1. Which of the following combinations correctly represents the genetic materials in prokaryotes and eukaryotes respectively?

a) Nucleoid and Chromatin

b) chromatin and Nucleoid

c) Nucleoid and Nucleolus

d) Nucleolus and Chromatin

Answer : a) Nucleoid and Chromatin

Explanation  :

Prokaryotes:

• They do not contain a well-defined nucleus.
• It has nucleoids inside the cell. It is this nucleoid that contains its genetic material.

Eukaryotes:

• It have true nuclei.
• Its nucleus represent chromatin.
• The chromatin consists of DNA and proteins

2. Lysosomes are sacs of the cell filled with digestive enzymes. These digestive enzymes are synthesized by

a) Golgi bodies

b) smooth endoplasmic reticulum

c) rough endoplasmic reticulum

d) lysosome itself

Answer : c) rough endoplasmic reticulum

Explanation  :

• Lysosomes are membrane-bound sacs filled with digestive enzymes. These enzymes are made by rough endoplastic reticulum.
• Function : Lysosomes are a kind of waste disposal system of the cell. These help to keep the cell clean by digesting any foreign material as well as worn-out cell organelles.

3. Which of the following best represents the cells of a meristem of plant?

a) Dense cytoplasm, thin cell wall, large nuclei and absence of vacuoles

b) Dense cytoplasm, thin cell wall, large nuclei and large vacuoles

c) Dense cytoplasm, thin cell wall, small nuclei and absence of vacuoles

d) Dense cytoplasm, thick cell wall, small nuclei and large vacuoles

Answer : a) Dense cytoplasm, thin cell wall, large nuclei and absence of vacuoles

Explanation  :

• Cells of meristematic tissue are very active, they have dense cytoplasm, thin cellulose walls and prominent nuclei.
• They lack vacuoles.

4. Which one of the following animals has a four- chambered heart?

a) King cobra

b) Turtle

c) Chameleon

d) Crocodile

Answer : d) Crocodile

Explanation  :

• Pisces-Two chambers,
• Amphibians-Three-chambered heart
• Reptiles-Three-chambered heart,Exception:crocodiles have four heart chambers
• Aves-Four-chambered heart.
• Mammalia-Four-chambered hearts.

5. One way of incorporating desired characters into crop varieties is hybridization. In this process, there is crossing between genetically dissimilar plants. Which one of the following crossings will not refer to hybridization?

a) Intervarietal

b) Interspecific

c) Intergenic

d) Intragenic

Answer : d) Intragenic

Explanation  :

• Intervarietal hybridization - The cross between the plants belonging to two different varieties of the same species and is also known as intraspecific hybridization. This technique has been the basis of improving self-pollinated as well as cross pollinated crops.
• Interspecific hybridization - The cross between the plants belonging to different species belonging to the same genus is also called intragenic hybridization. It is commonly used for transferring the genes of disease, insect, pest and drought resistance from one species to another.
• Intergeneric hybridization - The crosses are made between the plants belonging to two different genera. The disadvantages are hybrid sterility, time consuming and expensive procedure.

6. Depending on the requirements, plant nutrients are classified as micronutrients and macronutrients. Which one of the following is an example of a macronutrient?

a) Manganese

b) Copper

c) Magnesium

d) Chlorine

Answer : c) Magnesium

Explanation  :

• Macronutrients: Elements which are present in large amounts in plant tissues are called macronutrients. They are in excess of 10 mole per kg of dry matter. Carbon, hydrogen, oxygen, nitrogen, phosphorous, sulphur, potassium, calcium and magnesium are the macronutrients.
• Micronutrients: Elements which are present in small amounts, i.e. less than 10 mole per kg of dry matter are called micronutrients. Iron, manganese, copper, molybdenum, zinc, copper, boron, chlorine and nickel are the micronutrients.

7. Buds produced in the notches along the leaf margin of Bryophyllum fall on soil and develop into new plants. This is an example of which one of the following types of reproduction?

a) Vegetative propagation

b) Budding

c) Spore formation

d) Regeneration

Answer : a) Vegetative propagation

Explanation  :

• There are many plants in which parts like the root, stem and leaves develop into new plants under appropriate conditions.
• Similarly buds produced in the notches along the leaf margin of Bryophyllum fall on the soil and develop into new plants

8. Phloem tissues are mostly responsible for transport of

a) water

b) oxygen

c) minerals

d) food

Answer : d) food

Explanation  :

• The plant has vascular tissue. It consists of the xylem and phloem.
• The phloem consists of parenchyma, fibers, sieve tubes, and companion cells.
• Phloem tissue is mostly responsible for the transport of food.

9. The organisms that prefer high salt concentration habitats refer to as

a) alkaliphiles

b) calcifuges

c) halophiles

d) nitrophiles

Answer : c) halophiles

Explanation  :

• Alkaliphiles are a class of extremophilic microbes capable of survival in alkaline (pH roughly 8.5–11)
• Calcifuge is a plant that does not tolerate alkaline (basic) soil.
• Halophile is an organism, especially a microorganism, that grows in or can tolerate saline conditions.
• Nitrophile plant is a plant that prefers to grow in soil or water that is rich in nitrates.