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

Select the mismatch

The morphological nature of the edible part of coconut is:

1. Cotyledon

2. Endosperm

3. Pericarp

4. Perisperm

Double fertilization is exhibited by:

Spliceosomes are not found in cells of;

1. Fungi

2. Animals

3. Bacteria

4. Plants

The association of histone H1 with a nucleosome indicates:

1. DNA replication is occurring

2. The DNA is condensed into a chromatin fibre

3. The DNA double helix is exposed

4. Transcription is occurring

The region of Biosphere Reserve which is legally protected and where no human activity is allowed is known as

1. Buffer Zone

2. Transition Zone

3. Restoration Zone 

4. Core Zone