Explanation:
B) False
Multiple mutations in several protooncogenes and tumor suppressor genes are required to form cancer
Cancer-causing genes, or oncogenes, develop from protooncogenes which regulate normal cell division. They may undergo mutations that alter gene expression, disrupt cell regulation and lead to the transformation of normal cells into tumor cells- their resulting proteins are abnormal or not formed. Tumor suppressor genes, which can halt unregulated cell growth and division, may also become mutated.
Each individual inherits 2 copies of a gene from their parents- a single mutation in one of these does not directly lead to cancer. Multiple activated oncogenes, in turn produce damaged, non functional proteins and together contribute to forming cancers.
Further Explanation:
During the process of cell division, spontaneous changes within the genome can arise. These mutations are errors occur when copies of the DNA within the cell are made; mutations may range from small changes called single nucleotide polymorphisms, to large scale deletions, and additions which span multiple genes. There are two types:
- somatic: these only occur within certain cells, and arise from environmental factors such as UV light
- hereditary: occur within germ cells of the parent and later the fertilized egg which forms a zygote; these are present within all cells of the new organism.
Sequences of DNA make up genes which can have different forms called alleles. DNA, which makes up the genotype, is transcribed into mRNA and later translated into amino acids which are linked together by rRNA to form proteins which make up the phenotype of an organism. Mutations in DNA sequences affect the corresponding mRNA and thus the protein encoded.
Learn more about mutations at brainly.com/question/4602376
Learn more about DNA and RNA at brainly.com/question/2416343?source=aid8411316
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Explanation:
asexual only needs one parent and serial needs 2 parents
asexaul animals reproduce via mitosis and sexual animals via mieosis
The
statement that best supports that belief is “both have cell wall made
of cellulose, store food material as starch, and have chlorophyll a and chlorophyll
b”.
The green algae are a
large, informal grouping of algae consisting of the Chlorophyte and Charophyte
algae, which are now placed in separate Divisions. The land plants or
Embryophytes are thought to have emerged from the Charophytes.
The correct answer between all
the choices given is the first choice or letter A. I am hoping that this answer
has satisfied your query and it will be able to help you in your endeavor, and
if you would like, feel free to ask another question.
Answer/Explanation: On Mercury temperatures can get as hot as 430 degrees Celsius during the day and as cold as -180 degrees Celsius at night.
Mercury is the planet in our solar system that sits closest to the sun. The distance between Mercury and the sun ranges from 46 million kilometers to 69.8 million kilometers. The earth sits at a comfy 150 million kilometers. This is one reason why it gets so hot on Mercury during the day.
The other reason is that Mercury has a very thin and unstable atmosphere. At a size about a third of the earth and with a mass (what we on earth see as ‘weight’) that is 0.05 times as much as the earth, Mercury just doesn’t have the gravity to keep gases trapped around it, creating an atmosphere. Due to the high temperature, solar winds, and the low gravity (about a third of earth’s gravity), gases keep escaping the planet, quite literally just blowing away.
Atmospheres can trap heat, that’s why it can still be nice and warm at night here on earth.
Mercury’s atmosphere is too thin, unstable and close to the sun to make any notable difference in the temperature.
Space is cold. Space is very cold. So cold in fact, that it can almost reach absolute zero, the point where molecules stop moving (and they always move). In space, the coldest temperature you can get is 2.7 Kelvin, about -270 degrees Celsius.
Sunlight reflected from other planets and moons, gases that move through space, the very thin atmosphere and the surface of Mercury itself are the main reasons that temperatures on Mercury don’t get lower than about -180 °C at night.
Answer:
The correct answer will be option-B.
Explanation:
Sertoli cells are the large somatic cells present in the testis which helps in the formation of spermatozoa. The Sertoli cells create a suitable environment for the production and maturation of the sperms as they produce certain molecules which nourishes the sperms.
The Sertoli cells act as a barrier between the testis and blood and secrete enzymes like inhibin. They eliminate the apoptotic germ cells and also produce seminiferous fluid to nourish the sperm. They do not play any role in primary spermatocytes.
Thus, Option-B is the correct answer.
