Answer:
Explanation:
The method of reproduction in humans is sexual reproduction: a type of reproduction that occurs when new organisms are produced through the coming together of genetic information from two individuals of different sexes mostly a male and a female (egg cell and the sperm). The genetic information for making the blood cells; the red blood cells genes in particular exists on chromosomes in the nucleus of the sex cells (egg and sperm cell) also called the gametes. Basically, the DNA provides instructions for the production of mostly all of the body's needs.
The genes coding for the sickle cells which is the abnormal red cell is always inherited in the recessive form meaning both parent has to possess one copy each of the defective gene in their DNA. For humans to get one copy of a sickle cell gene and one copy normal gene; it means one of the parents gametes (be it male or female) contributed the defective chromosome and the other normal gene is contributed by the other parent during copulation giving rise to an individual that is heterozygous for the trait
For example, the sperm cell with the defective gene fertilizes the egg cell that has the normal copy of the gene producing an heterozgous individual.
Evolution is caused by genetic mutations that become favorable for survival.
For example if a bird has a mutation that gives it a longer beak and it lives in an environment in which a longer beak lets the bird catch more food- the longer beak becomes a favorable trait.
Now the bird is able to survive “better” thus it lives longer(due to its ability to catch more food). Because of this it reproduces more and passes the trait on to its offspring.
Overtime this mutation takes over the population of birds in the area.
Individual 1 is male individual 2 is female
Answer:
I believe that it is D.
Explanation:
If ice caps are melting, and polar bears use the ice flows to get their food, then the polar bears can't use the ice to get food. so, the polar bears most likely are expanding their diets to adapt to their surroundings. So, polar bears are probably moving off the sea ice and eating other foods.