPhospholipids
3. CAntibodies
4. DEnzymes

Which group of biomolecules forms the basic bilayer of the cell membrane and also stores long-term energy?

1. AProteins
2. BCarbohydrates
3. CLipids
4. DNucleic acids

What is a heterotroph?

1. AAn organism with no cells
2. BAn organism that lives only in water
3. CAn organism that makes its own food by photosynthesis
4. DAn organism that gets its food from other organisms

Sickle cell disease is caused by a single base change that replaces one amino acid in haemoglobin. What type of mutation is this?

1. AA silent mutation
2. BA nonsense mutation
3. CA frameshift mutation
4. DA missense mutation

In gel electrophoresis, why does DNA move towards the positive electrode?

1. ADNA has a negative charge from its phosphate groups
2. BDNA has a positive charge from the nitrogen bases it contains
3. CDNA is pulled by gravity through the gel
4. DDNA has no charge and moves at random

Human adult height varies across a smooth, continuous range rather than falling into a few separate groups. What is the best explanation?

1. AIt is controlled by many genes and also affected by environment
2. BIt is an X-linked recessive trait
3. CIt is controlled only by the environment
4. DIt is controlled by one gene with two alleles and full dominance

Why do phospholipids arrange themselves into a double layer in water?

1. AThey carry a strong positive charge on both ends
2. BTheir heads are hydrophilic and their tails are hydrophobic
3. CTheir heads are hydrophobic and their tails are hydrophilic
4. DThey are fully soluble in water

A farmer's crops grow poorly in soil lacking nitrates. Why do plants need nitrogen?

1. ATo make glucose during photosynthesis
2. BTo absorb more carbon dioxide through the stomata
3. CTo build cellulose cell walls
4. DTo make amino acids, proteins and nucleic acids