Tag: the origin of cells and cell division

Questions Related to the origin of cells and cell division

Entry of pollen tube in the ovule through integument is called

botany modes of reproduction introduction to flower pre fertilization - plants sexual reproduction in flowering plants the origin of cells and cell division

  1. Chalazogamy

  2. Basigamy

  3. Mesogamy

  4. Porogamy

Show answer
Correct Option: C
Explanation:
The entry of pollen tube in the ovule through integument is commonly known as mesogamy. It is commonly seen in plants like Cucurbita, Populus, etc.
So, the correct answer is 'Mesogamy'.

The apical growing region of pollen tube called

botany modes of reproduction introduction to flower pre fertilization - plants sexual reproduction in flowering plants the origin of cells and cell division

  1. Growing zone

  2. Cap block

  3. Non-vacuolate region

  4. Organelle region

Show answer
Correct Option: B
Explanation:

Apical zone of pollen tube contains abundant vesicles but lacks cell organelles. It is hemisphere in shape and transparent in nature. This transparent apical growing region of pollen tube is called as cap block. It exists only until the tube is growing. It disappears as soon as the growth ceases. 

Thus, the correct answer is option B. 

The functional part of the pollen tube is separate from the rest by

botany modes of reproduction introduction to flower pre fertilization - plants sexual reproduction in flowering plants the origin of cells and cell division

  1. Vacuoles

  2. Callose plugs

  3. Septa

  4. Both B and C

Show answer
Correct Option: B
Explanation:

Callose is a beta-1,3-glucan. It is the major component of the pollen tube cell wall. It is also deposited within the cytoplasm as distinct callose grains. This leads to the formation of callose plugs. Callose plugs separate the living, growing and functional part of the pollen tube in the tip from the remaining degenerating part.

Thus, the correct answer is option B.

Which of the following is not a co-enzyme?

biology enzymes classification of enzyme enzymes classification and cofactors the origin of cells and cell division

  1. NAD

  2. NADP

  3. FAD

  4. ATP

Show answer
Correct Option: D
Explanation:

ATP or adenosine triphosphate is a nucleotide. It is not a co-enzyme.

Select the type of enzyme involved in the above reaction.

$\boxed{S - G + S' \rightarrow S + S' - G}$

biology enzymes classification of enzyme enzymes classification and cofactors the origin of cells and cell division

  1. Dehydrogenase

  2. Transferase

  3. Hydrolase

  4. Lyase

  5. Isomerase

Show answer
Correct Option: B
Explanation:

Transferases are the enzymes that catalyze group transfer reactions. In the figure, one group G has been transferred to another group S'. It is a classical example of a group transfer reaction.

Who proposed the principle of "Induced fit"?

biology enzymes classification of enzyme enzymes classification and cofactors the origin of cells and cell division

  1. Jacob

  2. Fischer

  3. Koshland

  4. Laderberg

Show answer
Correct Option: C
Explanation:

The induced-fit model is proposed by Daniel Koshland in 1958. It is the most accepted model for enzyme-substrate complex. It describes the formation of the Enzyme substrate as a result of the interaction between the substrate and a flexible active site which means exposure of an enzyme to a substrate causes the active site of the enzyme to change shape in order to allow the enzyme and substrate to bind. Hence option C is correct.

NADP is

biology enzymes classification of enzyme enzymes classification and cofactors the origin of cells and cell division

  1. A coenzyme

  2. A part of tRNA

  3. An enzyme

  4. A part of rRNA

Show answer
Correct Option: A
Explanation:

Coenzymes are organic cofactors which are required for enzymatic action of certain enzymes. NADP is a coenzyme form of vitamin nicotinamide or niacin.

DNA polymerase enzyme is responsible for the synthesis of

biology enzymes classification of enzyme enzymes classification and cofactors the origin of cells and cell division

  1. DNA from RNA

  2. DNA from DNA

  3. RNA from DNA

  4. RNA from RNA

Show answer
Correct Option: B
Explanation:

DNA polymerase is an enzyme used in DNA replication. It synthesizes DNA on a DNA template. Bacteria have three different DNA polymerases, i.e., DNA pol I, DNA pol II and DNA pol III; while eukaryotes have several DNA polymerase enzymes.

Which of the following enzyme can form RNA from DNA?

biology enzymes classification of enzyme enzymes classification and cofactors the origin of cells and cell division

  1. Restriction enzyme

  2. DNA polymerase

  3. RNA polymerase

  4. Reverse transcriptase

Show answer
Correct Option: C
Explanation:

RNA polymerase participates in RNA synthesis during transcription process. It synthesizes RNA on DNA template.

Basically how many types of enzymes have been recognised by International Union of Biochemistry?

biology enzymes classification of enzyme enzymes classification and cofactors the origin of cells and cell division

  1. 4

  2. 5

  3. 6

  4. 8

Show answer
Correct Option: C
Explanation:

According to the modern classification system given by International Union of Biochemistry, enzymes have been classified into six classes as follows :
Class First is Oxidoreductase.
Class Second is Transferase.
Class Third is Hydrolase.
Class Fourth is Lyase.
Class Fifth is Isomerase.
Class Sixth is Ligase.