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3 years ago

When did people begin to notice that coastlines if continents fit together like a puzzle

Biology

1 answer:

pashok25 [27]3 years ago

6 0

Answer:

B. When Alfred Wegener propose the idea of continental drift

Explanation:

The first true explanation came from Alfred Wegener, who proposed the Plate Tectonic Theory. This theory stated, in a nutshell, that the continents different pieces that collided together at faults.

Technically, explorers found out this way back. If you consider this the answer choice, then C is your best answer.

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a. What do the letters R and I represent ? b. What is the genotype of the pink-flowered snapdragons? c. Explain whether the alle

-Dominant- [34]

Answer:

a) R= allele for red colored flower

I= Allele for ivory flowers

b) Genotype of pink flowered plant: RI

c) Incomplete dominance

d) 100%

Explanation:

When the dominant allele is not able to fully mask the expression of the recessive allele in the heterozygous state, it is said to be incomplete dominance. The R and I alleles impart red and ivory color respectively to the flowers of the snapdragon plant. The heterozygous genotype "RI" imparts a pink color to the flowers and therefore, the alleles are said to exhibit incomplete dominance.

The genotype of red-flowered snapdragon plant = RR. The genotype of ivory flowered snapdragon plant= II. When a red-flowered snapdragon plant is crossed with an ivory flowered snapdragon plant, the progeny is heterozygous in nature with the "RI" genotype. The phenotype of the progeny is "Pink flower" since the R allele is incompletely dominant over the allele I.

5 0

3 years ago

What number of cells is in metaphase

Mrrafil [7]

There is only one cell

3 0

3 years ago

Read 2 more answers

Which organ systems function as control systems, communicating with other cells and organs to regulate their activities?

alekssr [168]

The Nervous & Endocrine Systems.

4 0

3 years ago

Construct a Venn diagram that compares and contrasts sexual and asexual reproduction.

mrs_skeptik [129]

The Venn diagram makes a comparison between categories. Intersection: Cell division/Asexual: diploid, somatic, mitosis, genetically identica/Sexual: haploid, gamete, meiosis, chromosomes separate , genetically different.

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A Venn Diagram is represented as two or more circles with some degree of superposition between them. It is used to make comparisons expressing similitudes and differences between things.

Each circle represents a category -in this example, sexual and asexual reproduction-.

The superposed area is named intersection and shows things in common between the two categories.

We already know that sexual reproduction occurs by the process of meiosis, while asexual reproduction occurs by mitosis.

In superior organisms, there are two types of cells: Somatic cells and germ cells.

The somatic cells are diploid (2n), meaning that each cell has a pair of equal chromosomes. The somatic cells are all the body cells except for the sexual ones, and they reproduce by the process of mitosis.

In somatic cells, one of the sets of chromosomes is inherited from the maternal side, while the other homologous set of chromosomes is inherited from the paternal side. Hence, the number of chromosomes in these double sets of the somatic cells is diploid, 2n.

Mitosis is a process through which, from a diploid somatic cell (2n), two identical daughter diploid cells (2n) are produced.

First, occurs duplication of the cell content, and then the separation into two new cells happens.

Germ cells suffer mitosis and meiosis.

Through meiosis, germ cells produce gametes, called sperm and egg cells, through the gametogenesis process.

Gametes are haploid (n) with half the number of chromosomes that might be found in the somatic cells.

During gamete formation, the pairs of homologous chromosomes separate after crossing over. Then, sister chromatids also separate. The result is the formation of four gametes.

Each gamete has different information from the combination of homologous chromosomes belonging to the father and to the mother.

Gametes' destiny is to merge in the process of fecundation, during which a new diploid cell called zygote emerges through fertilization.

The zygote is a complete cell that suffers successive mitosis to form the new organism.

Venn Diagram

Intersection area: Cell division

Asexual: diploid, somatic, mitosis, genetically identical

Sexual: haploid, gamete, meiosis, chromosomes separate , genetically different.

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You can learn more about the Venn diagram at

brainly.com/question/1703814

7 0

2 years ago

When an atom that has no change loses two electrons, it becomes a ?

densk [106]

Question: When an atom that has no charge loses two electrons, it becomes a:

A: positive ion.

B: negative ion.

C: positive isotope.

D: negative isotope.

Answer:

When an atom that has no change loses two electrons, it becomes "positive ion".

Explanation:

It is known that electrons hold a negative charge. So, when the negative charge that is electrons are taken out an atom then the number of electrons become less in number as compared to the number of protons. Hence, the atom attains a positive charge.An isotope is formed when an atom shows same number of protons and different number of neutrons. So, when an atom loses 2 electrons there will be no change in the number of neutrons. Therefore, an isotope will not form.Thus, it is concluded that when an atom with no charge loses two electrons, it becomes a positive ion.

8 0

3 years ago