Answer:
D. Selection has led to decreases in the size of fish at the age of reproductive maturity.
Explanation:
The larger body size of the fishes is not an adaptive trait as it reduces the survival chances of these fishes. The process of natural selection tends to increase the frequency of the traits that increase the survival fitness of the organisms. Here, the fishes with smaller body size at the reproductive age have greater chances of survival and would reproduce more to leave more progeny. Over the generations, the selection pressure would increase the proportion of fishes that are smaller during reproductive age.
Answer:
Placenta
Explanation:
The term for the premature separation of the highly vascular structure that acts as communication between the mother and the embryo is the placenta.
The Placenta develops in a woman's uterus during pregnancy. It helps provide the necessary nutrients and remove the needed waste from the baby's blood.
Answer:
The correct answer would be -
1- YR, Yr, yR and yr.
2. Yr, yR
3. YR, yr
4. YR, Yr, yR & yr
Explanation:
A mature male or female haploid germ cell that fuses with another gamete of the opposite sex during the process of fertilization to make a zygote in sexual reproduction.
The law of Independent Assortment presented by Mendel says that alleles for different traits are passed and assort independently of one another in the gametes.
1. If Y and R on different chromosomes then they will produce four gametes and assort independently - YR, Yr, yR & yr.
2) If Y and R on the same chromosomes and no crossing over occurs then they will produce only two gametes as Y and R will not come together - Yr & yR.
3). if dominant Y and recessive r are on the same chromosome, no crossing over then only two gametes will form as Y and r will not assort together - YR & yr.
4). if dominant Y and R are on the same chromosome, 50% crossing over produces 4 types of gametes, YR, Yr, yR & yr.
Answer:
by the increased temperature they have
Explanation:
when people are sick the doctors have to know how sick the person is
