Explanation:
Crossing over, or genetic recombination contributes to genetic variation and diversity.
In early Prophase I of meiosis, crossing over occurs. This is the exchange of segments of chromosome, between non-sister homologous or similar chromatids crossing over happens at chiasmata, the point where non-sister chromosomes are joined. The chromosome pairs form tetrads held together at chiasmata.
Further Explanation:
All the genetic information within the eukaryotic cell is stored within the nucleus as helical DNA. This DNA is tightly wound around histones as chromosomes. To produce daughter cells, the chromosomes (total number of chromosomes (2n)) are copied before the cell splits into two daughter cells. This process is known as mitosis, and occurs in cell division and growth processes. Two new nuclei are formed, along with identical cells. These are the same as the parent cell and the chromosome number (2n) is maintained. Conversely in meiosis, the number of chromosomes (2n) is halved through meiotic divisions, producing 4 (n) germ cells (sperm or eggs), each containing half the number of chromosomes as its parent cell.
During the process of prophase I one the nuclear envelope containing chromosomes has only partly broken down homologous chromosomes are joined together by proteins and a complex or pairing call synapsis- corresponding genes on chromatids are aligned precisely. The syanpsis allows for crossing over which is the exchange of segments of chromosome, between non-sister homologous or similar chromatids crossing over happens at chiasmata, the point where non-sister chromosomes are joined.
Crossing over contributes to genetic variation and diversity; novel gene combinations in gametes are formed, which are not present in parent chromosomes. Genetic diversity describes all the genetic characteristics or traits within a species.
Learn more about mitosis at brainly.com/question/4303192
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The controlled experiments are performed by the scientists, when they want to study the changes in the sample on changing a single variable. So, the correct answer is option (b).
In case, all variables are kept same, no changes would be observed in the experiment sample. A controlled experiment can be performed on living thing as well as non living. But, controlled experiment cannot be performed on the things which are influenced by a lot of variables, as they cannot create realistic results. So, the option (a), (c), and (d) are incorrect.
The answer is c because curies release energy from the radiation
Oh I know this, It narrows down its characteristics here is an example:
The first step in the key will be organized the following way:
1. a. wings covered by an exoskeleton
b. wings not covered by an exoskeleton
Next, the statements need to lead the observer to the next step to narrow the identification further:
1. a. wings covered by an exoskeleton go to step 2
b. wings not covered by an exoskeleton .go to step 3
Step 2 needs to consist of a pair of statements that will allow for the identification of the ladybug and the grasshopper:
2. a. body has a round shape .ladybug
b<span>. body has an elongated shape .grasshopper</span>
Two ethical issues of using Biotechnology are Affordability and Privacy. Two social issues of Biotechnology are Harm to the environment and Bio-terrorism.
<u>EXPLANATION: </u>
- The most concerning ethical issue of using biotechnology is the cost and access to new treatments.
- The drugs that break clots that cause heart attacks, for example, are extremely expensive and so the common people cannot afford them.
- The second ethical issue is Privacy.
- The technology can decode the human genome which might reveal the future health information of a person.
- The first social issue of using biotechnology is the harm to the environment.
- It is not sure how will the ecosystem react when a new organism is introduced in the ecosystem.
- Another social issue is that terrorists might make new superbugs or infectious viruses, using biotechnology, which might not have any cure.
