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Ivahew [28]
3 years ago
7

Elements and Compoundsplease help me​

Biology
2 answers:
I am Lyosha [343]3 years ago
8 0

Answer:

An element is a substance that cannot be broken down into any other substance. made up or consisting of several parts or elements

Explanation:

den301095 [7]3 years ago
7 0

Answer:

<u><em>Question 1:</em></u>

An element is a pure substance which cannot be broken down by chemical means.

<u><em>Question 2:</em></u>

A molecule is a group or cluster of two or more atoms held together by chemical bonds. A compound is a substance or material which is formed by two or more different types of elements which are combined chemically in a fixed proportion.

<u><em>Question 3:</em></u>

Electrons, Protons and Neutrons

<u><em>Question 4:</em></u>

Dmitri Mendeleev in 1869 developed the periodic table.

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By about ____ months of age, different circuits in the brain begin to control infants’ looking at faces, allowing infants to dis
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Answer: 2-3

Explanation:

A biological neural network or neural circuit is a set of ordered synaptic connections that occur as a result of the binding of neurons to others in their corresponding regions following neural migration. At birth, a baby has an average of 100 billion neurons, but few neural connections. These will multiply as the child grows, through environmental, sensory, cognitive and movement stimulation. <u>Stimulating mobility and physical activity also has a positive effect on cognitive functioning by modifying the activity of certain brain areas</u>. Physical exercise has beneficial effects on brain function, such as promoting neuroplasticity and increasing learning and memory performance, which may be due to increased expression of various neural growth factors.

<u>Finally, environmental stimulation is basic for harmonious brain development and for laying the neurophysiological foundations of our children's future brains. </u>Thus, there are many mechanisms that nature has at its disposal to prevent babies from being left helpless.  All of them favour their relationship with adults and thus their neurons, at a time of maximum growth of their extensions, can form the brain circuits that allow the acquisitions that make them advance in their neurodevelopment. If babies do not receive from their adults sufficient affection and attention, brain growth will be much less and their neurodevelopment will inevitably be delayed, because what makes the brain grow and change is precisely the creation of new circuits as it learns new things, and those who can learn most are the most experienced. By aboyt 2-3 months is when circuits of the brain begin to be created.

7 0
3 years ago
Read 2 more answers
Amoeba Sisters Video Recap: DNA Replication
Sergio039 [100]

Before starting the explanation in the amoeba sister video, they explain what DNA replication is. We can say that DNA, which in eukaryotic cells is located in the nucleus, contains all the genetic information of a being and its duplication process is important for cell growth, reproduction and repair.

<h3 /><h3>What is DNA replication?</h3>

A DNA molecule is made up of two strands that complement each other. For example, if we have an F and an F' strand, in the replication process the strands separate and are used as templates for the formation of complementary strands. Thus, the nucleotide sequence of F determines the sequence of a new F' strand, and F' indicates the composition of a new F strand.

<h3>DNA replication process</h3>

In the video of the amoebas sisters it is briefly explained that..

  1. DNA replication occurs in the 5' → 3' direction and the strands are separated by the action of enzymes, which break the bonds between the nitrogenous bases and unwind the strands, opening the double helix.
  2. As DNA uncoiling takes place, other enzymes act to catalyze the synthesis of two new sequences using the parent strands as a template. Each strand created joins an original strand of DNA. Therefore, the process is classified as semi-conservative.
  3. DNA is a double helix molecule and for its duplication to occur, the first step is to unpack this structure by the action of the DNA helicase enzyme. The helicase recognizes the origin of replication and works by breaking the hydrogen bonds in the nitrogenous bases A-T and C-G. This process occurs at several points and forms "replication bubbles".
  4. As the bonds unravel, it's like a zipper opening, so this step gives rise to a Y-shaped structure called the replication fork, the starting point of duplication.
  5. The primase enzyme is responsible for synthesizing a portion of RNA, called a primer. In this step, several primers are generated and are joined to the chain to start DNA synthesis.
  6. The DNA polymerase enzyme is the replication enzyme responsible for extending the new strand by adding the bases (A, C, G and T). This step is directed from the 5' end, with a phosphate group, to the 3' end, with a hydroxyl group. This phase is called continuous replication.
  7. Among the primers attached to the original strand, several pieces of DNA are attached and are called Okazaki fragments. As the sections will need to be joined later, this phase is called delayed.
  8. The exonuclease enzyme is responsible for removing the primers from the original strands after the formation of continuous and discontinuous strands. To avoid sequencing errors, a review and, if necessary, a correction is performed by another exonuclease.
  9. The enzyme DNA ligase causes the DNA fragments to be joined and the DNA sequenced into two continuous strands.

thus, in a simple way, how DNA replication occurs in the video of the amoebas sisters.

learn more about DNA in brainly.com/question/264225?referrer=searchResults

5 0
3 years ago
Which of the following blood vessels uses elasticity to push blood further along the bloodstream?
PolarNik [594]
The answer is Arteries 

Arteries carry oxygen-rich blood from the heart to capillaries. On the contrary, veins carry blood without oxygen from the capillaries to the heart. 
Arteries are very flexible and yet strong blood vessels so that efficient transport of oxygen-rich blood along the bloodstream through the organism is enabled.
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3 years ago
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Guinea pig coat color is determined by a single gene. The allele for black coat color is dominant to brown. In a cross between t
Gwar [14]

Answer:

In a cross between two black-haired guinea pigs, 20 offspring are born. If both parents were heterozygous, probability would predict that approximately 1 out of 20 offspring would have brown hair

Explanation:

The two parents crossed were heterozygous dominant black coat color, after crossing 75% gives dominant black color coat while 25% gives only brown coat color homozygous

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Where do homologous chromosomes exchange genetic material through crossing over?
zvonat [6]

Answer: C) Centromeres

Explanation: Centromeres are involved in crossing over, none of the other ones are.

8 0
4 years ago
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