Describes the courtship behavior of the male cichlid.
QUESTION POSTED AT 26/03/2020 - 03:27 PM
QUESTION POSTED AT 26/03/2020 - 03:27 PM
The correct answer is option D, decreased variation in tail feather color because the only reason for variation was selection pressure
According to Charles Darwin, traits that help an individual in selecting mates are favored by the sexual selection while all other normal traits are favored by natural selection.Thus , it is believed that this sexual mating pressure among the male peacocks produce large variation in the color and pattern.The male peacocks compete with each other to attract the female on the basis of their colorful tails and its varied patterns.
ANSWERED AT 29/03/2020 - 11:15 PM
QUESTION POSTED AT 29/03/2020 - 11:15 PM
Answer: C. improved soil quality: increased humus and water retention.
An ecological succession brings change in the type of living species residing in an ecosystem with respect to changes that occur in the abiotic (non-living factors) with respect to time.
A region affected by a retreating glacier will not be suitable for the growth of living species. The soil may be lacking minerals and will be in the permafrost condition. So for the initiation of succession the improvement in soil an important abiotic factor is required. The improved soil quality will allow the accumulation of organic and inorganic minerals by physical and biological processes. This will help in formation of humus and water retention.
ANSWERED AT 28/03/2020 - 12:55 PM
QUESTION POSTED AT 28/03/2020 - 12:55 PM
ANSWERED AT 28/03/2020 - 12:45 PM
QUESTION POSTED AT 28/03/2020 - 12:45 PM
ANSWERED AT 28/03/2020 - 12:27 PM
QUESTION POSTED AT 28/03/2020 - 12:27 PM
ANSWERED AT 28/03/2020 - 12:22 PM
QUESTION POSTED AT 28/03/2020 - 12:22 PM
ANSWERED AT 28/03/2020 - 12:05 PM
QUESTION POSTED AT 28/03/2020 - 12:05 PM
What is an Earthquake
Earthquakes are vibrations in the earth's crust They occur along all plate boundaries but are more destructive usually at destructive plate boundaries
How are they measured
The magnitude or size of an earthquake can be measured by an instrument called a seisometer and are shown on a seismograph. The earthquakes are measured on the Richter scale from a value of 1 to 10. Each level of magnitude is 10 times more powerful than the previous. Therefore a level 7 is 100 time more powerful than a level 5.
Why do some earthquakes cause more damage than others?
Some earthquakes take place in rural areas where few people live and little is damaged
If they occur near large urban areas with many people, transport services, large buildings and services such as gas and electricity - there can be a great amount of deaths and damage
In Poor countries - LEDC's they have poorly built buildings, few emergency facilities, and the equipment to help rescue people - a good term to use is that they have a poor infrastructure.
In rich countries - MEDC's such as the USA they prepare for an earthquake with drills and have a great deal of trained emergency personnel and equipment to go to help the injured. They also try to build to withstand earthquake damage - ie The Transamerica building
The time of day can be important - If the earthquake hits when it is the rush hour or when there is a large number of people located in a certain area - this can cause a great loss of life
Obviously if they occur near to coasts then Tsunamis can cause a great deal of damage and deaths such as the 2004 Boxing Day Tsunami
ANSWERED AT 28/03/2020 - 12:00 PM
QUESTION POSTED AT 28/03/2020 - 12:00 PM
ANSWERED AT 28/03/2020 - 11:45 AM
QUESTION POSTED AT 28/03/2020 - 11:45 AM
The correct answer is option C.
The path of oxygen from the atmosphere to the lungs can be described from the nasal cavity to the alveoli. The oxygen is inhaled with air during the breathing process that travels from the nasal cavity to the pharynx that is tube or tract where mouth or oral cavity and nasal cavity combined. Oxygen moves from pharynx to the larynx and then to trachea or the windpipe.
The trachea is a tube that extended to the larynx to the 2 primary bronchi. Oxygen moves from the trachea to the bronchi. Bronchi are the main passage of oxygen to the lungs. Bronchi shuttle air to and from the lungs. These are of three types and oxygen travels into each in order first primary bronchi then secondary and in last to tertiary bronchi and bronchioles and ultimately to the site of gas exchange called alveoli.
Pathway - nasal cavities > pharynx > trachea >bronchi (primary bronchi (right & left) > secondary bronchi > tertiary bronchi)> bronchioles > alveoli.
Thus, the correct answer is option C.
ANSWERED AT 28/03/2020 - 11:27 AM
QUESTION POSTED AT 28/03/2020 - 11:27 AM
Answer: B Gymnosperms produce male cones and female cones, and the pollen from a male cone fertilizes the egg inside a female cone.
Gymnosperms are terrestrial plants, which lacks flowers. The ovule or seeds are remains naked in hard woody structures called as cones. In the gymnosperms the green sporophyte generates cones that contains male and female gametophytes. A male cone consists of microsporophylls where male gametophyte also called as pollen are produced and released into the wind. The wind act as a agent for pollinating the female gametophyte present in the female cone. Inside the female cone the megaspore mother cell produces four haploid megaspores, one megaspore divide itself to form the female gametopyte. The fusion of the pollen with the female gametophyte produces diploid zygote, which later on divides to form the embryo.
