Answer: If crossing over did not occur during meiosis, there would be less genetic variation within a species. ... Also the species could die out due to disease and any immunity gained will die with the individual. Two types of gametes are possible when following genes on the same chromosomes. If crossing over does not occur, the products are parental gametes. If crossing over occurs, the products are recombinant gametes.
Explanation:
Answer:
Pyruvate kinase
Explanation:
Yeasts convert glycerol and sugars into glyceraldehyde 3-phosphate (G3P) through independent pathways. Then, G3P forms pyruvate and, in some circumstances, pyruvate is converted in ethanol, which can be used as energy sources. If the mutation affects any reaction before G3P formation, it will only affect yeast growing either on sugar or pyruvate but not both.
Pyruvate kinase is the only enzyme on the list acting after G3P is formed and before pyruvate is formed. All other options are enzymes acting only in the formation of G3P from sugars. Meaning that only pyruvate kinase mutants will lack the ability to grow on both sugars and glycerol.
Answer:
This is due to the event of Speciation that happened for the rodents in Island B but not for the rodents in Island C.
Explanation:
- Due to splitting of the population,
- The sub-population of rodents formed in Island B are B1 and B2.
- The sub-population of rodents formed in Island C are C1 and C2.
- In case of Island B, each of the B1 and B2 sub-populations that got split from each other developed certain mutations that were necessary for them to adapt to the particular diverse environment each of them were exposed to, through the period of 50,000 years. These mutations were so varied that reproductive isolation was generated between them that resulted in each of them to develop into different species.Hence, speciation happens here and B1 and B2 are incapable of inter-breeding.
- In case of Island C, each of the C1 and C2 sub-populations that got split might have got exposed to similar environmental change or no environmental change or the environmental change might have been too small to cause drastic change in each of the sub-populations. As a result of this the two sub-populations might have acquired certain mutations to adapt to the environment each of them were exposed to, through a period of 100,000 years. These mutations might not have been too variable or contrasting to cause reproductive isolation between C1 and C2. Hence, no new speciation happens here and C1 and C2 are capable of inter-breeding.
A. Twelve cells with 16 chromosomes each
Pituitary gland.
When you feel stress, the pituitary gland, at the base of the brain, increases its production of the hormone ACTH. This hormone tells the adrenal glands, found at the top of your kidneys, to increase their production of hormones. These stress hormones help you to concentrate, speed your reaction time, and boost your strength. Your hypothalamus also helps your body respond to stress.
