Explanation

 The first true mammals evolved during the Triassic Period (around 225 million years ago), emerging from therapsid reptiles.

Explanation

Humans have 23 pairs of chromosomes, 46 in all: 44 autosomes and 2 sex chromosomes.

Explanation

When a soap bubble is charged, the repulsive forces between like charges on the surface of the bubble cause the bubble to contract, decreasing its size.

Explanation

Cilia and flagella have a characteristic "9+2" arrangement of microtubules: nine outer pairs and two central single tubules.

Explanation

An atom is a particle of matter that uniquely defines a chemical element

 It also is the smallest unit of matter 

Explanation

Explanation

The steroid hormones are synthesized in the :

the adrenal cortex,

the gonads,

and the placenta

The steroid hormones are all derived from cholesterol and many are of clinical importance

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Cholesterol is the fundamental building block for all other steroids in the body.

Cholesterol is also the precursor of other important: steroid metabolites including bile salts and steroid hormones.

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ND11-12-2022

Explanation

In Ascidian embryos, the grey crescent gives rise to the notochord. 

The gray crescent:

• In ascidian development, the gray crescent is a region of pigmented cytoplasm located at the posterior of the fertilized egg.
• It is important for determining the future location of the notochord and neural tube. 

Notochord formation:

• The cells derived from the gray crescent are specifically destined to form the notochord, a rod-like structure that provides structural support during development. 

Explanation

Blotting paper absorbs the water through capillary action only as thin threads like structure are present in blotting paper.

Explanation

A carbocation is a carbon atom with a positive charge attached to three other atoms or groups.