Question

Consider the following statements and choose the correct one:

• A. Plant cells have centrioles which are absent in almost all animal cells.
• B. Ribosomes are the site of protein synthesis.
• C. The middle lamella is a layer mainly of calcium carbonate which holds the different neighboring cells together
• D. In all animal cells, steroidal hormones are synthesized by smooth endoplasmic reticulum

Answer 1

Answer: (B), (D)

In all animal cells, steroidal hormones are synthesized by smooth endoplasmic reticulum

The correct options are (B) and (D):

Explanation of the correct option:

Option B:

1. Ribosomes are made up of rRNA and ribosomal proteins.
2. In prokaryotes, ribosomes are of 70S type.
3. In eukaryotes, ribosomes are of 80S type.
4. It synthesizes protein.

Option D:

1. The Smooth Endoplasmic Reticulum does not contain ribosomes.
2. Instead, they contain steroid secreting cells.
3. These cells synthesize steroidal hormones.

Explanation of the incorrect option:

Option A:

1. Centrioles are present in animal cells.
2. It is absent in most plant cells.

Option C:

1. Middle lamella is present between two cells in plants.
2. It is made up of calcium pectate, not calcium carbonate.
3. Apart from that, it is also made up of magnesium pectate.

Final answer: Ribosomes are the site of protein synthesis and in all animal cells, steroidal hormones synthesized by smooth endoplasmic reticulum are the correct statements.