Hello there Jonnromeroo, thank you for asking a question here on Brainly!
You Asked ➤ Which of the following processes begins when a star enters the main sequence?
↴ OUR CHOICES ↴
A: Nuclear fission
B: Nuclear fusion
C: Condensation of a nebula
D: Appearance of a supernova
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Answer ➤ B: Nuclear fusion
Explanation: When a star begins the process of being created, it is hot and dense. Really hot and dense! It begins to start fusing with helium which is the start of its main sequence called nuclear fusion.
I hope this answer is helpful to you, but please let me know if you have any other questions regarding it.
<em>- Qamar </em>
Let's discuss first about difference between micro- and macro-nutrients. Micronutrients are those which are needed in small quantities and their function is not that vast. But macronutrients are the ones which control all the metabolic cycles of the cell, so they are needed in large quantities. This is the basic difference between the two terms.
Proteins are macro-nutrients because they are needed in large amount, as they are involved in some of the most important functions of our body. For example, proteins act as enzymes, involved in immunity, maintaining homeostasis of the body, etc. That is why they are considered as macronutrients.
The term ''tissue'' refers to a group of similar cells. Being a combination of equal cells, a tissue has the same function in any part of the body.
The four types of tissues are:
. The epithelial tissue
. The connective tissue
. Muscle tissue
. The nervous tissue
. The epithelial tissue serves as a cover, among these are the skin and the lining of several ducts inside the body. It is divided into two general classifications: Simple Epithelium and Stratified Epithelium.
. The connective tissue supports and joins other tissues such as bone, blood and lymphatic as well as adipose tissue and reticular tissue.
. Muscle tissue consists of striated or voluntary muscles that move the skeleton and smooth muscle, such as the one that surrounds the stomach. It is divided into three types: Skeletal Muscle Tissue, Cardiac Muscle Tissue and Smooth Muscle Tissue.
. Nervous tissue is formed by nerve cells or neurons and serves to carry messages to and from various parts of the body. This tissue is present mostly in the brains and spinal cord. It has two types of tissue: The Nerve Cell and the Neuroglia.
For the answer to the question above, I believe the answer is <span>A. vaccine helps the body develop memory cells that make immunity last, whereas injection of antibodies only produces a temporary immunity.
I hope my answer helped you. Have a nice day!
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I believe
1.b
2.c
3.b
4.d
5.a
6.b
7.b
8.c
9.d
10.b
