Answer:
In human males, meiosis occurs in the seminiferous tubules of the testicles while in females, it occurs in cells called as oogonia. In males, meiosis occurs at puberty while in females it occurs right at birth.
Explanation:
Answer:
Eyelashes, wing of a fly, feather of an owl, the tip of your nose, the horn of a goat, your kidney, a maple leaf, a blade of grass, claw of a crab, and petal of a rose.
Explanation:
You have to ask yourself on each one if it is living or non-living.
All answer choices are correct in soil conservation techniques prevents erosion.
<u>Explanation:</u>
- Decreasing tillage yields crops to settle in the soil preferably than being broken at the end of a season. The gain of no-till farming is consecutive to the soil structure, which transmits more deposits on the exterior to stand up against severe water and wind situations.
- With contour ploughing, preferably of seeding crops in straight lines, crops are planted based on the form lines of the area to form stores that save rainwater and lessen top-level soil erosion.
- Terracing is the habit of producing almost level areas in a hillside area. Terraces are shielded from erosion by other soil restrictions.
Ans.
Sickle-cell disorder shows defected red blood cells, due to mutation in gene that code for hemoglobin. The mutated genes for sickle-cell disease are found in higher percentage of sub-Saharan African population as it provides protection against malaria as compared to population of United States.
Malaria is common in sub-Saharan Africa region and there, natural selection favored gene for sickle cells, because it might be beneficial to people having sickle cell disease that makes them able to survive in such condition and transmit their genes to offspring.
On the other hand, in those Africans, who moved to United States, where malaria is uncommon or absent, natural selection favored normal, wild type genes, resulting in fewer people with defected sickle cell.
Thus, the evolutionary process behind this is 'natural selection.'
