There are a couple features unique to mammals, here are some:
1. Mammary Glands- evolved from modified sweats glands, these are used to create milk for offspring. Only females produce this milk.
2. Hair- this is an adaptation that provides insulation to keep the animal warm, provide protection of the skin, and sometimes camouflage the animal through the hair's color patterns.
3. Sweat glands- while being unique to mammals, they are not present in all of them. For example, whales do not have sweat glands at all because they live in the ocean!
During meiosis, two successive nuclear divisions happens namely Meiosis I or reduction and Meiosis II or division. In meiosis I, it separate chromosomes after allowing crossing over. In meiosis II, it the then separates each chromosomes by splitting them. This division produces 4 haploid cells.
the choices are Mice live longer lives in the laboratory than in their natural habitats. The lifespan of a mouse is longer if it is a female. or
Mice that eat small amounts of food live longer than those that eat large amounts of food.
Living indicators are species that are sensitive to changes in the environment. For example air pollution can be monitored by looking at lichen, which are sensitive to sulphur dioxide in the air. The number of lichen at a particular location indicates how clear the air is. Similarly, mayfly larvae are good indicators for water pollution because they're sensitive to the concentration of dissolved oxygen in water.
Non-living indicators are things like satellites which can measure the temperature of the sea surface, weather stations that measure atmospheric temperature, rain gauges to measure rainfall, and dissolved oxygen meters to measure concentration of dissolved oxygen in water.
