Answer:
In guinea pigs, the gene for black fur, B, is dominant over the gene for white fur, b. Complete the Punnett square below to show the results of one possible cross between two guinea pigs with black fur.
BB X Bb = BB, Bb, BB, Bb
Explanation:
From the analogy shown, it is obvious that both parents are gene with black fur. During such crossing, the offspring are two homozygous dominant black fur and two heterozygous dominant black fur
I think is A or D
............................. a
Answer:
The correct answer is - 3/16 or 18.75% portion will be resistant to both Bt and DDT.
Explanation:
It is given that bollworms that are susceptible to Bt are represented by either RR or Rr and resistance one are shown by rr genotype and bollworms that are resistant to DDT are represent TT or Tt genotype and susceptible to DDT have tt genotype.
Cross: RR tt with rr TT
Gametes: Rt and rT
F1 cross:
RT
rT RrTt ( susceptible Bt and resistant DDT)
F1 Cross with F1
Gametes: RT, Rt, rT and rt
cross:
RT Rt rT rt
RT RRTT RRTt RrTT RrTt
Rt RRTt RRtt RrTt RrTt
rT RrTT RrTt rrTt rrTt
rt RrTt Rrtt rrTt rrtt
The bold genotypes are the three out of 16 that are resistant to both DDT and Bt.
Answer:
D
Explanation:
Sample D will undergo the fastest rate when subjected to chemical weathering.
What is weathering?
- It is the physical disintegration and chemical decomposition of rocks to form sediments and soils.
- Physical weathering is also known as mechanical weathering. It entails breaking rocks into smaller sized chunks.
- Chemical weathering is the decomposition of rocks by chemical action.
From the given choices, option D will have the largest surface area exposed to chemical actions. It has more surface area compared to the others. The more broken a mass is, the more its surface area is.
Reaction rates are affected by:
- Increase in surface area
- Increase in temperature
- Higher concentration
- Increase in pressure
The last cube has the highest surface area and will have the fastest rate of weathering.
