<h2>Answer:</h2>
a. one allele from each parent
<h2>Explanation:</h2>
An allele in biological sciences is one of the possible forms of a gene that it can inherit. Most genes have two alleles, a dominant allele and a recessive allele. When Gregor Mendel crossed a tall plant with a short plant, the F1 plants inherited an allele for tallness from the tall parent and an allele for shortness from the short parent.
In prophase 1:
Chromosomes become visible, crossing-over occurs, the nucleolus disappears, the meiotic spindle forms, and the nuclear envelope disappears.
In metaphase 1:
The pairs of chromosomes (bivalents) become arranged on the metaphase plate and are attached to the now fully formed meiotic spindle. The centrioles are at opposite poles of the cell.
1. Answer: A
Explanation: For a cell to form proteins, the specific types of proteins are coded for by the genes in DNA (found in the chromosomes of the nucleus). To produce proteins, the genes are first transcribed by RNA polymerase to form messenger-RNA. The mRNA is then translated into proteins by ribosomes in the cytoplasm of the cell.
2. Answer: B
Explanation: Translation of genes into proteins is dependent on the sequence of nucleotides. They are translated in sequences of 3 nucleotides known as codons. Therefore adding a nucleotide on a piece of DNA causes what is referred to as a frame-shift mutation. The 3 sequences (of codons) is interrupted and shifted by one nucleotide. Therefore, the codons change and the amino acids translated will also change.
3. Answer: A
Expanation: Producers are significant in a food chain because they incorporate the energy of the sun into the food chain. This is why they are at the base of the food chain and have the largest biomass. They are consumed by primary consumers which are consumed by secondary consumers which are consumed by tertiary consumers and so on.
4. Answer: D
Explanation: Plants are consumed by herbivores. Therefore, a decrease in plant population due to drought was resulted to decrease in herbivore population. This is due to stiff competition by the herbivores for the scarce plant population. Carnivores consume herbivores. Due to a decrease in the herbivore population, then the carnivore population would also decrease.
5. Answer: A
Explanation: Burning of fossil fuels emits carbon dioxide gas which is a greenhouse gas. Greenhouse gas traps infrared wavelength of lights hence warming up the atmosphere, causing global warming. Reduction in use of fossil fuels will hence alleviate an increase in global temperature hence protect coral in the oceans from bleaching.
Human,increase population and Overharvesting