ANSWERED AT 28/03/2020 - 11:15 AM
QUESTION POSTED AT 28/03/2020 - 11:15 AM
ANSWERED AT 28/03/2020 - 11:05 AM
QUESTION POSTED AT 28/03/2020 - 11:05 AM
ANSWERED AT 28/03/2020 - 11:01 AM
QUESTION POSTED AT 28/03/2020 - 11:01 AM
ANSWERED AT 28/03/2020 - 10:51 AM
QUESTION POSTED AT 28/03/2020 - 10:51 AM
ANSWERED AT 28/03/2020 - 10:50 AM
QUESTION POSTED AT 28/03/2020 - 10:50 AM
ANSWERED AT 28/03/2020 - 10:48 AM
QUESTION POSTED AT 28/03/2020 - 10:48 AM
ANSWERED AT 28/03/2020 - 10:45 AM
QUESTION POSTED AT 28/03/2020 - 10:45 AM
ANSWERED AT 28/03/2020 - 10:19 AM
QUESTION POSTED AT 28/03/2020 - 10:19 AM
Mitosis is the type of cell division that can be used by asexually reproducing organisms.
Mitosis is a sequence of events that, in the end, one cell, called the mother cell, gives rise to two other cells, the daughter cells. The main feature of mitosis is that daughter cells have the same number of chromosomes as the mother cell. Besides that, no genetic recombination occurs during the process, that is, daughter cells are copies of the mother cell. Thus, this type of cell division is related to asexual reproduction, organism or colony growth and tissue regeneration.
Meiosis, in turn, is somewhat different. Although it is also a sequence of events, in meiosis the parent cell gives rise to four other cells. The main feature is that these four generated cells contain only half of the parent chromosomes. Thus, meiosis relates to the formation of gametes and sexual reproduction.
ANSWERED AT 28/03/2020 - 10:18 AM
QUESTION POSTED AT 28/03/2020 - 10:18 AM
ANSWERED AT 27/03/2020 - 12:51 PM
QUESTION POSTED AT 27/03/2020 - 12:51 PM
ANSWERED AT 27/03/2020 - 10:16 AM
QUESTION POSTED AT 27/03/2020 - 10:16 AM
ANSWERED AT 27/03/2020 - 10:10 AM
QUESTION POSTED AT 27/03/2020 - 10:10 AM
ANSWERED AT 27/03/2020 - 09:49 AM
QUESTION POSTED AT 27/03/2020 - 09:49 AM
ANSWERED AT 26/03/2020 - 03:28 PM
QUESTION POSTED AT 26/03/2020 - 03:28 PM
ANSWERED AT 26/03/2020 - 02:22 PM
QUESTION POSTED AT 26/03/2020 - 02:22 PM
a) these traits are carried only on the x chromosome and since there is no matching gene on the y chromosome, the traits are expressed more readily in males.
Hemophilia, color blindness, and duchenne muscular dystrophy are disorders which are caused by X-linked recessive mutations which means that even if a mutation occurs in a gene of only one X chromosome then the phenotype will be expressed in the males because they are hemizygous for the gene. By hemizygous we mean to say that males have one X and one Y chromosome so a gene present on X chromosome will not find match on the Y chromosome and the mutation will express readily.
In contrast to this, in case of females who have two X chromosomes, the mutation in one X chromosome may be suppressed by another X chromosome in heterozygous condition i.e. if another X chromosome has healthy gene (wild type gene). In case of females the diseased phenotype will only appear if they are homozygous for the mutation.
ANSWERED AT 26/03/2020 - 02:06 PM
QUESTION POSTED AT 26/03/2020 - 02:06 PM
ANSWERED AT 26/03/2020 - 01:58 PM
QUESTION POSTED AT 26/03/2020 - 01:58 PM
the very basic properties of water
high surface tension
high specific heat
how does this help a polar bear, some of it is a stretch but possible benefits
pH - good drinking water, good for marine ecosystem for food
high specific heat - can absorb lots of heat before the temperature rises, polar bears exist naturally in cold environments. (ice) - maybe can tie this in with the natural hibernation cycle
high surface tension - I'm assuming the polar bear walks on the ice at times to get fish
as a good solvent - its probably good that most things dissolve in water, otherwise we would have a lot of floating gunk on top of the water
outside of this, can't give you much more. it has been noted in Shishmaref Village that the ice caps melting is leading to a lack of water in higher mountain areas and polar bears are coming down from the mountain ice cap areas to find food and water
ANSWERED AT 26/03/2020 - 01:33 PM
QUESTION POSTED AT 26/03/2020 - 01:33 PM
ANSWERED AT 26/03/2020 - 12:54 PM
QUESTION POSTED AT 26/03/2020 - 12:54 PM
The intertidal zone is the area of the seafloor between high tide and low tide. It bridges the gap between land and water. Tide pools, estuaries, mangrove swamps and rocky coastal areas are all part of the intertidal zone.
The water above the continental shelf is the neritic zone. Underwater forest of kelp and grassy meadows of sea grass are home to tiny fish, green turtles, sea cows, seahorses and tiny shrimp. Coral reefs have thousands of animals and plants that live in the waters of the neritic zone.
Open ocean zone
The open ocean zone lies beyond the continental slope and contains 65% of the water in the oceans. This zone is divided further into three subzones. The sunlit zone is where photosynthesis takes place. Plankton and jellyfish are drifters that inhabit this zone. Most animals living in the open ocean live in the sunlit zone.
Below the sunlit zone is the twilight zone where some light penetrates the ocean to a depth of 3000 feet. Viper fish, firefly squid, and the chambered nautilus live in this zone. The midnight zone extends from a depth of 3000 feet to the seafloor. Animals found in this zone include the giant squid, deep sea hatchetfish and bioluminescent jellyfish.
ANSWERED AT 26/03/2020 - 11:44 AM
QUESTION POSTED AT 26/03/2020 - 11:44 AM
ANSWERED AT 26/03/2020 - 11:42 AM
QUESTION POSTED AT 26/03/2020 - 11:42 AM