Answer:
Meiosis is a special type of cell division in sexually-reproducing organisms used to produce the gametes, such as sperm or egg cells. It involves two rounds of division that ultimately result in four cells with only one copy of each chromosome.
Explanation:
It adds bases in only one direction.
Answer:
B
Explanation:
The 3'-end of the reverse primer (3'-TTGGCCAATGG---5') is complementary to the forward primer (5'---AACCGGTTACC-3') and thus reduces the ability of the primers to bind to the targeted DNA sequence. There is possibility of hairpin loop formation or primer dimmers formation
Complete question:
Imagine that a newly discovered, recessively inherited disease is expressed only in individuals with type O blood, although the disease and blood group are independently inherited.
A normal man with type A blood and a normal woman with type B blood have already had one child with the disease. The woman is now pregnant for a second time.
Assuming that both parents are heterozygous for the gene that causes the disease, what is the probability that the second child will also have the disease? Express your answer as a fraction using the slash symbol and no spaces (for example, 1/2).
Answer:
The probability that the second child will also have the disease is 1/16.
Explanation:
<u>Available data:</u>
- Two genes independently inherited: one for blood type, the other for disease
- Man with type A blood x Woman with type B blood
- Both parents are heterozygous for the gene that causes the disease; Dd
If the man has A blood, and the woman has B blood, and they already have an affected child, this means that they must be heterozygous for blood type too.
Cross:
Parentals) AiDd x BiDd
Gametes) AD Ad iD id BD Bd iD id
Punnett square) AD Ad iD id
BD ABDD ABDd BiDD BiDd
Bd ABDd ABdd BiDd Bidd
iD AiDD AiDd iiDD iiDd
id AiDd Aidd iiDd iidd
F1) <u>Genotype</u>:
1/16 ABDD
2/16 ABDd
1/16 ABdd
1/16 AiDD
1/16 BiDD
2/16 AiDd
2/16 BiDd
1/16 Aidd
1/16 Bidd
1/16 iiDD
2/16 iiDd
1/16 iidd
<u>Phenotype:</u>
3/16 A/B normal
4/16 A normal
4/16 B normal
3/16 0 normal
1/16 0 affected by the disease.
Answer:
The periosteum is one source of precursor cells which develop into chondroblasts and osteoblasts that are essential to the healing of bone. Other sources of precursor cells are the bone marrow (when present), endosteum, small blood vessels, and fibroblasts.
