Answer:
a. Heterozygous individuals may pass on their copy of the disease-causing allele to offspring.
Explanation:
Tay-Sachs, which is a recessive lethal disease ---- Let say the recessive lethal diseases is s
∴ it only results when an individual posses two copies of the diseases-causing allele i.e two copies of the disease will be ss.
Now, when two hetrozygous individuals crossed , it is obvious that each can pass on their copy of the disease-causing allele to the offspring.
Let show an illustration for the above statement.
Let the heterozygous individual be Ts, if Ts cross with another Ts;
we will have:
Ts × Ts
T s
T TT Ts
s Ts ss
the offspring are TT,Ts,Ts,ss
We can now see how the Heterozygous individuals pass on their copy of the disease-causing allele to the offspring (Ts).
Answer:
convergent evolution.
Explanation:
When organisms of distantly related species or groups are found in similar environmental conditions, they develop some similar features which are otherwise not present in their ancestral species. This is called convergent evolution. Convergent evolution also results in the development of similar traits in the distantly related organisms that are found in distantly located geographical regions having similar environmental conditions. Therefore, the presence of the same features in rodents and flying squirrels represent convergent evolution.
2019 years have humans been on earth
Answer:
2.048 x 10^6 No. Of Copies
Explanation:
The DNA replication in a PCR works exponentially by using the 2^n where n represents the number of cycles.
For one molecule of DNA = 2^11 = 2048 No. Of Copies
For 1000 Molecules of DNA = 1000 x 2048 = 2.048 x 10^6 No. Of Copies
More than 99 percent of all species, amounting to over five billion species, that ever lived on Earth are estimated to be extinct. Estimates on the number of Earth's current species range from 10 million to 14 million, of which about 1.2 million have been documented and over 86 percent have not yet been described.
