Like animals, plants must maintain and internal balace, or

aleksklad [387]

Answer:

Adaptation is important for not only animals but humans to survive. If either living things habitat change they must change with it to survive.

8 0

2 years ago

Why is the pairing of nitrogen bases key to understanding how DNA replication occurs?

Burka [1]

The DNA replication occurs by preparing a new strand of DNA that is based on the template strand only. So understanding the nitrogen base pairing is very essential for understanding DNA replication.

<h3> Explanation:</h3>

DNA replication occurs prior to any type of cell division in all organisms. In case of humans, the DNA that is to be replicated needs to be de winded by means of decondensation of chromosomes into chromatin fibres and then to DNA fibres. Then there are enzymes like helicase and gyrase which helps in breaking the hydrogen bonds between two strands of DNA and to open it up for enzymes to get attached.

Then the enzyme DNA dependent DNA polymerase works on both the strands of DNA where it reads the mother DNA strand as a template and then brings deoxyribonucleotides complementary to the template strand and then polymerises it with the previous nucleotide to form a new DNA strand. Thus two DNA strands are produced which are again complementary to each other, leading to the production of a new daughter DNA. So, understanding the complementary base pairing is very essential to understand the DNA replication.

7 0

3 years ago

The passing of __________________ is the basis of heredity. 2. our ________________ encode the instructions that define our trai

cluponka [151]

1. The passing of traits from parents to the offsprings (children) is the basis of heredity. Traits are notable features or qualities in a person, such that each individual has a different combination of traits that makes us unique from others. They are inherited from our parents and passed from generation to generation. That is to our children, then our children to their children and so on.

2. Our genes encode the instructions that define our traits. Traits are majorly defined by the instructions encoded in the genes. However, environment may influences the traits and may play an important role in shaping the traits we posses. Often times these traits may be changed by the environmental factors.

3. Each of us has thousands of genes, which are made of DNA molecules and reside in our chromosomes. Genes are functional or fundamental units of heredity. They are made up of DNA molecules, and act as instructions to make proteins, through a process of transcription and translation. Transcription involves formation of a messenger RNA which then undergoes translation in the cytoplasm to make proteins.The protein formed determine the traits of an individual.

4. In addition to our genes, the Environment we live in also helps define our traits. The expression of genes in organisms may be influenced by environmental factors, these includes the external factors where the organism lives or develops, and also the internal factors such as its hormones and metabolism.

5. Human have two complete sets of 23 chromosomes. A human being has a total of 46 chromosomes (23×2 = 46). This is referred to as a diploid number (2n). Each set is considered to be a one homologous chromosome set. This is the case of of the somatic cells or the body cells which represents a diploid number of chromosomes.

6. When parents conceive a child, each parent contributes one set of chromosomes.This enhances the passing of traits or genes to the child. The egg cell or the ovum from the mother and the sperm cell from the father contain the haploid number (n) or one set of chromosome. During conception the two combines/fuse to form a zygote which is now diploid (2n).

7. Every child receives half of its chromosomes from the mother and another half from the father. During meiosis in the gametes for both mother and father a haploid cell is formed with one set of chromosomes (haploid, n). Therefore, each child contains half number of chromosomes from the mother and the other half from the father making up the diploid number (2n).

8. This transfer takes place at conception, when the father's sperm joins the mother's egg. During conception, fertilization takes place and the sperm cell fuses with the mother cell (ovum) forming a single cell called Zygote. The zygote has the two sets of chromosomes (23 +23 = 46). The cells then divide by mitosis leading to the development of a child.

9. While most cells in our bodies have two sets of chromosomes, or a total of 46 chromosomes, egg and sperm each have 23 chromosomes. The body cells (somatic cells) contain two sets of chromosomes (diploid number, 2n) from mitosis, while the gametes have a single set of chromosomes (haploid, n), from meiosis.

5 0

3 years ago

Which of the following best describes chemical weathering? I need this ASAP

beks73 [17]

Answer:

D

Explanation:

A process that changes the composition of rocks causing them to break down.

