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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Light reaction occurs in presence of light while in dark reaction light is not needed
Actively dividing eukaryote cells pass through a series of stages known collectively as the cell cycle: two gap phases (G1 and G2); an S (for synthesis) phase, in which the genetic material is duplicated; and an M phase, in which mitosis partitions the genetic material and the cell divides.
<span><span>
G1 phase. Metabolic changes prepare the cell for division. At a certain point - the restriction point - the cell is committed to division and moves into the S phase.</span><span>
S phase. DNA synthesis replicates the genetic material. Each chromosome now consists of two sister chromatids.</span><span>
G2 phase. Metabolic changes assemble the cytoplasmic materials necessary for mitosis and cytokinesis.</span><span>
M phase. A nuclear division (mitosis) followed by a cell division (cytokinesis).</span></span>
The period between mitotic divisions - that is, G1, S and G2 - is known as interphase.
<span>Mitosis is a form of eukaryotic cell division that produces two daughter cells with the same genetic component as the parent cell. Chromosomes replicated during the S phase are divided in such a way as to ensure that each daughter cell receives a copy of every chromosome. In actively dividing animal cells, the whole process takes about one hour.</span>
Answer:
a) Acetylcholine is degraded by acetylcholinesterase.
Explanation:
After it binds for its receptor on the plasma membrane of the postsynaptic cell, acetylcholine must be removed in order to prevent repeated stimulation. Acetylcholinesterase is enzyme for the inactivation of acetylcholine, present at all cholinergic synapses. This enzyme hydrolyses acetylcholine and breaks it to the acetate and choline. Choline can be reused for the synthesis of the new acetylcholine molecule so it is taken back into the presynaptic cell.
Answer:
The correct answer would be They comprise the Calvin cycle.
Calvin cycle refers to the set of chemical reactions taking place in the stroma of the chloroplast in which carbon is fixed into food (glucose). The whole process is divided into three stages namely: fixation, reduction, and regeneration (ribulose bisphosphate or RuBP).
It takes place in light-independent reaction of the the photosynthesis.
It does not require light energy to carry out the reactions however, it depends upon the products of light reaction (ATP and NADPH).
Fixation of one molecule of glucose requires 6 molecules of carbon dioxide, 9 ATP and 6 NADPH.
The fixation of carbon is catalyzed by an enzyme RuBisCO.
