Answer:
Hemophilia is a x-linked recessive inherited bleeding disorder. in this disease blood does not clot properly due to the decreased level of blood clotting factor VIII (8) or factor IX (9).
In x-linked recessive condition, the disease is transmitted from father (affected male) to his daughter and mother (affected female) to her son and skip of generation getting affected is also occurs.
- there will be 50% chance of her (S.R.) each son to be affected with hemophilia.
Explanation:
Hemophilia is caused due to mutation of one gene which is responsible for the making of proteins of blood coagulation factor viii or ix. the affected person bleeds continuously from any injury and that can cause serious issues.
here,
grandfather of s.r is affected (xₐy) and grandmother is normal (xx) will produce
↓
s.r's mother who is a carrier (xₐx) [as xₐy and xx will produce 100% carrier xₐx daughter]
↓
s.r's mother is a carrier (xₐx) but her father is normal (xy) will produce,
↓
s.r who has 50% chance of being carrier (xₐx) and 50% chance of being normal (xx) [as she is the only child] and she has a normal (xy) partner, they will give,
↓
- if s.r is a carrier (xₐx) then one of her son will be affected (xₐy) [as xₐx and xy =xₐy]
- if s.r is normal (xx) then her son will be normal (xy) [as xx and xy will give xy]
here,<u> 50% chance of her son to be affected with hemophilia</u> [as S.R of being affected is more considerable].
Mutations are simply a change in genes. So mutations usually result in variation of an organism that can be good or bad. Some mutations can result in physical and mental disorders like Stockholm disease or down syndrome, Where else some mutations can cause immune to diseases that are harmful.
The hypothesis would be: Consumption of a single apple every day will reduce the number of visits to the doctor.
The hypothesis is a proposed explanation that is a starting point for further investigations. So, in this case, we assume that eating one apple a day will keep us healthy, without the need for the doctor.
When the moon gets between the earth
Ans.
Human reproduction involves release of sperm (male gamete) and egg (female gamete) and their fusion to form zygote that develops into embryo. In females, an egg is released each month as a part of a monthly cylce, called menstrual cycle. The release of egg is termed as ovulation, in which tiny eggs are send into the fallopian tubes for fertilization.
Hence, the correct answer is 'a). an adult female usually releases an egg from an ovary each month.'