7 0

2 years ago

Read 2 more answers

Marcus discovered that sodium (Na) is found in Group 1, Period 3 on the periodic table. Where should Marcus look to find another

Leokris [45]

Answer:

1. A. Group 1

2. B. A chemical change occurred which is evidenced by the change in color of the solution.

3. D. Physical change because the chemical properties of the salt and water remained the same.

4. D. Sphere B will float because it is less dense than water.

5. C. Shredding them into smaller pieces.

6. A. Her model uses eleven white pom-poms.

B. Her model uses twelve black pom-poms.

E. Her model uses eleven yellow pom-poms.

7. B. The liquids have different densities.

8. D. Physical Properties: color, texture Chemical Properties: ability to rust

9. A. Container A will have 1 liter of helium, and container B will have 1 liter of water.

Explanation:

1.

In the periodic table, rows represent the period that they are in, while columns represent the groups that elements are in. Elements in the same group (column) share similar properties. Since Sodium (Na) is found in group 1, elements that are similar in properties would be found in the same group.

2.

A chemical change is marked with a change in color, production of gas, heat, and sometimes smell and light. A chemical change results in new products formed, in which the properties and identities of the reactants change as well because their atoms were rearranged. In this case, the change in color of solution shows that a chemical change had occurred.

3.

Earlier we said that chemical change results in new products, for physical change it does not. The substance will keep its identity. Like in the scenario, the salt and water did mix together, but when they were separated through evaporation, the salt retained its identity and so did the water. The substances involved merely changed phases. So this was a physical change.

4.

If the density of the object is more than the density of the liquid, the object will sink. On the other hand, if the density of the object is less than the density of the liquid, it will float.

If water has a density of 1g/cm³, the object that has the lesser density will float. First you solve for the densities of each object and it can be computed using the formula:

D = m/v

where D = density; m = mass; and v = volume

Sphere A:

$d=\dfrac{m}{v} = \dfrac{24g}{19.4cm^3} = 1.23 g/cm^3$

Sphere B:

$d=\dfrac{m}{v} = \dfrac{13.6g}{17.0cm^3} = 0.8g/cm^3$

So as you can see, only Sphere B has a density less or is less dense than water, so only Sphere B will float.

5.

The groundskeeper shredding leaves is an application of physical change. As you can see, the identity of the leaves would be the same if you just shred them. Even if they change in shape and size, the leaves are still leaves, only smaller.

6.

A stable atom has the same number of electrons and protons. The number of protons is represented by the atomic number of an element.

Sodium has an atomic number of 11. This means that there are 11 protons (yellow pom poms) in a sodium atom. Since it is stable, you can also say that there are 11 electrons (White pom poms) as well.

The number of neutrons can be determined by taking a look at the mass number of an atom. The mass number of sodium is 23. The mass number is the number of protons and neutrons combined.

23 = p + n

23 = 11 + n

23 - 11 = n

12 = n

The number of neutrons would be 12 (black pom poms).

7.

When two liquids do not mix, this means they are immiscible. The layers are formed because of the difference in density. Remember earlier about density and an object or substance's ability to float? Well it applies here too. The liquid on top is less dense than the one below it, so it floats up and the denser liquid sinks.

8.

Physical properties are things that you can observe using your senses. Chemical properties are properties that you can only observe when chemical structure is changed.

Seat cover has a smooth texture.

Physical because it was determined by touch.

The front basket of the bike is purple.

Physical because it was determined by sight.

The bike is rusted.

Chemical because the metal changed its chemical structure as a result of a reaction.

9.

The sealed containers represent a closed system, or a vacuum where nothing goes in or out. In a closed system, just remember that matter is not created, nor destroyed. Simply put, this means that whatever it started with is what will it end up with.

In container A you have 1 L of helium gas, so since the container is sealed, none escaped. This means that you will end up with the same amount of helium gas as you did before. The same goes for the 1L of water in container B.

7 0

2 years ago