Frog’s heart when taken out of the body continues to beat for some time. 
Select the best option from the following statements. 
(a) Frog is a poikilotherm. 
(b) Frog does not have any coronary circulation. 
(c) Heart is "myogenic" in nature 
(d) Heart is autoexcitable

1. Only (d)

2. (a) and (b)

3. (c) and (d)

4. Only (c)

Homozygous pure lines in cattle can be obtained by:

1. Mating of unrelated individuals of same breed.

2. Mating of individuals of different breed.

3. Mating of individuals of different species.

4. Mating of related individuals of same breed.

Identify the wrong statement in the context of heartwood:

1. It is highly durable

2. It conducts water and minerals efficiently

3. It comprises dead elements with highly lignified walls

4. Organic compounds are deposited in it

Anaphase Promoting Complex (APC) is protein degradation machinery necessary for proper mitosis of animal cells. If APC is defective in a human cell, which of the following is expected to occur?

1. Chromosomes will be fragmented

2. Chromosomes will not segregate

3. Recombination of chromosome arms will occur

4. Chromosomes will not condense

Which of the following cell organelles is responsible for extracting energy from carbohydrates to form ATP?
1. Ribosome
2. Chloroplast
3. Mitochondrion
4. Lysosome

Mycorrhizae are the example of:

1. Amensalism

2. Antibiosis

3. Mutualism

4. Fungistasis

Out of ‘X’ pairs of ribs in humans only 'Y' pairs are true ribs. Select the option that correctly represents values of X and Y and provides their explanation:

In the case of Poriferans, the spongocoel is lined with flagellated cells called:

1. Oscula

2. Choanocytes

3. Mesenchymal cells

4. Ostia

Which one of the following statements is not valid for aerosols?

1. They alter rainfall and monsoon patterns

2. They caused increased agricultural productivity.

3. They have negative impact on agricultural land.

4. They are harmful to human health.

A baby boy aged two years is admitted to play school and passes through a dental check-up. The dentist observed that the boy had twenty teeth. Which teeth were absent in the boy?

1. Canines

2. Pre-molars

3. Molars

4. Incisors