Cell biology worksheet with answers

Which structure is found in plant cells but not in animal cells?

1. AMitochondria
2. BCell membrane
3. CRibosomes
4. DCell wall

In chromatin, DNA is wrapped around which proteins?

1. AActins
2. BTubulins
3. CCollagens
4. DHistones

What is a mutation?

1. AA change in the shape of the cell
2. BA change in the DNA base sequence
3. CThe splitting of a chromosome during mitosis
4. DThe normal copying of DNA

Which molecules can cross a phospholipid bilayer most easily by simple diffusion?

1. ASmall non-polar molecules such as O₂ and CO₂
2. BProteins such as albumin
3. CLarge polar molecules such as glucose
4. DIons such as Na⁺ and K⁺

Transcription produces:

1. AProtein from mRNA
2. BDNA from RNA
3. CmRNA from a DNA template
4. DDNA from DNA

What is crossing over during meiosis?

1. ASeparation of sister chromatids as they move to opposite poles in anaphase II
2. BCopying of DNA before division
3. CFusion of two gametes
4. DExchange of genetic material between homologous chromosomes in prophase I

Why can translation in bacteria begin before transcription of the mRNA is finished?

1. ABacterial ribosomes can read the DNA template directly in the cytoplasm
2. BThere is no nuclear envelope separating DNA from ribosomes
3. CBacterial mRNA is spliced faster
4. DBacteria do not use mRNA

In E. coli, under which conditions is the lac operon most strongly transcribed?

1. ALactose absent and glucose present
2. BLactose present and glucose absent
3. CBoth lactose and glucose absent
4. DBoth lactose and glucose present