Saturday, December 19, 2020

Biology A/L Structured essay question

2. A. (i) Nucleotides are the buildings blocks of nucleic acids. What are the 2 different types of nucleotides which make nucleic acids?

(a)

(b)

(ii) What are the pairs of nitrogen bases which make bonds between two strands of DNA molecule?

(a)

(b)

(iii) Name three similarities between RNA and DNA molecules

DNA RNA

(a)

(b)

(c)

(iv) (a) There are three types of RNA molecules. Name the RNA type which does the following function.

(a) Site for assembling of polypeptide chains-

(b) Copying genetic information

(B) (i) Nucleotides do major functions in a living body other than forming nucleic acids. Name one function of each of the following nucleotides.

(a) ATP-

(b) FAD

(c) NADP+

(ii) Light microscopes and Transmission electron microscopes are very important in studying cytology. Compare the use of two instruments regarding the following facts.

Fact Light Microscope T Electron microscope

(a). Staining of the specimen

(b). Converging of beams to the

Specimen.

(c). Observing the specimen

(iii) Name the biologist who put forwarded the following fact regarding cell theory.

“All cells arise from pre-existing cells.”

(iv) Name two features possessed by all living cells


(C) (i) What are the differences in genetic material found in prokaryotes and eukaryotes?


(ii) Name three common features found in bacteria, archaea, and cyanobacteria.

(a)

(b)

(c)

(iii) Given below are some of the chemicals found as cell wall materials in various organisms. Name the organism that possesses them in front of the chemical compound.

(a) Peptidoglycan-

(b) Chitin-

(c) Protein –

(iv) Name 2 differences between the flagella of bacteria and the flagella of Euglena.

                                          Answer

2.A. (i) Nucleotides are the buildings blocks of nucleic acids. What are the 2 different types of nucleotides?

(a) Ribonucleotide

(b) Deoxy ribonucleotide

(ii) What are the pairs of nitrogen bases make bonds between two strands of DNA molecule?

(a) Adinine and Thyamin

(b) Cytocin and Guanin

(iii) Name three similarities between RNA and DNA molecules

(a) Both have sugar-phosphate bonds

(b) Both have purin, Nitrogen bases

(iv) (a) There are three types of RNA molecules. Name the RNA type which does the following function.

(a) Site for assembling of polypeptide chains- rRNA

(b) Copying genetic information- mRNA

(B) (i) Nucleotides do major functions in the living body other than forming nucleic acids. Name one function of each of the following nucleotides.

(a) ATP- Universal energy carries

(b) FAD- An electron carrier

(c) NADP+ - As a reducing agent

(ii) Light microscopes and Transmission electron microscopes are very important in studying cytology. Compare the use of two instruments regarding the following facts.

Fact Light Microscope Electron microscope

(a). Staining of the specimen Dyes are used heavy metals are used

(b). Converging of beams to the

Specimen. Glass lenses are used Magnets are used

(c). Observing the specimen naked eyes can be used. Only micrographs can be observed

(iii) Who is the biologist who put forward the following fact regarding cell theory.

“All cells arise from pre-existing cells.”

Rudolff Virchow

(iv) Name two features possessed by all living cells.

Surrounded by a plasma membrane

Carry DNA as genetic material

(C) (i) What are the differences in genetic material found in prokaryotes and eukaryotes?

Prokaryotes Eukaryotes

Circular DNA Linear DNA

Not associated with protein Associated with protein

(ii) Name three common features found in bacteria, archaea, and cyanobacteria.

(a) Circular DNA

(b) Not associated with protein

(c) 70s ribosomes

(iii) Given below are some of the chemicals found as cell wall materials in various organisms. Name the organism that possesses them in front of the chemical compound.

(a) Peptidoglycan- Cyanobacteria

(b) Chitin- Fungi

(c) Protein – Archi bacteria

(iv) Name 2 differences between the flagella of bacteria and the flagella of Euglena.

flagella of bacteria flagella of Euglena

No microtubules in bacterial flagella microtubules are present in flagella of Euglena

Diameter is 20nm in bacterial flagella Diameter is 200 nm in flagella of Euglena



No comments:

Post a Comment

Sri Lankan true cinnamon

                                🌿 Ceylon (Sri Lankan) Cinnamon — The True Cinnamon with Rich History and Benefits Introduction Ceylon cinna...